nrg Lex v2.1 System Control Module Instruction Manual
- June 25, 2024
- nrg
Table of Contents
- Lex v2.1 System Control Module
- Technical Specifications
- Product Usage Instructions
- Installation
- Setup and Configuration
- Maintenance and Troubleshooting
- Q: How many zones can be controlled with this system?
- Q: Can this system be expanded for larger installations?
- Q: How does the frost input function work?
- Q: What is the benefit of using isolated inputs/outputs in this
Lex v2.1 System Control Module
“`html
Technical Specifications
-
Power Supply Rating: 230 V~, 15 mA, 50 HZ / 60 HZ, 1 PHASE
-
Power Switching Capacity (Combined Load): Must not exceed 5 A
for all loads -
Boiler Relay Rating: Double Pole Normally Open (DPNO) 5 A
-
Boilers – Boiler Volt Free Control Switches
-
Boiler Supply
-
Clock Supply
-
Boiler Frost Protection
-
Auxiliary Inputs
-
Auxiliary Outputs
-
Operating Temperatures
-
Enclosure Rating
-
Main Fuse: 5 A
-
Boiler/Clock Fusing
-
Zone Fuses
-
Zone Call Indicators
-
Mains Supply Indicators
-
Boiler Call Indicators
-
Auxiliary Call Indicators
-
Transient Suppression (VDR x 2)
-
Terminals
-
Dimensions (L x W x H)
-
Mountable Weight with Enclosure
Product Usage Instructions
Installation
1. Ensure the power supply is disconnected before
installation.
2. Connect the unit to the appropriate power source following
the provided guidelines.
3. Make necessary connections to the boiler, zones, and
auxiliary components as per your system design.
Setup and Configuration
1. Use the Push-Open connections to connect cables of suitable
sizes for easy installation.
2. Configure the zones, boiler control circuits, and auxiliary
inputs according to your heating system requirements.
Maintenance and Troubleshooting
1. Regularly check the LED indicators to identify any issues
with the system.
2. Follow the troubleshooting guide in the manual to address any
operational problems.
Frequently Asked Questions (FAQ)
Q: How many zones can be controlled with this system?
A: The system allows control of up to four zones with individual
fused connections.
Q: Can this system be expanded for larger installations?
A: Yes, the scalability feature enables expansion while
maintaining centralized control, making it suitable for larger
installations.
Q: How does the frost input function work?
A: The optional frost input triggers a boiler call when frost
protection is required, ensuring the heating system responds
appropriately to temperature changes.
Q: What is the benefit of using isolated inputs/outputs in this
system?
A: Isolated inputs/outputs contribute to system safety by
preventing potential electrical issues and enhancing overall
reliability.
“`
INSTALLATION & SYSTEMS DESIGN MANUAL
SAFETY
Warnings and safety precautions Before installing, read all instructions,
including this manual and any related manuals or supplements. Failure to
comply could result in severe personal injury, death or substantial property
damage. A competent person must fit this product in accordance with the
guidance, standards, and regulations applicable to the country or state where
the product is installed. Failure to comply with the relevant guidance,
standards, and regulations could lead to injury, death, or prosecution and
result in substantial property damage. The the correct tools and equipment
must be used when working on the NRG Lex. Be aware of your surroundings and
take precautions to avoid hazards. If you are unsure how to install this
product safely, consult a qualified professional. Once installed, test the
product to ensure that it is working safely. By following these instructions,
you can help to ensure the safety of yourself and others during and after the
installation process.
Connections to the Power Supply The connection method to the mains electricity
supply MUST facilitate complete electrical isolation of the entire
installation. The power supply must be 230 V~, 50/60 Hz, Single Phase.
Attaching the NRG Lex board to multiple phases will cause irreparable damage.
To ensure a single phase, we recommend introducing power only at the Main’s
input terminals (7, 8) and that all other power inputs must derive from
suitable outputs on the board. A double pole switch fused to carry the entire
heating system’s power load with at least 3 mm (1/8″) contact separation in
both poles should be used to serve only the NRG Lex panel. The connection
point to the mains should be readily accessible and, if possible, adjacent to
the NRG Lex unit. Always isolate the AC mains supply before installing or
working on any components that require 230 V~, 50 Hz supply. Only use 0.5 mm2
to 1.5 mm2 cables when connecting to the NRG Lex v2.1 SCM. Wiring external to
the NRG Lex printed circuit board MUST follow current statutory wiring
regulations and any applicable local regulations. Devices attached to NRG Lex
MUST be earthed correctly in accordance with the manufacturer’s
specifications. Note: The zone LED indicator might have a dim light when the
zone is not calling due to induction, but it will glow brightly when the zone
is calling.
Use of RCDs An RCD, short for residual current device, is a critical safety
device engineered to safeguard against potentially lethal electric shocks
caused by contact with live electrical components, such as exposed wires. It
also contributes to reducing the risk of electrical fires. Unlike regular
fuses and circuit breakers, RCDs offer unique personal protection. It is
essential to ensure that the electrical installation employs the correct size
and type of safety device (RCD) when using inverter-driven heat pumps. Pay
attention to the specific requirements for the RCD’s sensitivity to guarantee
the safety and proper functioning of the electrical setup. Additionally, it is
crucial to power the NRG Lex directly through the same supply that passes
through the same RCD. Using an independent power supply for the NRG Lex could
lead to an imbalance in the RCD, potentially causing it to trip.
2
Table of Contents 1. Introduction
………………………………………………………………………………………………………………………………………………………………………………………………….6 2.
Power Supply
……………………………………………………………………………………………………………………………………………………………………………………………….7 3.
Zone
Controls……………………………………………………………………………………………………………………………………………………………………………………………….7
3.1. Clocks and
thermostats……………………………………………………………………………………………………………………………………………………………….7 3.2.
Programmable
Thermostats……………………………………………………………………………………………………………………………………………………. 8 3.3.
Multi-Channel Programmers
…………………………………………………………………………………………………………………………………………………… 8 3.4. Zone
Circulator
Control……………………………………………………………………………………………………………………………………………………………….. 8 3.5.
DHW Recirculation Pump
…………………………………………………………………………………………………………………………………………………………. 8 3.6. 2-Port
Motorised Valves ………………………………………………………………………………………………………………………………………………………………
8 3.7. Fault Finding
……………………………………………………………………………………………………………………………………………………………………………………. 8 3.8.
3-Port Motorised Valve
…………………………………………………………………………………………………………………………………………………………………9 4. Boiler &
Heat Pump Call
Control………………………………………………………………………………………………………………………………………………………..10 5. Boiler
Call Override & Frost
Input………………………………………………………………………………………………………………………………………………………10 6.
Interconnecting Multiple NRG Lex
Units……………………………………………………………………………………………………………………………………….10 7. Auxiliary
Control Relay
…………………………………………………………………………………………………………………………………………………………………………….11 8. Relay
Board Addon
…………………………………………………………………………………………………………………………………………………………………………………..11 9.
System Sketchpad with NRG Lex v2.1
……………………………………………………………………………………………………………………………………………..18
3
FEATURES & BENEFITS
Features: Fused Power Supply: The fused power supply protects the system
components from damage.
Zone Control: Four zones with individual fused 1A connections. The zone blocks
have terminals for clocks, programmers, thermostats, motorized zone valves
and/or zone pumps.
Benefits: Zoned Heating Control: Efficient control of different zones,
ensuring each area receives the desired heating level without wasting energy.
Easy Installation: The “Push-Open” connections and clear LED indicators make
installation and setup easier for installers.
Boiler Power Supplies: Two fused 3A power supplies specifically to protect boilers and provide a reliable power supply for the heating equipment.
Flexibility: Can adapt to various heating system setups with different boiler firing control options and zone configurations.
Boiler Control Circuits: Two boiler control circuits usable for switch-live or
voltage-free controls, providing flexibility when connecting the unit to
various boiler switching types.
LED Indications: LED indicators that show the status of zones, boiler calls,
and auxiliary operations make monitoring the system’s operation easy.
Auxiliary Provision: Auxiliary relay provision with four isolated inputs and
two sets of isolated relay contacts (C, NO, NC) for more complex control
scenarios and integration with other systems.
Frost Input: An optional frost input can trigger a boiler call when frost
protection is required, ensuring the heating system responds appropriately to
temperature changes.
Reliability: Fused power supplies and auxiliary provisions ensure the heating
system’s reliable and stable operation.
Scalability: Scalability feature enables the expansion of the heating system
while maintaining centralised control, which is particularly beneficial for
larger installations.
Advanced Control: The ability to manage pumps, valves, and other auxiliary
components enhances the overall control and performance of the heating system.
Maintenance and Troubleshooting: The LED indicators help identify issues
quickly and simplify maintenance tasks.
Enhanced Safety: Fused power supplies and isolated inputs/outputs contribute
to system safety by preventing potential electrical issues.
Easy Connections: “Push-Open” connections suitable for 0.5 to 1.5 mm2 cable sizes used to simplify the installation process.
Scalability: Scalability allows multiple NRG Lex units to interconnect within a single heating system.
Figure 1: NRG Lex v2.1
4
TECHNICAL SPECIFICATIONS
POWER SUPPLY RATING POWER SWITCHING CAPACITY – (COMBINED LOAD) BOIL RELAY RATING BOILERS – BOILER VOLT FREE CONTROL SWITCHES BOILER SUPPLY CLOCK SUPPLY BOILER FROST PROTECTION AUXILIARY INPUTS AUXILIARY OUTPUTS OPERATING TEMPERATURES ENCLOSURE RATING MAIN FUSE BOILER/CLOCK FUSING ZONE FUSES ZONE CALL INDICATORS MAINS SUPPLY INDICATORS BOILER CALL INDICATORS AUXILIARY CALL INDICATORS TRANSIENT SUPPRESSION (VDR X 2) TERMINALS DIMENSIONS (L x W x H) MOUNTABLE WEIGHT WITH ENCOSURE
230 V~, 15 mA, 50 HZ / 60 HZ, 1 PHASE MUST NOT EXCEED 5 A FOR ALL LOADS DOUBLE
POLE NORMALLY OPEN -DPNO 5 A
2 2 1 1 4 2 SETS OF DOUBLE POLE CHANGEOVER 5 A 0 – 50°C IP20 6.3 A, 230 V ~ T
ANTI-SURGE 3.0 A, 230 V ~ T ANTI-SURGE 4 x 1.0 A, 230 V ~ T ANTI-SURGE 4 1 1 1
YES 0.5 MM2 TO 1.5 MM2 350 x 93 x 58 MM DIN RAIL OR SCREWS 800 G
5
INTRODUCTION
1. Introduction The NRG Lex v2.1 System Control Module (SCM) from NRG
Awareness is a reliable operating system for your heating system. The design
layout makes installing and following the system operation easy, making it
safer and easier to perform routine maintenance and fault-finding. This manual
is a practical guide for safely and correctly installing the NRG Lex v2.1 SCM,
associated time/ temperature controls and connection methods to various third-
party heat sources. The NRG Lex v2.1 SCM meets the performance requirements of
most domestic and light commercial heating systems, offering precise control
of your design strategy for years of trouble-free operation. This manual
explains how to: · Understand the NRG Lex v2.1 SCM · Install the NRG Lex v2.1
SCM, · Wire the NRG Lex v2.1 SCM to configure up to
four zoned control circuits and two heating appliances connected in parallel.
Basic System Control Module Layout The NRG Lex v2.1 is divided logically into
five different areas with various purposes: · Power supplies, · Boiler switch
controls, · Auxiliary controls for supplementary functions, · Zone time &
temperature connections for pumps
or motorised valves, · Earth blocks
Figure 2: NRG Lex v2.1 Layout
6
CONNECTIONS OVERVIEW
Use Correct Earthing Procedures
F1: 1 Amp Zone A
F2: 1 Amp Zone B
F3: 1 Amp Zone C
F4: 1 Amp Zone D
F5: 3 Amp Clock
F6: 3 Amp Blr 1
F7: 3 Amp Blr 2
F8: 6 Amp Mains
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Boiler On
DO NOT COMBINE MAINS AND LOW VOLTAGE
CONTACTS WITHIN THE CONTACTS OF THE SAME RELAY
Aux On
Clock Boiler 1 Boiler 2 Mains
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
Figure 3: NRG Lex v2.1 Simplified layout for schematics with the internal tracks highlighted.
F5: 3 Amp Clock
F6: 3 Amp Blr 1
F7: 3 Amp Blr 2
F8: 6 Amp Mains F2: 1 Amp Zone B
Boiler On
DO NOT COMBINE MAINS AND LOW VOLTAGE
CONTACTS WITHIN THE CONTACTS OF THE SAME RELAY
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
Relay Max
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
12345678 Clock Blr 1 Blr 2 Mains
9 10 11 12 13 14 Frost Blr 1 Blr 2
Figure 4: Power, boiler and frost blocks
N N Blr Call L L B12 B11 B10 B9 B8 B7
Figure 5: Zone Block B.
SL L N
NL
NC C
Clock
Pump
NO C
Roomstat
Figure 6: Zone Block B with a pump, clock and roomstat.
2. Power Supply When a power supply connects to 7 Live (L) and 8 Neutral (N),
onboard tracks conduct the power to the other Live and Neutral terminals. The
`Mains OK’ LED on the left side of the board will illuminate when the power
supply is on. The main 6.3A fuse (F8) supplies all the other Live terminals
through the other fuses (F1, F2, F3, F4, F5, F6 and F7). Each neutral terminal
directly connects with the others.
Terminals 1-6 provide power to central time/temperature controllers and
permanent power supplies to boilers or other system appliances, each with
independent fuses with a maximum fuse rating of 3A.
3. Zone Controls Zone control blocks A, B, C and D are identical, each with
12 terminals. Terminals 1-3 are permanent live outputs supplied through the
zones’ 1A fuse. Terminals 4 and 5 are connected interally on the board, and so
are terminals 6, 7, 8 and 9. A live into terminals 6, 7, 8 or 9 will light the
zone call LED. Terminal 10 is the boiler call; a live signal into this
terminal will switch the boiler relay.
The printed NRG Lex symbols provide a diagrammatic path, showing the general
zone-control strategy that takes power from terminals 1, 2 or 3, with neutral
terminals 11 and 12 to the respective zones. The terminals usually supply live
power to a zone’s time & temperature controls or a programmable thermostat.
3.1. Clocks and thermostats In Figure 6 above a clock is powered from 1 with
its neutral from terminal 12 and its Switch-Live (SL) back to terminal 4.
Terminal 4 is internally linked to 5 which supplies a room thermostat with a
SL back to terminal 6. Terminal 6 is internally linked to terminals 7, 8 & 9.
Terminal 8 supplies a pump with its neutral from treminal 11 and there is a
link from terminal 9 to 10 to close the boiler relay.
7
ZONE CONNECTION
3.2. Programmable Thermostats As programmable thermostats incorporate time & temperature features, they would connect from a zone live (1, 2 or 3) and switch directly to terminal 6, bypassing terminals 4 and 5.
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
SL L N
NL
Programmable Roomstat
Pump
Figure 7: Zone Block C wired with a programmable thermostat and circulation
pump
3.3. Multi-Channel Programmers When it is preferable to use a multi-channel
programmer for time control of many zones, take power from the central time
control supply live at terminal 1, fused at 3A, and neutral from the adjacent
terminal 2. The switch lives from a multi-channel programmer, which can then
bypass the zone power supply and go directly to terminal 4. If the programmer
has time and temperature control, common with wireless thermostat systems, the
switchlive can go directly to terminal 6.
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock
Clock Power LN
12 Clock
NL
Zone A DHW Pump
NL
Zone B CH Pump
NL
Zone C CH Pump
SL1 SL2 SL3 SL4
4 Channel Wireless Clock
NL
NL
Zone D CH Pump
Zone A DHW
Zone B Heating
Zone C Heating
Zone D Heating
Figure 8: 4 zones wired with a multi-channel programmer and wireless thermostats
3.4. Zone Circulator Control When circulators control the heating of a zoned circuit, they connect in series with the zones’ time and temperature controls. The circulator’s live power connects to one of the zone’s terminals 7, 8, or 9, and the neutral to terminals 11 or 12. The pump’s earth connects to one of the earth blocks.
As pumps do not have auxiliary switching to call a boiler when operating a zone, a switch live link must be supplied to terminal 10 to activate the boiler relay when a zone is calling, typically by linking terminals 9 and 10.
See Figures 6, 7 & 8 for examples of zone circulator wiring.
3.5. DHW Recirculation Pump
Terminals 1-6 may be used for time and/or temperature
control for a domestic hot water recirculation pump. The
pump can be supplied from terminals 7, 8 or 9 as with
normal zone pumps, but omitting the link to terminal 10
will prevent the boiler relay from switching. This method
will keep the DHW recirculation zone independent from
the boiler controls.
CLOCK
STAT
3.6. 2-Port Motorised
LLLLLL
Valves
If any of the four zones is to
D1 D2 D3 D4 D5 D6
control a 2-port motorised valve,
then the power to the valve would connect to the terminals
ZONE D
7, 8 or 9 and its neutral from
11 or 12. The valve’s auxiliary
N N Blr Call L L
microswitch would take its power
D12 D11 D10 D9 D8 D7
(grey) from the fused input, 1, 2
or 3, or terminals 7, 8 or 9, and
the switch live (orange) would
connect to terminal 10. That
connection method will safely
interlock the boiler with the zone SL L N N O G L
call, preventing the boiler from MV
firing unless the control valve has
opened.
Programmable Roomstat
Figure 9: Zone Block D with a motorised valve
3.7. Fault Finding The NRG Lex LEDs will identify when the controls call for a
zone to heat. This indication can also determine if a zone time or temperature
control is faulty by switching each of the two and observing the effect on the
LED.
The LEDs are particularly useful with motorised valved-based installations,
especially when the valve incorporates an LED. The illuminated valve LED will
identify that the time and temperature controls are working, and the NRG Lex
Boiler Call LED will help determine that the valve’s integral microswitch has
closed to call for heat.
8
ZONE CONNECTION
3.8. 3-Port Motorised Valve The key elements to correct 3-port motorised valve
control are typically as follows:
1, Heating Off, DHW Off, – Grey Wire Live
2, Heating Off, DHW On, – No Wires Live
3, Heating On, DHW Off, – Grey and white Live
4, Heating On, DHW On, – White Wire Live
Two NRG Lex zones are required to operate a midposition 3-port motorised valve
where port AB is the valve entry or common port. Valve port B remains open
(typically to the hot water zone) when the valve is not activated, and port A
supplies the heating zone when there is a heating call.
The first (DHW) zone time control and thermostat have two crucial valve
operation functions. In this example, the DHW normally closed or clock `off’
connection supplies power to the grey wire in the valve at terminal C7.
DHW Call (Grey Wire Energised)
Heating & DHW Call (White Wire Only Energised)
The grey wire is de-energised when the DHW controls are calling. Internal switches and other components ensure the motor holds at this mid-point, and the white wire now has live power to pass through a microswitch within the valve and into terminal 10 to call the boiler to heat the zones.
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
Clock
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Power
LN
12 Clock
The 3-port valve will remain open to DHW unless the motor is powered. The
wires are already in place; therefore, when the DHW time control and the DHW
stat call, the power is directed to terminal C10 for the boiler to heat the
water.
Heating Call (Grey & White Wire Energised)
NO C
NC C
DHW Stat
N OWG
3-way MV
NC C
NO C
Roomstat
The heating zone call requires this power at the grey wire to open the valve to the heating position (Port A) and to call the boiler when the zone calls. The power on the grey from the DHW `Off’ position allows the valve to open to heating port A. The heating controls energise the white wire, which goes through the microswitch within the valve and out through the orange wire into terminal D10 on the heating zone to fire the boiler.
On1 Off1 On2 Off2
2 Channel Time Clock
Figure 10: Wiring of a 3-port valve using 2 zones
NL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
B1 B2 B3 B4 B5 B6
C1 C2 C3 C4 C5 C6
D1 D2 D3 D4 D5 D6
ZONE A
ZONE B
ZONE C
ZONE D
N N Blr Call L L A12 A11 A10 A9 A8 A7
N N Blr Call L L B12 B11 B10 B9 B8 B7
N N Blr Call L L C12 C11 C10 C9 C8 C7
N N Blr Call L L D12 D11 D10 D9 D8 D7
NL
Pump Permanently “ON”
SL L N
NL
Clock
Pump
Time control only
Figure 11: Examples of zone wiring
NL
NC C
SL L N
NL
NC C
Pump
NO C
Roomstat
Temperature control only
Clock
DHW Recirculation
Pump
NO C
Thermostat
Time and temperature controlled DHW Recirculation Pump (No Boiler Call)
9
APPLIANCE CONNECTION
4. Boiler & Heat Pump Call Control The double pole Boiler Control – Relay 1 is the heating appliance call relay. The relay can call one or two heat sources using one of the two sets of volt-free contacts, 11 & 12 or 13 & 14.
Any switch-live input into a zone’s terminal 10 (A10, B10, C10 and D10) will switch the boiler relay, generally by having a link between zone terminals 9 and 10.
If terminal 10 on any zone is powered to energise the
boiler control relay, it will remain isolated from all other
zone calls.
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
12345678 Clock Blr 1 Blr 2 Mains
9 10 11 12 13 14 Frost Blr 1 Blr 2
15 16 17 18 19 20
NC1 COM1 NO1 NO2 COM2 N
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20
NC1 COM1 NO1 NO2 COM2 NC2
HEAT PUMP
1 2
EXT EXT
Gas Boiler
HEAT PUMP
VF2
VF1
N
L
Gas Boiler
Gas Boiler with a
permanent live and voltage
PL
free switching.
N
SL
Gas Boiler with a permanent live and
switch live.
Figure 12: Wiring examples of a permanent live and switch live gas boiler (Boiler 1) and volt-free gas boiler (boiler 2).
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
1
2
Figure 14: Wiring examples two heat pumps wired to the NRG Lex. The volt-free
circuit from the heat pumps are wired through the boiler call switches on the
NRG Lex. When the boiler call switches close, the circuit is made, and the
heat pump sees that there is a call for heat and They start running.
5. Boiler Call Override & Frost Input Terminals 9 and 10 are independent
inputs that, when energised, will close the Boiler Control Relay 1 contacts,
11 – 12 and 13 – 14. They have many uses, including frost protection or
overriding the zone-dependent boiler call.
The power for the frost protection thermostat, or any other ancillary
function, is typically taken from Fuse 9 (3A) terminals 27, 28, 29, or 30.
12345678 Clock Blr 1 Blr 2 Mains
9 10 11 12 13 14 Frost Blr 1 Blr 2
15 16 17 18 19 20
NC1 COM1 NO1 NO2 COM2 NC2
Boiler Thermostat(s)
LLL
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
Boiler Thermostat(s)
LLL
SL N PL Oil Boiler
Boiler Pump
L
N
L N
Oil Boiler
Boiler Pump
L
N
Figure 13: Wring example of switch live oil boiler (Boiler 1) and permanent live and switch live oil boiler (Boiler 2).
9 10 11 12 13 14 Frost Blr 1 Blr 2
Figure 15: Frost input and boiler call switches
6. Interconnecting Multiple NRG Lex Units Numerous NRG Lex SCMs can interlink
in series by taking a switch live through the boiler relay of one NRG Lex and
supplying it to the frost input terminal on the next NRG Lex. The last NRG Lex
in the chain will have the system boiler(s) connected to its boiler relay.
10
ADVANCED FUNCTIONS
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
12345678 Clock Blr 1 Blr 2 Mains
9 10 11 12 13 14 Frost Blr 1 Blr 2
without back feeding to any of the other inputs.
Terminals 21a, 22a, 23a and 24a connect in series to the corresponding
numbers, i.e., 23 – 23a. They provide optional additional functionality by
making the switchlive to switch the relay available for other functions. For
example, to operate a biomass stove pump with the same switch live used to
switch over the auxiliary relay and break an oil boiler call circuit.
Boiler On
DO NOT COMBINE MAINS AND LOW VOLTAGE
CONTACTS WITHIN THE CONTACTS OF THE SAME RELAY
Aux On
Relay Contacts Max: 5 Amp
F5: 3 Amp Clock
F6: 3 Amp Blr 1
F7: 3 Amp Blr 2
F8: 6 Amp Mains
F9: 3 Amp 27 – 30
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Relay Cont Max: 5 A
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Boiler Thermostat(s)
LLL
SL N PL Oil Boiler
Boiler Pump
L
N
Figure 16: Two NRG Lex v2.1 boards interlinked. Here the boiler on the lower
NRG Lex will fire when the boiler relay on the upper NRG Lex closes. The live
signal travels from terminal 5 on the lower NRG Lex, through boiler switches
11-12 on the upper board and then into the frost input terminal 9 on the lower
board to fire the boiler.
7. Auxiliary Control Relay The auxiliary controls give the NRG Lex v2.1 great
flexibility to accommodate various auxiliary system options. For example, to
isolate the power to zones that are not required when priority DHW is
required.
The Auxiliary output is a double pole changeover unit with two switches, each
having a common (C), normally closed (NC) and normally open (NO) terminal. The
common and normally closed terminals are usually connected. When energised,
the auxiliary relay switches contacts, breaking the connections between the
common and normally closed terminals and making the connections between the
common and normally open terminals.
Live power for auxiliary functions, fused at 3A, is available at terminals 27,
28, 29, and 30, with Neutrals provided at terminals 25 & 26.
The 4 auxiliary input terminals (21, 22, 23 & 24) are isolated from each
other. Any one input terminal will operate the auxiliary relay (relay 2) when
it receives a 230V supply,
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
15 16 17 18 19 20
NC1 COM1 NO1 NO2 COM2 NC2
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Figure 17: Auxiliary control terminals
8. Relay Board Addon The NRG Lex Relay Board has two electrical double pole
double throw (DPDT) relays, R1 & R2. There are two switches per relay, each of
which has three contacts. The terminals are labelled “C” (Common), “NO”
(Normally Open) and “NC” (Normally Closed). When the relay is de-energised,
the C is in contact with NC. When the relay coil energises, the contacts
swtiches, and C connects to the NO terminal instead of the NC terminal.
A 230VAC power supply connects to the mains input “Power In” terminals. The
Relay Board provides three live outputs: 2 x 230VAC and one 12VDC output. The
DC output can, for example, power a DHW cylinder anode.
A live input is needed on L1 (Relay 1) or L2 (Relay 2) to switch the relays.
The two microswitches on board allow either L1 or L2 to switch their
respective relays or to change contacts on both relays together, allowing one
input to switch both relays simultaneously.
RELAY 1
N0 N0
N0 N0
RELAY 2
N0 N0
N0 N0
12
L OUT L IN L L L1′ L2′
E1 E2 E3 E4 E5 E6
E7 E8 E9 E10 E11 E12
RELAY 1 ON
12 VDC 230 VAC
+ -NL
R2+R1 R1+R2
R2+R2 INPUT R1+R1 INPUT
L1 SWITCHES RELAY 1 & L2 SWITCHES RELAY 2
POWER POWER
OUT
IN
FUSE:
3A
MICRO-SWITCHES 1 & 2 SWITCH RELAY 1 AND RELAY 2 AT THE SAME TIME IN ‘ON’ POSITION
POWER SUPPLY
OK
Figure 18: NRG Relay addon.
11
WIRING SCHEMATICS
Use Correct Earthing Procedures
F5: F6: F7: F8: 6 Am Mains F9: 3 Amp 27 – 30
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Relay Contacts Max: 5 Amp
Earthing
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 6
Zone 4 – Central Heating Zone 3 – Central Heating Zone 2 – Central Heating
Zone 1 – DHW
P1
NL
Zone 1 Pump
NC C
NO C
Zone 2 Roomstat / Cylinder (Break on temp rise)
NL
Zone 2 Pump
SL L N
Zone 1 Timer
SL L N
Zone 2 Timer
NL
Zone 3 Pump
NL
Zone 4 Pump
SL L
Zone 3 Roomstat
SL L N
Zone 4 Programmable
Roomstat
LN
LN
Main Isolated Power Supply
Boiler Thermostat(s)
LLL
SL N PL Oil Boiler
Boiler Pump
L
N
SV TN Oil Boiler
DC
Expansion Vessel
SV
LSD
TN
DHW Pressurised
DC
Figure 19: 4-zone system with an oil boiler and 4 different types of zone control To the right you can see an example mechanical schematic to match the wiring schematic above. This is a 4-zoen system with 3 heating zones and 1 DHW zone. In the wiring schematic the 4 zones are wired in separate ways: Zone A has a timer and a thermostat, Zone B only has a timer, Zone C only has a thermostat and Zone D has a programmable thermostat with time and temperature control.
No real system would be wired like this, this is just an example schematic to show how 4 different zone wiring methods can be done.
The boiler is an oil boiler that requires a permanent live and a switch live to operate. The live supply from terminal 3 has been split to supply the permanent live directly, and the switch live through switch live through terminals 11-12.
F5: Clo
F6: F7:
B F8: 6 Amp
Mains
Earthing Mains OK
Earthing
Use Correct Earthing Procedures
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
On
Clock Boiler 1 Boiler 2 Mains
On
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 Pump
NL
Zone 2 Pump
NL
Zone 3 Pump
SL1 SL2 SL3 SL4
4 Channel Wireless Clock
NL
NL
Zone 4 Pump
LN
LN
Main Isolated Power Supply
Boiler Thermostat(s)
LLL
SL N PL Oil Boiler
Boiler Pump
L
N
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 6
Zone 4 – Central Heating Zone 3 – Central Heating Zone 2 – Central Heating
Zone 1 – DHW
P1
SV TN Oil Boiler
DC
Expansion Vessel
SV
LSD
TN
DHW Pressurised
DC
Zone 1 DHW
Zone 2 Heating
Zone 3 Heating
Zone 4 Heating
Figure 20: 4-zone system with a 4-channel programmer and wireless thermostats
This schematic shows an example of a 4-zone system with 1 DHW zone and 3 heating zones. The system is controlled using a 4-channel programmer and wireless thermostats. The wireless thermostats communicate directly with the programmer, which sends a switch live signal to the zones when to fire. Since these switch live signals are time and temperature controlled, they are wired directly to zone terminals A6, B6, C6 and D6. The programmer is supplied from terminals 1 and 2.
The logic would be the same for 2 and 3 zone systems, the only difference would be the number of wires from the programmer.
The boiler is an oil boiler that requires a permanent live and a switch live to operate. The live supply from terminal 3 has been split to supply the permanent live directly, and the switch live through switch live through terminals 11-12.
12
WIRING SCHEMATICS
Use Correct Earthing Procedures
F1: 1 A Zone
F2: 1 A Zone
F3: 1 A Zone
F4: 1 A Zone
F5: 3 Amp Clock
F6: 3 Amp Blr 1
F7: 3 Amp Blr 2
F8: 6 Amp Mains
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Boiler On
Clock Boiler 1 Boiler 2 Mains
Aux On
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
21 22 23 24 Aux. INPUT Live-In
Aux / Frost Power Power Supply Supply N N Aux Frost
25 26 27 28 29 30 NNL L L L
Earthing
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 6
Zone 4 – Central Heating Zone 3 – Central Heating Zone 2 – Central Heating
Zone 1 – DHW
P1
NL
Zone 1 Pump
NC C
NO C
Zone 1 Roomstat / Cylinder (Break on temp rise)
NL
Zone 2 Pump
NC C
NO C
Zone 2 Roomstat / Cylinder (Break on temp rise)
NL
Zone 3 Pump
NC C
NO C
Zone 3 Roomstat / Cylinder (Break on temp rise)
NL
Zone 4 Pump
NC C
NO C
Zone 4 Roomstat / Cylinder (Break on temp rise)
SL1 SL2 SL3 SL4
NL
4 Channel Time Clock
LN
LN
Main Isolated Power Supply
Boiler Thermostat(s)
LLL
SL N PL Oil Boiler
Boiler Pump
L
N
SV TN Oil Boiler
DC
Expansion Vessel
SV
LSD
TN
DHW Pressurised
DC
Figure 21: 4-zone system with a 4-channel programmer and wired thermostats This schematic shows an example of a 4-zone system with 1 DHW zone and 3 heating zones. The system is controlled using a 4-channel programmer and wired thermostats. The switch live signals from the programmer are time controlled so they are wired to zone terminals A4, B4, C4 and D4. The programmer is supplied from terminals 1 and 2. The thermostats then take this signal from zone terminals A5, B5, C5 and D5, and supplies it back to terminals A6, B6, C6 and D6 if they are not satisfied.
The logic would be the same for 2 and 3 zone systems, the only difference would be the number of wires from the programmer and the number of thermostats.
The boiler is an oil boiler that requires a permanent live and a switch live to operate. The live supply from terminal 3 has been split to supply the permanent live directly, and the switch live through switch live through terminals 11-12.
Use Correct Earthing Procedures
F1 Z
F2 Z
F3 Z
F4 Z
F5: 3 Cloc
F6: 3 Blr
F7: 3 Blr
F8: 6 Amp Mains
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Boiler On
Clock Boiler 1 Boiler 2 Mains
Aux On
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 Pump
NC C
NO C
Zone 1 Roomstat / Cylinder (Break on temp rise)
NL
Zone 2 CH Pump
NL
Zone 3 CH Pump
LN
LN
Main Isolated Power Supply
Gas Boiler M
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 5
Zone 3 – Central Heating Zone 2 – Central Heating Zone 1 – DHW
Expansion Vessel
SV
LSD
TN
DHW Pressurised
SL L N
SL L N
SL L N
Zone 1 Timer
Zone 2 Programmable
Roomstat
Zone 3 Programmable
Roomstat
Figure 22: 3-zone system with hot water priority
Gas Boiler
VF2
VF1
N
DC
L
Gas Boiler with a permanent live and voltage free switching.
This schematic shows how to wire a 3-zone system with hot water priority. The DHW zone has a timer and a thermostat while the heating zones have programmable thermostats. This could be any combination of timers, thermostats, programmer; the focus of this schematic is the DHW priority.
When the DHW zone is calling for heat a switch live from terminal A7 to 21 switches the auxiliary relay. This breaks the circuit for both heating zones which have the pump call circuits wired through the normally closed (NC) contacts on the auxiliary outputs. Therefore, the central heating pumps are unable to run whenever the DHW zone is calling, regardless of the central heating controls.
13
Use Correct Earthing Procedures
F5: F6: F7: F8: 6 Am Mains
WIRING SCHEMATICS
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Relay Contacts Max: 5 Amp
Earthing
27 – 30
F9: 3 Amp
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
Gas Boiler
NOG L
MV Zone 1
NC C
NO C
Zone 1 Roomstat / Cylinder (Break on temp rise)
NOG L
MV Zone 2
NC C
NO C
Zone 2 Roomstat / Cylinder (Break on temp rise)
NOG L
MV Zone 3
NC C
NO C
Zone 3 Roomstat / Cylinder (Break on temp rise)
LN
LN
Main Isolated Power Supply
M
MV
M
MV
M
MV
Expansion Vessel
M
Zone 3 – Central Heating Zone 2 – Central Heating Zone 1 – DHW
SL1 SL2 SL3
3 Channel Time Clock
NL
Gas Boiler
VF2 VF1 N
L
SV
LSD
TN
DHW Pressurised
Gas Boiler with a permanent live and
voltage free switching.
DC
Figure 23: 3-zone system with motorised valves, a 3-channel programmer and wired thermostats
This schematic shows an example of a 3-zone system with 1 DHW zone and 2 heating zones zoned using 2-port
motorised valves. The system is controlled using a 3-channel programmer and wired thermostats. The switch live
signals from the programmer are time controlled so they are wired to zone terminals A4, B4 and C4. The programmer
is supplied from terminals 1 and 2. The thermostats then take this signal from zone terminals A5, B5 and C5, and
supplies it back to terminals A6, B6 and C6 if they are not satisfied.
Once there is a live into a zone’s terminal 6, the motorised valve will open. When the valve is fully open, the internal switch will trigger and carry the switch live signal from zone terminal 9 to 10, triggering the boiler relay and running the boiler.
NOTE: In this example the boiler has an internal pump, if your system requires you to wire the circulation pump
separately, you can do this by taking a live and neutral from terminals 5 and 6. Wire the live through terminals 13 and
14, and then to the pump. This will ensure that the pump only turns on when the motorised valves have opened.
Earthing Mains OK
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
Boiler On
Clock Boiler 1 Boiler 2 Mains
Aux On
Relay Contacts Max: 5 Amp
Earthing
Use Correct Earthing Procedures
F1: Z
F2: Z
F3: Z
F4: Z
F5: 3 A Clock
F6: 3 A Blr
F7: 3 A Blr
F8: 6 Amp Mains
F9: 3 Amp 27 – 30
Earthing
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 Pump
NC C
NO C
Zone 1 Cyl Stat (Break on temp rise)
N OG L
MV Zone 2
NC C
NO C
Zone 2 Room Stat (Break on temp rise)
N OG L
MV Zone 3
NC C
NO C
Zone 3 Room Stat (Break on temp rise)
LN
LN
Main Isolated Power Supply
LN
Zone 2 & 3 Pump
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 4
Zone 1 – DHW P1
SL L N
Zone 2 Timer
SL L N
Zone 3 Timer
SL L N
Zone 4 Timer
Boiler Thermostat(s)
LLL
L N
Oil Boiler
Boiler Pump
L
N
SV TN Oil Boiler
DC
Expansion Vessel
SV
LSD
TN
DHW Pressurised
DC
MV M
Zone 2 – Central Heating
MV M
Zone 3 – Central Heating
Figure 24: 3-zone system with an individually pumped DHW zone and heating 2
heating zones zoned with motorised valves
This schematic shows how to wire a 3-zone system where the DHW zone has its
own circulation pump while the two heating zones share a circulation pump. All
three zones have individual timers and thermostats. This could be any
combination of timers, thermostats, programmer; the focus of this schematic is
the zone pump and valve controls.
The central heating circulation pump is wired through qusiiary output 1’s
normally open contacts. Whenever one of the motorised valves are open the
singal from its orange wire will fire the boiler, but also swith the auxiliary
relay through terminals 21 or 22. When the auxiliary relay switches the
central heating circulation pump runs.
Normally the common pump for motorised valve controlled zones would be wired
using the boiler relay as described above. However, in this example doing that
would run the heating pump whenever the DHW zone is running.
14
WIRING SCHEMATICS
Earthing Mains OK
Earthing
Use Correct Earthing Procedures
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
F5 F6 F7 F8: 6 Amp Mains
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NRV
AAV
NRGZone 5 ST
Main Isolated Power Supply EXT
Zone 3 – Central Heating P3
Zone 2 – Central Heating
Zone 1 – Central Heating
SL L N Zone 1 Underfloor Wiring Centre
NL
Zone 1 CH Pump (Might be wired directly from the underfloor wiring centre
instead of the NRG Lex)
SL L N Zone 2 Underfloor Wiring Centre
NL
Zone 2 CH Pump (Might be wired directly from the underfloor wiring centre
instead of the NRG Lex)
SL L N
NL
Zone 3
Zone 3
Programmable CH Pump
Roomstat
LN LN
HEAT PUMP 1 2
Heat Pump
AAV T
AAV T
1 2 3 4 5 6 7 8 9 10 11 12
P1 MX
P2 MX
12 11 10 9 8 7 6 5 4 3 2 1
AAV T AAV T
Figure 25: 3-zone system an integrated type heat pump two mixed underfloor heating zones and a radiator zone. This schematic shows an example of how to wire a 3-zone system with a heat pump that has an integrated DHW cylinder. Since the cylinder is a part of the heat pump, we don’t have to worry about the DHW side of the system as that is handled internally. We just need to supply the heat pump with a heat call, which is done through the boiler call switch terminals 11 to 12.
The zones are 2 underfloor heating zones and a radiator zone. Since the radiator zone operates at a higher
temperature than the underfloor zones, they need to have a mixing valve. The underfloor zones are controlled using
their own underfloor wiring centres. These wiring centres are usually wired to one or more room thermostats and
control the actuators for the underfloor pipe loops. The NRG Lex supplies the live to the underfloor wiring centres
from terminals A1 and B1 and receives a switch live back to terminals A6 and B6. This switch live is used to run the
zone pump and close the boiler call switch to run the heat pump. In some cases, the zone pumps are wired from the
underfloor wiring centres instead of the NRG Lex. In those cases, you can omit the pump from the NRG Lex, but you
still need the switch live to terminals A6 and B6 and loops from A9 to A10 and B9 to B10 to switch the boiler call relay.
The radiator zone is controlled with using a programmable thermostat, usually the same type of stat that is wired to
the underfloor wiring centres.
Earthing Mains OK
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
F5 F6 F7 F8: 6 Amp Mains
On
Clock Boiler 1 Boiler 2 Mains
On
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Use Correct Earthing Procedures
Earthing
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
Main Isolated Power Supply EXT
External Relay
Relay C
NC NO
Coil
L
N
NL
Zone 1 DHW Pump
SL L N Zone 2 Underfloor Wiring Centre
NL
Zone 2 CH Pump (Might be wired directly from the underfloor wiring centre
instead of the NRG Lex)
SL L N
NL
Zone 3
Zone 3
Programmable CH Pump
Roomstat
LN LN
Expansion Vessel
Optional Cold Feed / Expansion Point AAV
NRGZone 5 M
Zone 3 – Central Heating P3
Zone 2 – Central Heating
Zone 1 – DHW P1
5 16
Hot water call from heat pump
HEAT PUMP 1 2
Heat Pump
AFV AFV
SV
LSD
TN
DHW Pressurised
AAV T
AAV
1 2 3 4 5 6 7 8 9 10 11 12
P2 MX
DC
T
Figure 26: 3-zone system a monobloc heat pump, hot water priority ann underfloor heating zone and a radiator zone
This schematic shows an example of how to wire a 3-zone system with a monobloc heat pump. As is common with
heat pumps like this, there is a DHW sensor in the heat pump connected directly to the heat pump. When the heat
pump switches to DHW heating it sends out a live signal to switch an external 3-port diverter valve. Since this is a
system controlled with zone pumps there is no diverter valve. Instead, we use that switch live to turn on Zone A,
which runs the DHW zone pump and switches the auxiliary relay to break the circuit for the two heating zones. Since
the heat pump is on a different supply than the NRG Lex, as most often is the case, we must use an external relay
to control Zone A. The switch live from the heat pump switches this external relay, which makes the connection
between terminals A1 and A6. The heat pumps heat call is simpler, just using the volt free contacts on the heat pump
through the boiler call switch terminals 11 and 12.
The zones are an underfloor heating zones and a radiator zone. Since the underfloor zone operates at a lower temperature than the radiator zone, it needs to have a mixing valve. The underfloor zone is controlled using an underfloor wiring centre. The wiring centre is usually wired to one or more room thermostats and controls the actuators for the underfloor pipe loops. The NRG Lex supplies the live to the underfloor wiring centre from terminal A1 and receives a switch live back to terminal A6. This switch live is used to run the zone pump and close the boiler call switch to run the heat pump. The radiator zone is controlled with using a programmable thermostat.
15
Use Correct Earthing Procedures
F F F F8: 6 Am Mains
WIRING SCHEMATICS
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Boiler 1 Boiler 2 Mains
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 CH Pump
SL L
NO C Zone 1 DHW Stat (Break on temp Rise)
NL
Zone 2 CH Pump
SL L
NO C
Zone 2 Roomstat
CH
NL
Zone 3 CH Pump
SL L
NO C
Zone 3 Roomstat
CH
LN
LN Main Isolated Power Supply
LN
Stove Pump
Top of Expansion Maximise This Distance
Water Level
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 5
Zone 3 – Rads Zone 2 – Rads Zone 1 – DHW
L NC
DHW Cylinder
Boiler Thermostat(s)
LLL
SL1 SL2 SL3
N L
SL N PL Oil Boiler
Boiler Pump
L
N
3 Channel Time Clock
Figure 27: 3-zone system an oil boiler and a solid fuel stove. 2 solid fuel heat dump zones.
NO
Stove Stat (Make On Temp Rise)
SV TN Oil Boiler
DC
P1
INJECTOR TEE
NOTE: Heat leak radiators must be sized according to solid fuel stove
manufacturers instructions
SV TN
Solid Fuel Stove
This schematic shows the wiring for a heating system with 3 zones, an oil boiler and a solid fuel stove. Since the solid
fuel stove is an uncontrollable heat source it is important that the energy generated by the stove has somewhere to
go when it is lit. This system achieves that by having a pipe thermostat on the return to the solid fuel stove. When this
thermostat gets hot, meaning the stove is lit, the connection from terminal 27 to 21 is made through the thermostat.
This switches the auxiliary relay, but the signal also carries through from terminal 21 to 21a which in turn runs the solid
fuel pump. The solid fuel pump transfers the heat from the stoves gravity circuit to the heating system and improves
the flow rate through the stove.
The zone pumps for the two heating zones are wired through the auxiliary outputs. When the stove is cold, the
pumps are controlled by the normal zone controls through the normally closed (NC) connections. When the stove
is lit and the auxiliary relay switches, the zone controls are bypassed, and the pumps are forced to run due to the
permanent lives (terminals 28 & 29) being supplied to the normally open (NO) connections on the auxiliary output.
This ensures that the two heating zones is taking the energy away from the stove whenever it is lit.
Earthing Mains OK
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
CLOCK
STAT
LLLLLL
Clock Boiler 1 Boiler 2 Mains
F8: 6 Ma
Relay Contacts Max: 5 Amp
Earthing
F9: 3 Amp 27 – 30
Use Correct Earthing Procedures
Earthing
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 CH Pump
SL L
NO C Zone 1 DHW Stat (Break on temp Rise)
NL
Zone 2 CH Pump
SL L
NO C
Zone 2 Roomstat
CH
NL
Zone 3 CH Pump
SL L
NO C
Zone 3 Roomstat
CH
LN
LN Main Isolated Power Supply
LN
Stove Pump
Top of Expansion Maximise This Distance
Water Level
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 5
Zone 3 – Rads Zone 2 – Rads Zone 1 – DHW
Boiler Thermostat(s)
LLL
L NC
DHW Cylinder
SL1 SL2 SL3
N L
SL N PL Oil Boiler
Boiler Pump
L
N
NO
Stove Stat (Make On Temp Rise)
3 Channel Time Clock
SV
TN
Oil Boiler
Figure 28: 3-zone system an oil boiler and a solid fuel stove. 1 solid fuel heat dump zone and boiler break
DC
P1
INJECTOR TEE
NOTE: Heat leak radiators must be sized according to solid fuel stove
manufacturers instructions
SV TN
Solid Fuel Stove
This schematic shows the wiring for a heating system with 3 zones, an oil boiler and a solid fuel stove. Since the solid
fuel stove is an uncontrollable heat source it is important that the energy generated by the stove has somewhere to
go when it is lit. This system achieves that by having a pipe thermostat on the return to the solid fuel stove. When this
thermostat gets hot, meaning the stove is lit, the connection from terminal 27 to 21 is made through the thermostat.
This switches the auxiliary relay, but the signal also carries through from terminal 21 to 21a which in turn runs the solid
fuel pump. The solid fuel pump transfers the heat from the stoves gravity circuit to the heating system and improves
the flow rate through the stove.
The oil boiler is wired through the normally closed (NC) contacts on Auxiliary Output 1. This means that when the stove is lit and the auxiliary relay switches, the boiler circuit is broken. This prevents the boiler from firing when the stove is lit and eliminates the oil usage. There is also a live wire from terminal 28 through the normally open contacts (NO) of Auxiliary Output 2 that goes to terminal C7. When the stove is lit and the auxiliary relay closes, this circuit is made and a switch live is supplied to terminal C7, running Zone C’s pump to make Zone C the heat dump zone for the stove. The remaining zones continue working as usual using their time and temperature controls.
16
WIRING SCHEMATICS
Use Correct Earthing Procedures
F5: F6: F7: F8: 6 Amp Mains F9: 3 Amp 27 – 30
Earthing Mains OK
Earthing
CLOCK
STAT
LLLLLL
A1 A2 A3 A4 A5 A6
ZONE A
N N Blr Call L L A12 A11 A10 A9 A8 A7
CLOCK
STAT
LLLLLL
B1 B2 B3 B4 B5 B6
ZONE B
N N Blr Call L L B12 B11 B10 B9 B8 B7
CLOCK
STAT
LLLLLL
C1 C2 C3 C4 C5 C6
ZONE C
N N Blr Call L L C12 C11 C10 C9 C8 C7
CLOCK
STAT
LLLLLL
D1 D2 D3 D4 D5 D6
ZONE D
N N Blr Call L L D12 D11 D10 D9 D8 D7
On
Clock Boiler 1 Boiler 2 Mains
On
Relay Contacts Max: 5 Amp
Earthing
Clock Power
Boiler 1 Boiler 2 Power Power
1
2
Mains Power Input
LNLNLNLN
12345678 Clock Blr 1 Blr 2 Mains
Extra Frost Boiler Input
9 10
LN
1 11 12
2 13 14
9 10 11 12 13 14 Frost Blr 1 Blr 2
Auxillary Output 1
NC NO
Auxillary Output 2
NO NC
15 16 17 18 19 20 NC1 COM1 NO1 NO2 COM2 NC2
Aux. OUTPUT Live-In 21a 22a 23a 24a
Aux / Frost
Power Power Supply Supply N N Aux Frost
21 22 23 24 Aux. INPUT Live-In
25 26 27 28 29 30 NNL L L L
Earthing
NL
Zone 1 DHW Pump
Break on Temp Rise
NL
Zone 2 CH Pump
NC C
NO C
Zone 2 Room Stat (Break on temp rise)
NL
Zone 3 CH Pump
NC C
NO C
Zone 3 Room Stat (Break on temp rise)
LN
LN
Main Isolated Power Supply
NC L
NO C DHW Stat
Make on Temp Rise
Gas Boiler
PL SL1 SL2 SL3
N
SL
N L
3 Channel Time Clock
Gas Boiler with a permanent live and switch live.
Figure 29: Interlinked sealed and open vented heating systems with solid fuel stove, gas boiler & 3 zones
Gas Boiler M
Sealed System
NRV
Optional Cold Feed / Expansion Point
AAV
NRGZone 5
Zone 3 – Central Heating Zone 2 – Central Heating Zone 1 – DHW
Expansion Vessel
SV
LSD
TN
DHW Pressurised
DC
NRGLink PHE
Open System
ST
NOTE:
Heat leak radiators must be sized according to solid fuel stove manufacturers
instructions
SV TN
Solid Fuel Stove
L N
E NRGLink
SL
This schematic shows the wiring of a 3-zone sealed gas boiler system interconnected with an open vented solid fuel stove. The interlinking is done using an NRG Link by NRG Awareness. There is a live and neutral supply to the NRG Link from terminals 26 and 27. There is also a switch live wire coming from the NRG Link to terminal 21 on the NRG Lex. Whenever the stove is lit, the NRG Link will activate using an internal thermostat. This will run the pumps in the NRG Link to transfer the heat to the sealed heating system. It will also send a live signal to terminal 21 to switch the auxiliary relay.
The zones here are wired using a 3-channel programmer and individual wired thermostats. In this example Zone A and Zone B are heat leaks, however since zone A is a DHW zone it cannot be considered a “true” heat leak as there is a limit to how hot you want the DHW cylinder to become. Therefore, the system is wired so that Zone A is the first heat leak, when Zone A is satisfied, Zone B takes over as the heat leak. This is achieved by joining the input to the DHW thermostat with the normally open (NO) contact of Auxiliary Output 1 and the normally open (make on temperature rise) connection of the DHW thermostat to the common (C) connection of Auxiliary Output 2. The normally open (NO) connection on Auxiliary Output 2 is connected to Zone 2 for it to act as the second heat dump.
When the NRG Link activates, the auxiliary relay switches. This breaks the boiler circuit (wired through the Auxiliary Output 1 normally closed contact), preventing the boiler from calling. The permanent live that would usually go to the boiler from terminal 3 now get supplied to the DHW thermostat through the normally open contact. This will force the DHW pump to run until the DHW stat is satisfied. Once the DHW stat is satisfied the signal goes through the stat’s normally open contact, through Auxiliary Output 2, and over to terminal B7 to run Zone B’s pump. The reason for going through Auxiliary Output 2 and not directly from the DHW stat to B7 is to prevent any back-feed between the zones when the solid fuel stove is off.
The schematics above just shows some examples of systems wired using the NRG Lex 2.1. For more system examples see www.nrgawareness.com/schematics or scan the QR code below.
SKETCH HERE
9. System Sketchpad with NRG Lex v2.1
Draw your own system here
CONTACT
+353 214 355728 [email protected] nrgawareness.com shop.nrgawareness.com
SEA BOX Energy T/A NRG Awareness Brooklodge East, Glanmire, Co. Cork, Ireland,
T45 Y018
SEA BOX Energy is a part of SeaBox Group
References
- NRG Awareness
- NRG Awareness - Core Products by NRG Awareness
- NRG Resource Hub | Free Schematics Database