Hotstart HE High Efficiency Heating System Instruction Manual

: June 13, 2024
: HOTSTART

Table of Contents

HE High Efficiency Heating System
HE Functional Specifications
Lockout Switch
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HE High Efficiency Heating System

Installation and Operation Manual

HE

High Efficiency
Heating System

HS.HOTSTART.COM/HOTSTART-HEATPUMPS

DISCLAIMER: This system has been designed and manufactured
EXCLUSIVELY to heat diesel engine emergency generators. It is not
authorized for any other use.

HE Heating System Indentification

1. Air Discharge
2. Air Filter/Air Coil
3. Blower Motor and Condensate Pan Access
4. Three-way Toggle Switch
5. Run Hour Meter
6. Status Light
7. Electrical Knockouts
8. Electrical Controls
9. Water Outlet (hot)
10. Condensate
11. Water Inlet (cold)

Site Pre-Requisites

HE heat pump is approximately 22” wide by 22” deep
by 45” tall
You will need at least 6” clearance from the air filter to
any wall
If installing outdoors you will need a dog house shelter
for the unit
Unit is 208/230 volts single phase
Condensate may be drained via gravity feed. If not the
use of a Little Giant condensate pump Model VCMA10
208 volts may be used.
Please keep unit off the floor via rubber isolation pads
or condensing pad

Safety Precautions

Turn power off to breaker for both engine heaters and
HE heat pump.
Close hydraulic coolant line ball valves to and from
engine heaters
Install hydraulic lines from HE to engine heater
Install electrical conduit and wiring to and from HE
heat pump.
Once electrical and hydraulic installation is complete
turn on ball valves and electrical power to unit

General Hydraulic Parts List (Not included)

HYDRAULIC PARTS – 1 ENGINE HEATER

HE-12 model heat pump:

• Flex Fab Silicone Heater Hose ¾” QTY: 30’
• Brass Hose Barbs ¾” x ½” (male)” QTY: 10
• Sleeved Constant Torque Hose Clamps QTY: 4
• Brass Hose Barb ½” x ½” (male) QTY: 1
• Rubber Isolation Pads QTY: 4
• Teflon Pipe Thread Sealant

Flex Fab Silicone Heater Hose ¾” (30’ or 60’ length)

HYDRAULIC PARTS – 1 ENGINE HEATER

HE-18 or HE-24 model heat pump:

• Flex Fab Silicone Heater Hose ¾” QTY: 30’
• Brass Hose Barbs ¾” x ¾” (male)” QTY: 4
• Sleeved Constant Torque Hose Clamps QTY: 4
• Brass Hose Barb ½” x ¾” (male) QTY: 1
• Rubber Isolation Pads QTY: 4
• Teflon Pipe Thread Sealant

Brass Barbs to Male Hose (¾” x ½”), (½” x ½”), (¾” x ¾”)

HYDRAULIC PARTS – 2 ENGINE HEATERS

HE-12 model heat pump:

• Flex Fab Silicone Heater Hose ¾” QTY: 60’
• Brass Hose Barbs ¾” x ½” (male)” QTY: 10
• Sleeved Constant Torque Hose Clamps QTY: 10
• Brass Hose Barb ½” x ¾” (male) QTY: 1
• Rubber Isolation Pads QTY: 4
• Brass Tee ¾” QTY: 2
• Teflon Pipe Thread Sealant

Sleeved Constant Torque Hose Clamps

HYDRAULIC PARTS – 2 ENGINE HEATERS

HE-18 or HE-24 model heat pumps:

• Flex Fab Silicone Heater Hose ¾” QTY: 60’
• Brass Hose Barbs ¾” x ¾” (male)” QTY: 10
• Sleeved Constant Torque Hose Clamps QTY: 10
• Brass Hose Barb ½” x ½” (male) QTY: 1
• Rubber Isolation Pads QTY: 4
• Brass Tee ¾” QTY: 2
• Teflon Pipe Thread Sealant

Rubber Isolation Pads

Tools Needed (Not included)

• Adjustable Cresent Wrench QTY: 2
• Nut Driver 5/16”
• Flat Head Screwdriver

Brass Tee (¾”)

Teflon Pipe Thread Sealant

Tools: Crescent Wrench, Nut Driver & Screwdriver

Hydraulic Installation Procedure

HYDRAULIC INSTALLATION – 1 ENGINE HEATER

Remove inlet line from engine block to existing engine
heater.
Install 3/4” hose barbs at HE Gen HP inlet, outlet
and condensate (top outlet and bottom inlet fittings).
Middle fitting is condensate. Use small amount of
Teflon paste on male pipe threads. Do not over tighten
hose barb fitting to HE Gen HP brass pipe fitting.
From engine block attach silicone heater hose and run
to HE Gen HP inlet hose barb. Secure hose with hose
clamps.
From HE outlet hose barb install silicone hose and
hose clamp. Then run silicone hose to engine heater
inlet.
Install ¾” male by ½” barb at the condensate fitting HE
Gen HP (middle fitting that is plastic).
COMPLETE ELECTRICAL INSTALLATION (pg 6)
Do not open ball valves till electric installation has
been completed. You should then open only the inlet
ball valve. Turn on power to HE Gen HP. Once turned
on, open the outlet ball valve to purge air from the
heating system.
Normally 20 feet of silicone heater hose will be used, 4
qty ¾” hose barbs and 4 qty hose clamps are used.
Place plastic condenser pad under HE Gen HP along
with rubber isolation pads to keep moisture off the
bottom of the HE Gen HP.

A single engine heater system can be installed in about 1 to 3 hours.

Hydraulic Installation Procedure

HYDRAULIC INSTALLATION – 2 ENGINE HEATERS

Follow instructions above. Start by removing the inlet
lines to both engine heaters from the engine to the
inlet of the engine heaters.
You will need two TEE fittings with ¾” hose barbs
installed on all three fittings of the TEE. Small amount
of Teflon paste is recommended on all male thread
fittings.
The TEE fitting should be installed as close as possible
to the engine and/or one of the engine heaters. You
can run a single inlet and outlet silicone heater hose
from the HE Gen HP to the TEE fittings.
From the TEE fitting, one fitting will be for your inlet
and you will run silicone heater hose to both sides of
the engine inlets. Then from the outlet TEE you will
run silicone heater hose to both sides of the engine
connecting to the engine heater inlet.
Install ¾” male by ½” barb at the condensate fitting HE
Gen HP (middle fitting that is plastic).
COMPLETE ELECTRICAL INSTALLATION (pg 6)
Do not open ball valves till electric installation has
been completed. You should then open only the inlet
ball valves. Turn on power to HE Gen HP. Once turned
on, open the outlet ball valve to purge air from the
heating system.
The installation parts for 2 engine heaters will be 40
feet of silicone hose, 10 qty of ¾” hose barbs and 10
qty hose clamps (see pictures from list of materials).
Place plastic condenser pad under HE Gen HP along
with rubber isolation pads to keep moisture off the
bottom of the HE Gen HP.

A two engine heater system can be installed in about
2 to 5 hours.

Electrical Parts List

Liquid Tight Flex Conduit; length 20’

Liquid Tight Conduit Fittings Elbow (90°); QTY 2

Wire 30’ (2 hots and 1 ground)

HE Heating System Electrical Installation

HE heat pump has a 40 amp contactor to power the
existing engine heater.
Units are 208/230 volt single phase
HE heat pump can be powered by a 20 amp service or
by using existing engine heater that is 40 amps or less.
Ranco two stage thermostat ensure an either/
or operation where by only the HE heat pump can
operate or the existing engine heaters – not both at the same time.
3 way toggle switch should be set to the bottom
position “HP & Electric heat”. Middle position is off
(power still is on inside the HE heat pump) and up
“Electric Heat” is engine heater only.

Electrical Identification

1. L1
2. L2
3. EHC Engine Heater Contact
4. Ranco Temerature Control

Ranco Temperature Controls

Press the set button
to adjust set points
S1: Heat Pump
S2: Engine Heater

HE Heating System Wire Diagram

NOTES:
1. Compressor and Blower Motor thermally protected internally.
2. All wiring to the unit must comply with NEC and local codes, low voltage wiring shall be
Class 2 or equivalent.
3. Transformer wiring is voltage sensitive. Use layout corresponding to the unit voltage.
4. LTI provides low temperature protection for WATER. When using ANTI-FREEZE solutions, cut
JW3 jumper.
5. Typical heat pump thermostat wiring shown. Refer to thermostat IOM for wiring to the unit.
T-Stat wiring must be Class 1 and voltage rating equal to or greater than unit supply voltage.
6. 24V Alarm signal shown. For Dry Alarm contact between AL1 & AL2, cut JWI for CXM/DXM
Gen2 or JW4 DXM.
7. Transformer Secondary Ground via control board standoffs and/or Common to Control Box.

BM4 Blower motor factory wired to Medium speed. For Low speed remove BLU wire from
Medium tap and connect to Low Speed Tap. For High speed remove BLU wire from
existing Speed Tap and remove BRN jumper wire from High Speed Tap. Connect BLU wire
to High Speed Tap. Tape off Unconnected end of BRN jumper.
HWG3 WSTAT is supplied with unit and must be wired in series with the hot leg to the pump.
WSTAT is rated for voltage up to 277V.
SAC1 Use start assist capacitor only on unit size 006-012.

ACO Automatic Change Over
AL Alarm Relay Contacts
ATS Air Temperature Sensor
BM Blower Motor
BMC Blower Motor Capacitor
BR Blower Relay/Blower Contactor
CAP Capacitor
CB Circuit Breaker
CC Compressor Contactor
CDT Compressor Discharge Temperature
CO Condensate Overflow Sensor
CR Compressor Relay
CRC Compressor Run Capacitor
CS Current Sensor
DHW Domestic Hot Water
DM Damper Motor
DTS Discharge Temperature Switch
EEV Electronic Expansion Valve

EHC Electronic Heat Contactor
ES End Switch
ETC Electronic Temperature Control
EWT Entering Water Temp Sensor
FSR Fan Speed Relay
FSS Fan Speed Switch
HP High Pressure Switch
HPWS High Pressure Water Switch
HR Heating Relay
JW Jumper Wire
LAT Leaving Air Temperature
LOR Lock Out Relay
LP Low Pressure Switch
LT1 Sensor, low temp protection, water coil
LT2 Sensor, low temp protection, air coil
LWT Leaving Water Temp Sensor
MCO Manual Change Over
MOD Modulating Water Valve

MS Manual Starter
MSC Multi-Splice Connector
MWV Motorized Water Valve
NLL Night Low Limit Switch
PDB Power Ditribution Block
POT Potentionmeter
P1 Field Wiring Terminal Block
PR Pump Relay
RAS Return Air Sensor
RVS Reversing Valve Solenoid
SAC Start Assist Capacitor
SAS Supply Air Sensor
TB Terminal Block
TRANS Transformer
UMT Unit Mounted Thermostat
VFD Variable Frequency Drive
VSP Variable Speed Pump
WSTAT Water Stat

Sequence of Operations

This sequence of operation is for information purposes
only. Once the heat pump has been set up there should
be no further action required by the customer related to
operational function or changing of any set points.
The heat pump system requires approximately 40-70%
operation in order to maintain the designed temperatures,
vs the typical engine heater operation of 50-100%. The
system will automatically shut off if outside air temperature
drops to approximately 40 oF (5 oC), or supply voltage
drops to 197V or over 250V. In either condition, the engine
heater will automatically resume operation based on the
control of the dual stage thermostat. As soon as either of
those conditions are corrected, the heat pump will resume
operation and continue unless the above conditions
persist.

There is a three-way switch on the unit
for bypass, off, and dual mode. The
dual mode Comp/EH mode is the down
position and the only operating mode
unless troubleshooting the heat pump
is required. The green status light will
advise of a fault code and a steady green
advises that the heat pump is operating
to specification. A flashing green
indicates a fault has occurred. Neither
up nor down is the off position. The up
position is for engine heater only mode

HE 3-Way Toggle Switch Operation

EH: Engine Heater On
OFF: Both systems off
COMP/EH: HE Heat Pump On
Heat Pump primary heat source
with Engine Heaters as back up

HE Heating System Operation & Maintenance

The Hotstart HE Heating System provides energy
savings while providing a redundant heating source for
the engine. Hydraulic tubing is routed in series through
the existing engine heater(s), making the heat pump
the primary heating source. This is controlled by a dual
stage thermostat, which insures the system operates with
redundancy. Should the heat pump ever fail to maintain
a minimum temperature of 94 oF (34 oC), the engine
heater(s) will engage and raise the coolant temperature
until the heat pump can safely maintain the targeted
temperature range.

Operating instructions:

Heat pump switch should be left in the “Comp & EH” mode
so that the heat pump is the primary heat source and
engine heater is set as back-up (photo#31).
To check heat pump operation remove front panel. The
light on the control board should be a steady green. A
flashing green light indicates failure.
In a case of heat pump failure, turn switch to “EH” (engine
heater) position. If there is a fast or slow flash refer to
manual for troubleshooting guide.
Middle position on the switch turns both heaters off. Do
not select unless specific maintenance is required. When
finished, return the system to “Comp & EH” mode.

Thermostat:

Press “set” button to scroll settings
S1 = Heat Pump, S2 = Engine Heater(s)
Settings: F or C: set to “F” (Fahrenheit)
S1: 100 oF (40 oC), Diff 5 oF, H1 or C1 (H1 for heat)
S2: 95 oF, Diff 5 oF, H2 or C2 (H2 for heat)

Other Notes:

Heat pump and engine heaters will not be running
simultaneously.
HE heat pump does not have a defrost cycle – it shuts
off when air temperature is below 40 oF (5 oC).
Thermostat senses when generator is running,
preventing heat pump operation.
HE heat pump has copper piping that allows it to
withstand high coolant temperatures when generator
runs.
Do not use gauges on compressor unless absolutely
needed.

Maintenance:

• HE heat pump requires bi-annual maintenance, as
detailed in “Planned Maintenance”

Planned Maintenance

Our maintenance plan makes it easy to keep your
HE ASHP running at its best, ensuring it gets the
recommended scheduled maintenance.

Recommended scheduled maintenance every 6 months:

Replace air filter every 6 months (every 3 months if dirty)
Record temperature on thermostat every 6 months
Brush, vacuum, or light pressure water pump sprayer
to clean coils if needed
Check compressor amp. draw every 6 months
Record hours run every 6 months
Once on site, the above procedure should take no more
than 15 minutes to perform. Be sure to record all the
results on the log sheet and set your next maintenance
schedule for 6 months ahead.

HE Functional Specifications

Specifications

Heat Pump Model HE-12
Heating Capacity 19,800 BTU/Hr
Cooling Capacity 15,200 BTU/Hr
Voltage 208/230 phase I
Circuit Ampacity 10 AMP
Amps 5
Power Consumption 1.4 KW/Hr
EER 14.0
COP 4.1*
Dimensions (DxWxH) 22” x 17” x 43”
Weight 160lbs

Heat Pump Model HE-18
Heating Capacity 23,000 BTU/Hr
Cooling Capacity 18,600 BTU/Hr
Voltage 208/230 phase I
Circuit Ampacity 15 AMP
Amps 7.5
Power Consumption 2.1 KW/Hr
EER 11.6
COP 3.4*
Dimensions (DxWxH) 22” x 25” x 48”
Weight 200lbs

Heat Pump Model HE-24
Heating Capacity 30,000 BTU/Hr
Cooling Capacity 25,000 BTU/Hr
Voltage 208/230 phase I
Circuit Ampacity 15 AMP
Amps 12.2
Power Consumption 2.5 KW/Hr
EER 12.9
COP 3.8
Dimensions (DxWxH) 25.6” x 22.4” x 48.5”
Weight 250lbs
90 °F entering air and 100 °F entering water

HE Heat Pump vs Resistance Heaters

Annual Operating Costs

HE Heat Pump 60% run time and resistance heaters at 70% run time.

How it works

Heat Pump technology takes available heat out
of the air and transfers it efficiently to the engine
coolant system by using refrigerant under
pressure.

INSTALLATION DATA

ETC TWO STAGE ELECTRONIC
TEMPERATURE CONTROL

The Ranco® ETC is a microprocessor
based family of electronic temperature
controls, designed to provide on/off
control for commercial heating, cooling,
air conditioning and refrigeration. The ETC
is equipped with a liquid crystal display
(LCD) that provides a constant readout
of the sensed temperature, and a touch
keypad that allows the user to easily and
accurately select the setpoint temperature,
differential and heating/cooling mode
of the operation. Models are available
that operate on either line voltage
(120/208/240V AC) or low voltage (24V AC).

APPLICATIONS

With its wide temperature setpoint range
and selectable heating or cooling modes,
the ETC can be used for a wide variety of
applications including multiple compressor
control, two stage heating, ventilation
control, automatic changeover, condenser
fan cycling, space and return air temperature
control, water cooled condensers and
control with alarm function.

FEATURES

• Wide setpoint temperature range (-30°F to 220°F) and differential
adjustment (1°F to 30°F)
• Simple keypad programming of setpoint temperature, differential and
cooling/heating modes
• Two individually programmable stages for heating and/or cooling
• LCD display readout of sensor temperature, control settings, relay
status and onboard diagnostics
• LED (Light Emitting Diode) backlight to improve visibility of the display
in low light ambient applications.
• I P67 rated (water and dust resistant) thermistor-based probe to
remotely monitor temperature
• The sensor probe can be retrofitted in the field by the use of factory
installed interconnect
• Remote temperature sensing up to 400 feet
• Two SPDT output relays
• User-selectable Fahrenheit/Celsius scales
• Lockout switch to prevent tampering by unauthorized personnel
• Choice of line voltage and low voltage models available
• Optional 0 to 10 volt analog output available for remote temperature
indication
• Anti-short Cycle Compressor Delay for cooling applications

SPECIFICATIONS

Input Voltage 120 or 208/240V AC (24V AC optional), 50/60 Hz
Temperature Range -30°F to 220°F
Differential Range 1°F to 30°F
Switch Action SPDT
Sensor Thermistor, 1.94 in. long x 0.25 in. diameter
with 8 ft. cable, IP67 rated
Power Consumption 120/208/240V AC: 100 milliamps
24V AC: 2-6V AC

Relay Electrical Ratings
NO Contact 120V 208/240V
Full-load amps 9.8 Amps 4.9 Amps
Locked rotor amps 58.8 Amps 29.4 Amps
Resistive amps 9.8 Amps 4.9 Amps
Horsepower 1/2 HP 1/2 HP
NC Contact
Full-load amps 5.8 Amps 2.9 Amps
Locked rotor amps 34.8 Amps 17.4 Amps
Resistive amps 5.8 Amps 2.9 Amps
Horsepower 1/4 HP 1/4 HP
Pilot Duty: 125 VA at 120/208/240 VAC
Control Ambient Temperature
Operating -20°F to 140°F (-29°C to 60°C)
Storage -40°F to 176°F (-40°C to 80°C)
Ambient Humidity 0 to 95%, RH, Non-condensing
0 to 10V Output Impedance 1 K
Enclosure NEMA 1, Plastic
Agency Approvals UL Listed, File E94419, Guide XAPX
CSA Certified, File LR68340, Class 4813 02

ETC ORDERING INFORMATION

Uni-Line OEM Input No. of 0 – 10 V
Numbers Numbers Voltage Stages Output
ETC-211000-000 ETC-211020-000 120/240 2 No
ETC-211100-000 ETC-211120-000 120/240 2 Yes
ETC-212000-000 ETC-212020-000 24 2 No
ETC-212100-000 ETC-212120-000 24 2 Yes

OPERATION

Liquid Crystal Display (LCD)
The LCD display provides a constant readout of the sensor temperature
and indicates if either of the two output relays is energized. When the
S1 annunciator is constantly illuminated during operation, the Stage 1
relay is energized. Likewise, when the S2 annunciator is constantly
illuminated during operation, the Stage 2 relay is energized. The display
is also used with the keypad to allow the user to adjust the setpoint
temperatures, differentials and heating/cooling modes for each stage.

Backlight
When any mode key is pressed, the backlight is activated and the ETC is
in control mode. Press the SET key to begin program mode.

Control Setup
The temperature setpoint refers to the temperature at which the
normally open (NO) contacts of the output relay will open. Determine
the loads to be controlled and the operating modes required for each
stage, cooling or heating.

When the cooling mode is chosen, the differential is above the setpoint.
The relay will de-energize as the temperature falls to the setpoint.
Anti-short Cycle Compressor Delay for cooling. After a relay
de-energizes, the ETC will prevent the relay from turning on until a
configurable time has occurred to protect compressor.
When the heating mode is chosen, the differential is below the setpoint.
The relay will de-energize as the temperature rises to the setpoint.
The ETC two stage control can be set up for two stages of heating, two
stages of cooling or one stage cooling plus one stage heating. Refer to
Figures 1, 2 and 3 for a visual representations of different control setups.

Figure 3: One Stage Cooling and One Stage Heating Exampl

Programming Steps and Display Mode

The ETC two stage can be programmed in seven simple steps using the
LCD display and the three keys on the face of the control.
Step 1 To start programming, press the SET key once to access the
Fahrenheit/Celsius mode. The display will show the current
status, either F for degrees Fahrenheit or C for degrees
Celsius. Then press either the up Ç or down È arrow key
to toggle between the F or C designation.
Stage 1
Step 2 Press the SET key again to access the stage 1 setpoint. The
LCD will display the current setpoint and the S1 annunciator
will be blinking on and off to indicate that the control is in the
setpoint mode. Then press either the up Ç key to increase
or the down È key to decrease the setpoint to the desired
temperature.

Step 3 Press the SET key again to access the stage 1 differential.
The LCD will display the current differential and the DIF 1
annunciator will be blinking on and off to indicate that the
control is in the differential mode. Then press either the
up Ç key to increase or the down È key to decrease the
differential to the desired setting.
Step 4 Press the SET key again to access the stage 1 cooling or heating
mode. The LCD will display the current mode, either C1 for
cooling or H1 for heating. Then press either the up Ç or
down È key to toggle between the C1 or H1 designation.
Step 5 Press the SET key again to access the Anti-short Cycle
Compressor Delay when in Cooling Mode. Press the up Ç or
down È keys to set the delay from 1 to 20 minutes. Press
SET key again to finish the programming.
Stage 2
Step 6 Press the SET key again to access the stage 2 setpoint. The
LCD will display the current setpoint and the S2 annunciator
will be blinking on and off to indicate that the control is in the
setpoint mode. Then press either the up Ç key to increase
or the down È key to decrease the setpoint to the desired
temperature.
Step 7 Press the SET key again to access the stage 2 differential.
The LCD will display the current differential and the DIF 2
annunciator will be blinking on and off to indicate that the
control is in the differential mode. Then press either the
up Ç key to increase or the down È key to decrease the
differential to the desired setting.
Step 8 Press the SET key again to access the stage 2 cooling or heating
mode. The LCD will display the current mode, either C2 for
cooling or H2 for heating. Then press either the up Ç or
down È key to toggle between the C2 or H2 designation.
Press the SET key once more and programming is complete.
Step 9 Press the SET key again to access the Anti-short Cycle
Compressor Delay when in Cooling Mode. Press the up Ç or
down È keys to set the delay from 1 to 20 minutes. Press
SET key again to finish the programming.

Refer to Page 3 for an illustrated guide to programming the ETC.
NOTE: The ETC will automatically end programming if no keys are
depressed for a period of thirty seconds. Any settings that have
been input to the control will be accepted at that point.
All control settings are retained in non-volatile memory if power to
ETC is interrupted for any reason. Re-programming is not necessary
after power outages or disconnects unless different control settings
are required.

Lockout Switch

The ETC is provided with a lockout switch to prevent tampering by
unauthorized personnel. When placed in the LOCK position, the keypad
is disabled and no changes to the settings can be made. When placed
in the UNLOCK position, the keypad will function normally.
To access the lockout switch, disconnect the power supply and open
the control. The switch is located on the inside cover about 2 inches
above the bottom. (see Figure 4). To disable the keypad, slide the
switch to the left LOCK position. To enable the keypad, slide the switch
to the right UNLOCK position. All ETC controls are shipped with this
switch in the UNLOCK position.

Program Mode Displays

TROUBLESHOOTING ERROR MESSAGES

Display Messages
E1 Appears when either the up Ç or down È key is pressed when not
in the programming mode.
To correct: If the E1 message appears even when no keys are being
pressed, replace the control.
E2 Appears if the control settings are not properly stored in memory.
To correct: Check all settings and correct if necessary.
EP Appears when the probe is open, shorted or sensing a temperature
that is out of range.
To correct: Check to see if the sensed temperature is out of range.
If not, check for probe damage by comparing it to a known
ambient temperature between -30°F and 220°F. Replace the
probe if necessary.
EE Appears if the EEPROM data has been corrupted.
To correct: This condition cannot be field repaired.
Replace the control.
CL Appears if calibration mode has been entered.
To correct: Remove power to the control for at least five seconds.
Reapply power. If the CL message still appears, replace the control.
Normal Operating Mode
Probe Temperature °F
Relay 1 ON S1
Relay 2 ON S2
*Note Cd alternates with temperature and relay

Figure 4: Lockout Switch

INSTALLATION INSTRUCTIONS

WARNING

Electrical Shock Hazard – Turn off power at the main
power source before installing the ETC control.
DO NOT restore electrical power to the unit until the
ETC control is properly installed and cover assembled.
Fire Hazard – DO NOT locate the ETC control in an
explosive atmosphere as a fire could result due to
possible spark generation in the control.
All ETC Controls are designed as temperature controls
and are not used as temperature limit controls.
Where failure or malfunction of the ETC control could
cause personal injury or property damage, other
devices (limit or safety controls) or systems (alarm
or supervisory) intended to warn or protect against
failure or malfunction of the ETC control must
be installed.

CAUTION
Read all of the information in these instructions before installing
or operating the ETC control.
The schematic drawings and other information included in these
installation instructions are for the purpose of illustration and
general reference only.
ETC controls are not to be located in areas of significant moisture,
dirt or dust as use of the control in such environment may cause
personal injury or property damage and is likely to shorten the
control life.
It is the responsibility of the installer and the user to assure
that the application and use of the ETC control is in compliance
with all applicable federal, state, and local laws, regulations and
ordinances, including, without any limitation, all requirements
imposed under the National Electric Code and any applicable
building codes.

CONTROL MOUNTING

Mount the ETC to a wall or any flat surface using a combination of any
two or more of the slotted holes located on the back of the control
case. The control’s components are not position sensitive, but should
be mounted so that they can be easily wired and adjusted. Avoid
excessive conditions of moisture, dirt, dust and corrosive atmosphere.
The ETC has provisions for 1/2 inch conduit connections. The conduit
hub should be secured to the conduit before securing the hub to the
plastic housing of the control. When using the conduit entry in the rear
of the case, a standard plug should be inserted into the conduit hole
in the bottom. Caution should be exercised not to damage the control
circuit board or wiring when installing a conduit connector

ANTI-SHORT CYCLE COMPRESSOR DELAY

When the unit is configured for cooling and there is a call for cooling,
the relay will not activate until the Anti-short Cycle Compressor
Delay is satisfied. During an Anti-short Cycle Compressor Delay, the
temperature will alternate with Cd to indicate the Relay On is delayed.
If Relay 1 is in Anti-short Cycle Compressor Delay, the temperature will
alternate with aCd or S1 icon. If Relay 2 is in Anti-short Cycle Compressor
Delay mode, the temperature will alternate with a Cd or S2 icon.

Figure 5: Dimensions (Inches)

CONTROL WIRING

General
• All wiring should conform to the National Electric Code and local
regulations.
• The total electrical load must not exceed the maximum rating of the
control (see Specifications).
• Use copper conductors only.
• Electrical leads should not be taut; allow slack for temperature
change and vibration.

Input and Output Wiring
For typical wiring diagrams, refer to Figures 6 and 7. All connections are
made to the power (lower) circuit board. When using the 24V AC
powered models, the 24V AC input lines must enter through the
sidewall of the case. Refer to Figure 5 for location of the entry hole.

Analog Output
ETC models are available with an optional 0 to 10 volt analog output.
This signal is a linear representation of the sensor temperature with
0 volts = -30°F and 10 volts = 220°F. See figure 8 for wiring information
and Figure 5 for location of the entry hole. The reference for this output
is designated by the ”-” symbol on the wiring diagram. The output
signal is designated by the ”+” symbol.

FIELD REPAIRS
Field calibrating or repairs to the ETC control must not be attempted.
Sensors and replacement controls are available through Ranco
wholesalers.

SENSOR MOUNTING
For space sensing, mount the sensor where it will be unaffected by
heat/cool discharge or radiated heat sources. Spot sensing requires the
sensor to be in good contact with the surface being sensed. The sensor
can be inserted in a bulb well for immersion sensing

EXTENDING SENSOR
CAUTION: Sensor wiring splices may be made external from the control.
CAUTION: Disconnect power to control before wiring to avoid possible
electrical shock or damage to the controller.
Additional cable can be spliced to the sensor cable to increase the
length beyond the standard 8 feet. It can be extended up to 400 feet.
The cable should be at least 22 AWG or larger to keep additional
resistance to a minimum.
All splices and wire lengths added to the sensor cable should be made
according to acceptable wiring practices and should conform to the
National Electrical Code and local regulations. Use copper conductors
only. Shielded cable is not required. The sensor is not polarity sensitive.

Checkout Procedure
1. Before applying power, make sure installation and wiring
connections are correct.
2. Apply power to the control and observe one or more cycles
of operation.
3. If performance indicates a problem, check sensor resistance
to determine if sensor or control is at fault.
4. To check sensor resistance, disconnect sensor and measure
the resistance across the leads while measuring temperature
at the sensor

SENSOR REPLACEMENT

Figure 9: Sensor replacement on Display (Upper) Circuit Board.

Sensor Replacement

ETC models are available with Quick Connect Sensor feature that
allows for easy sensor replacement due to damage or wear. To access
the sensor connector, disconnect the power supply and open the
control. Remove single screw located in the center of the Display
Upper Circuit Board and carefully remove Display Board Circuit.
Remove Sensor Strain Relief to allow sensor to be removed from unit.
See Figure 5 for location of sensor strain relief. The sensor connection
is made at the P1 Connector on the Display Upper Circuit Board.
See figure 9 for connection information

SPECIFICATIONS

The sensor is a negative temperature coefficient (NTC) thermistor
sensor. The sensor resistance decreases with temperature increase.
It is .25 x 1.94 long with 8 feet #22 AWG cable. The thermistor has a
reference resistance of 30,000 ohms at 77°F (25°C).

Figure 11:
Resistance vs Temperature
Sensor including 8 foot cable.

Replacement Sensor – Order
Uni-Line Number 1309007-044
(OEM Number 1309007-048)

For Technical Service
Telephone 1.800.445.8299
TechnicalService@robertshaw.com

Robertshaw®, Ranco®, Paragon® and Uni-Line® are
trademarks of Robertshaw, its subsidiaries and/or
affiliated companies. All other brands mentioned
may be the trademarks of their respective owners.

www.robertshaw.com
©2018 Robertshaw
02/18 –352-00008-00 Rev C