SECURE 425 Series Electro Mechanical Programmer Instruction Manual
- June 6, 2024
- SECURE
Table of Contents
425 Series Installation Instructions
The 425 range of traditional electro-mechanical programmers offers a simple
yet effective way of controlling hot water and central heating with the twin
circuit Diadem and Tiara also allowing independent control of both.
INSTALLATION AND CONNECTION SHOULD ONLY BE CARRIED OUT BY A SUITABLY
QUALIFIED PERSON AND IN ACCORDANCE WITH THE CURRENT EDITION OF THE IET WIRING
REGULATIONS.
WARNING: ISOLATE MAINS SUPPLY BEFORE COMMENCING INSTALLATION
Fitting the backplate:
Once the backplate has been removed from the packaging please ensure the
programmer is re-sealed to prevent damage from dust, debris etc.
The backplate should be fitted with the wiring terminals located at the top
and in a position that allows the relevant clearances around the programmer
(see diagram)
Direct Wall Mounting
Offer the plate to the wall in the position where the programmer is to be
mounted, remembering that the backplate fits to the right-hand end of the
programmer. Mark the fixing positions through the slots,(fixing centres
60.3mm), drill and plug the wall, then secure the plate in position. The slots
in the backplate will compensate for any misalignment of the fixings.
Wiring Box Mounting
The backplate may also be fitted directly onto a single gang steel flush
wiring box complying with BS4662, using two M3.5 screws. 425 electro-
mechanical programmers are suitable for mounting on a flat surface only, they
must not be positioned on a surface-mounted wall box or on unearthed metal
surfaces.
Electrical Connections
All necessary electrical connections should now be made. Flush wiring can
enter from the rear through the aperture in the backplate. Surface wiring can
only enter from beneath the programmer and must be securely clamped.
The main supply terminals are intended to be connected to the supply by means
of fixed wiring. The recommended cable sizes are 1.0mm2 or 1.5mm2 for a Diadem
/ Tiara and 1.5mm2 for a Coronet.
425 Electro-Mechanical Programmers are double insulated and do not require an
earth connection but an earth terminal is provided on the backplate for
terminating any cable earth conductors.
Earth continuity must be maintained and all bare earth conductors must be
sleeved. Ensure that no conductors are left protruding outside the central
space enclosed by the backplate.
Diadem / Tiara:
When used to control MAINS VOLTAGE SYSTEMS Terminals L, 2 and 5 should be
electrically linked by means of a suitable piece of the sleeved conductor.
When used to control EXTRA LOW VOLTAGE SYSTEMS these links MUST NOT be fitted.
Coronet:
When used to control MAINS VOLTAGE SYSTEMS Terminals L and 5 should be
electrically linked by means of a suitable piece of the sleeved conductor.
When used to control EXTRA LOW VOLTAGE SYSTEMS these links MUST NOT be fitted.
Interlocking – Diadem and Tiara only
If a Diadem or Tiara is used on gravity hot water/pumped central heating
systems the selector slides must be interlocked for correct programme
selection.
This is achieved by rotating the interlock located at the top of the HW
programme slide. First select ‘Twice’ on the HW selector slide, then select
the Off position on the CH selector slide; this will reveal the screwdriver
slot in the interlock.
Position the screwdriver in the slot and rotate anticlockwise until the slot
is almost horizontal (a stop will prevent the interlock from being turned too
far).
Check for the correct operation of programme slides. This should result in the
HW selector slide moving up to match any CH selection (twice, all day and 24
hours).
When the CH slide switch is returned to any of the lower positions (all day,
twice and off), the HW slide switch will stay in the uppermost position
reached and will have to be manually moved to the desired new position.
Typical wiring diagrams
Example circuit diagrams for some typical installations on pages 7 & 8. These
diagrams are schematic and should be used as a guide only.
Please ensure that all installations comply with the current lET
regulations.
For reasons of space and clarity, not every system has been included and
the diagrams have been simplified (for example some earth connections have
been omitted)
Other control components shown in the diagrams i.e. valves, room slats etc are
general representations only. However, the wiring detail can be applied to the
corresponding models of most manufacturers.
Cylinder and Room Thermostat Key: C = common CALL = call for heat or break
on rise SAT = Satisfied on rise N = Neutral
425 Coronet controlling typical combination boiler installation via room
thermostat
425 Coronet controlling gravity hot water with pumped heating via room stat
and cylinder stat
425 Coronet controlling fully pumped system via room stat, cylinder stat and
using a 2 port spring return valve with auxiliary switch on the heating
circuit
425 Diadem/ Tiara controlling gravity hot water with pumped heating via a room
stat
425 Diadem/Tiara controlling gravity hot water with pumped heating via room
stat and cylinder stat
425 Diadem/Tiara controlling gravity hot water with pumped heating using a 2
port spring return valve with changeover auxiliary switch on the hot water
circuit
425 Tiara controlling fully pumped system using room stat, cylinder stat and
two (2 port) spring return zone valves with auxiliary switches
425 Tiara controlling fully pumped system using a mid-position valve via room
stat and cylinder stat
Fitting the programmer
If surface wiring has been used, remove the knockout/insert from the bottom
of the programmer to accommodate it.
End view of 425 electromechanical programmer
Loosen the two ‘captive’ retaining screws on the top of the unit. Now fit
the programmer to the backplate and line the lugs on the programmer with the
flanges on the backplate.
Swing the top of the programmer into position ensures that the connection
blades on the back of the unit locate into the terminal slots in the
backplate.
Tighten the two ‘captive’ retaining screws to fix the unit securely, then
switch on the mains supply.
The tappets can now be set to suit the user’s requirements. Please refer to
the user’s guide provided.
GENERAL INFORMATION
Before handing over the installation to the user, always ensure that the
system responds correctly on all control programmes and that other
electrically operated equipment and controls are correctly adjusted.
EXPLAIN HOW TO OPERATE THE CONTROLS AND HAND OVER THE USERS OPERATING
INSTRUCTIONS TO THE USER.
Specification:
Coronet, Diadem and Tiara
Models:
Coronet:
Diadem:
Tiara:
Contact type:
Motor Supply:
Double Insulated:
Enclosure Protection:
Max. Operating Temperature:
Dirt protection: Mounting:
Purpose of Control:
Operating time limitation:
Type 1 Action Case material:
Dimensions:
Clock:
Programme selection:
Operating periods per day:
Override:
Backplate:
Design Standard:| Single Circuit 13(6)A 230V AC
Double Circuit 6(2.5)A 230V AC
Double Circuit 6(2.5)A 230V AC
Micro disconnection
(Voltage free, Coronet and Tiara only) 230-240V AC 50Hz
IP 20 Coronet 35°C Diadem/Tiara 55°C
Normal situations. 9 Pin
Industry
Standard
Wallplate
Electronic
Time
Switch
Continuous
Thermoplastic, flame retardant 153mmx112mm x 33mm 24 hours, On all day, Twice,
Off
Two
Instant advance 9
Pin terminal connection
BSEN60730-2-7
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Secure Meters (UK) Limited
South Bristol Business Park,
Roman Farm Road, Bristol BS4 1UP, UK
t: +44 117 978 8700
f: +44 117 978 8701
e: sales_uk@Securemeters.com
www.Securemeters.com
Part Number P27673 Issue 23