Technical data

24
Electrical Connections
There is a gland plate fitted to the front of the boiler, at floor level, to accept cables for power supply and controls.
A single terminal rail is fitted inside the front cover, and all external connections are made to this terminal rail.
The plug-in terminal rail facilitates easy removal for improving access during servicing and maintenance.
Power Supply
An independent isolator and fused electrical supply is recommended for each boiler. Supply 230 volt, 50Hz, single phase.
Wiring external to the boiler must be installed in accordance with IEE Regulations and any local regulations which apply.
Wiring must be completed in heat resistant 3 core cable, (size 1.0 mm2 c.s.a.) Fascia fuse rating is 2 amp. External fuses
should be 6 amp for all single boiler sizes.
To prevent drawings excessive current (>1 amp) through the boiler control panel, it is recommended that pumps
are connected via contactors.
The following electrical connections are provided on each module:
n Supply live neutral and earth
n Supply input for boiler fault and normal run signals
n Boiler fault alarm system signal output
n Boiler normal run signal output
n 0-10v analogue control signal input
n Remote on/off control input
n Boiler shunt pump output
n Safety interlock circuit input
Wiring Diagram
Purewell VariHeat Boilers
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