© Baxi Heating UK Ltd 2008
28
4.3
Electrical Connections
For the boiler to operate correctly it
requires a four wire connection. There
must be mains Permanent Live,
Neutral, Earth and a Switched Live
from the system.
For the pump to operate correctly it
must be wired back to the ‘Pump’
section of the boiler terminal block.
Ensure that the length of the earth
wires are such, that if the supply
cables are pulled out of the cable
clamps the live and neutral wires
become taut before the earth wire.
1. Remove the securing screw and pull the
wiring centre (See Fig. 1) fully forward.
The wiring must be routed through the
cable clamp.
Connect the power supplies as follows;
Permanent Live to 'Mains L'.
Neutral to 'Mains N'.
Earth to 'Mains E'.
Switched Live (from system) to ‘SwL’
Pump Live to ‘Pump L’
Pump Neutral to ‘Pump N’
Pump Earth to ‘Pump E’
2. If fitting a frost thermostat do so as
described in the kit.
3. If fitting the optional integral programmer
(Part No. 5111963) do so as described in
the kit.
4. Carry out preliminary electrical system
checks i.e. Earth Continuity, Short
Circuit, Polarity and Resistance to Earth.
For safety, leave the electrical supply
switched off and isolated until boiler
installation is complete.
See Page 31 for typical system wiring.
Optional
Integral
Programmer
Schematic wirin
g
with boiler interlock
There
must
be both mains Permanent Live and Switched Live from the
system to the boiler terminal block for the boiler protection devices to
operate correctly.
The pump
must
be wired to the boiler terminal block for the pump overrun
to operate correctly.
br - brown
b - blue
g/y - green yellow
N
N
L
E
E
SwL
L
Fused 3A
Mains Supply
Pump
supplied
from
boiler
br
b
b
g/y
g/y
Boiler PCB
Typical Frost Stat
br
From System Wiring
CH
out
DHW
on
DHW
off
out
To System Wiring
br - brown
b - blue
g/y - green yellow
N
N
L
E
E
SwL
L
Fused 3A
Mains Supply
Pump
supplied
from
boiler
br
br
b
b
g/y
g/y
Boiler PCB
Typical
Potterton
External
Programmer
Typical Frost Stat
To System Wiring
Mains
Pump
Mains
Pump
Fig. 35