User manual
ELECTRICAL
CAUTION: ISOLATE THE MAINS
ELECTRICITY SUPPLY BEFORE STARTING
ANY WORK AND OBSERVE ALL
RELEVANT SAFETY PRECAUTIONS
ELECTRICAL
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR 12i System/24i System
8 716 107 375b (11/05)
27
INSTALLATION
Note: Mains supply to the boiler and system
wiring centre must be through a common
fused double pole isolator situated adjacent
to the appliance. The isolator must have a
contact separation of 3mm minimum in all
poles. The system is supplied from the boiler.
External fuse 3A.
When stripping wires always ensure copper
strands do not fall into the control box.
Access to electrical connections:
Remove boiler casing to access control panel.
1 Unscrew screw (A) and lower the control
box into the horizontal position.
2 Unscrew the three screws (B) in the control
panel and pull off the connections cover.
3 Unclip cable clamp (C).
4 Cut off the tapered cable entry to fit cable
diameter required.
5 Turn cable retaining screw (D) anti-clock-wise.
Run cable over the main crossbar and
through the cable clamp (C), ensuring there
is ample cable to reach the connectors.
Turn cable clamping screw (D) clockwise to
secure cable and replace clamp (C) into
control panel.
6 Mains power 230v connection (ST10):
Separate wires from cable end and strip to
6mm.
Connect LIVE wire to terminal (L)
Connect NEUTRAL wire to the terminal (N)
Connect EARTH wire to the connector
Note: Earth cable to be longer so that it pulls out
last if mains cable is snagged.
7 System wiring centre connection (ST10):
Remove link.
Connect LIVE wire to terminal (LS).
Connect NEUTRAL wire to terminal (NS).
Connect SWITCHED LIVE wire to terminal (LR).
Note: A pump is fitted in the boiler. There should
be no other pump fitted.
8 Refit panels.
NOTES:
• External diverter valve(s) and all other 230V
parts are not supplied with the boiler.
• A facia mounted programmer/timer should
not be fitted unless optional integral diverter
valve is used (see instructions at the rear of
this manual).
• Refer to manufacturers instructions when
connecting external parts to the wiring centre.
Worcester, Bosch cannot be held responsible
for wiring errors.
• There is an option to fit an internal diverter
valve. This also requires fitting an extra
harness and a code plug change. See
“Optional Diverter Valve” Section in these
instructions or the instructions supplied with
the integral diverter valve kit.
This option is also covered in the Fault
Finding Guide on page 55 of these instructions.
3
C
4
5
D
6
7
F1
F3
F2
SYSTEM
WIRING
CENTRE
230V
MAINS
SUPPLY
ST10
earth
switched live
live
neutral
blue
green/yellow
brown
TIMER
ROOMSTAT
TAN K STAT
WATER VALVE(S)
FROSTSTAT
boiler
demand
2
B
A
1