BS 1363. There must be only one common method of isolation for the boiler and
its control system.
The appliance must be connected to the 3A supply via a fused double-pole switch
having at least 3 mm (1/8 inch) contact separation in both poles, serving only the
boiler and the system controls.
The connection point to the mains supply should be readily accessible and
adjacent to the boiler, except for rooms containing a bath or a shower. Refer to
section 2.3 Position.
2.4.2
External Wiring & Controls
1.
The boiler is designed so that all control wiring is external to the boiler.
2.
A programmer may be used with zone valves to give independent control
of central heating and hot water.
3.
A Keston Chronotherm controller may be used to provide room
compensation and optimum stop/start control on heating only systems
4.
Control signal inputs must the 230VAC "switched live" type.
5.
A Keston outside temperature sensor may be connected as an option.
The boiler will automatically detect this connection and will operate on a
"weather compensation" basis when receiving a signal on switched live 1.
Screened cable (80% density) must be used to connect the outside
temperature sensor.
2.5
BOILER SIZE SELECTION
The C45, C40P and C55(P) will automatically adjust heat output and pump speed to
match the system requirements at any given time. Efficiency and combustion levels are
maintained at optimum levels throughout the possible output range. The C45, C40P and
C55(P) are therefore suitable for all systems with a total heat load within the maximum
range of the boiler.
2.6
GAS SUPPLY
A gas meter should be connected to the service pipe by the local gas region or their
contractor. An existing meter should be checked preferably by the gas region to ensure
that the meter is adequate to deal with the rate of gas supply required. Installation pipes
should be fitted in accordance with BS 6891.
Minimum/Maximum Gas Pressure:
Natural gas pressure before the gas valve must be maintained at between 18 mbar (7.2 in
WG) and 22 mbar (8.8 in) while the boiler is running.
LPG pressure must be maintained between 31.5 mbar (12.4 in w.g) and 37.6 mbar (14.8
in w.g) while the boiler is running.
WD536
Chapter 2 - Boiler Location
The Keston C45, C40P, C55 & C55P
Installation & Servicing Instructions
Page : 9
5
2
1
9
3
N/U
Brown
Blue
Grey
Orange
Green/Yellow
White
V4043H1106
Zone Valve
Heating
2
1
3
Brown
Blue
Grey
Orange
Green/Yellow
V4043H1056
Zone Valve
DHW
10
8
Live
Neutral
Earth
Mains Supply
230V
Fused @ 3A
1
2
3
Programmer
ST6300A
L
N
1
3
4
1
2
6
4
Room Thermostat
T6360B1028
1
3
2
4
5
2
KESTON
C55 / C45
L
N
E
SL1
SL2
1
2
3
9
10
Cyl. Thermostat
6
8
L641A1039
C
1
2
2.4.4 Wiring Expample - Honeywell S-Plan for DHW and (Optional) Weather Compensated Heating Control
EX1
EX2
To Keston
Ext. Sensor
[Optional]
OR
Keston Spa
Cylinder Stat
C
1
2
C
1
2
6
8
Keston Spa
Overheat Stat