Gas Supply; Electrical - Bosch Worcester 15SBi Installation And Servicing Instructions

9. Gas Supply

The 24SBi appliance requires a maximum of 2.86m
gas (G20) or 1.1m 3 /h of propane (G31). Refer to Table 1.
The 15SBi appliance requires a maximum of 1.76m
gas (G20) or 0.68m 3 /h of propane (G31). Refer to Table 1.
A natural gas appliance must be connected to a governed meter.
The installation of the gas supply to the appliance must be in
accordance with BS6891.
The meter and the pipework to the appliance must be checked,
preferably by the gas supplier, to ensure that a dynamic pressure
of 20mbar for natural gas or 37mbar for propane is available at
the appliance [equivalent to about 18mbar or 35mbar at the gas
valve inlet pressure connection] and that the gas flow is
adequate for all the installed gas appliances.

10. Electrical

Mains supply: 230V ( 50 Hz 180watts. External fuse 5A. Internal
fuse F1-4A. Spare internal fuse is supplied with the appliance.
Fig 10 - Replacement internal fuse
5
1. Control Panel Pivot
Point
2. Fuse -F1
3. Pressure Gauge
The appliance must be earthed and it must be possible to
completely isolate the appliance.
The mains cable must be 0.75mm2 (24x0.20 mm) to BS6500 -
Table 15 or 16.
The mains cable must be connected to the terminal marked L
(red or brown lead), N (black or blue lead) and the Earth stud
(green or green/yellow lead) and secured with the cable clamp.
The connection to the mains must be either : A 3A fused three-
pin plug and unswitched socket outlet (both complying with
BS1363) or a double pole isolator with a contact separation of
3mm in all poles.
NOTE: There must be no other permanent electrical supply to
the system. This ensures the safety of a single fused supply.
3
/h of natural
3
/h of natural
1
2
3
4
4. Facia Panel
5. Control Board
Assembly
10
Fig.11 . Mains electricity connections.
Earth
230V
L N
ST12
Brown
Blue
Strain relief clamp
Fig 12 - Mains Voltage External Controls Connections
Room Thermostat - 230 Volt
Ls Lr
X2
Remove link
Ls Lr
X2
A room thermostat must be suitable for mains voltage operation.
A mechanical timer, to fit into the facia, is available.
A frost thermostat should be considered where parts of the
system are remote from the appliance. For any frost thermostat
function, the boiler temperature control knob must not be set to
the 'off' position.
NOTE: In some cases these devices should not be connected
at these points. Refer to separate system wiring guide booklet.
Safety Check: If there is an electrical fault after installation check
for fuse failure, short circuits, incorrect polarity of connections,
earth continuity or resistance to earth.
Bottom Left Hand Side - Facia
Ls Lr N
External Controls
Green/yellow
N
Live
Switched Live
Neutral
Room Thermostat
Frost Thermostat - 230 Volt
N
FROST
Frost Thermostat