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requirements of BS5449: Part 1. The boiler must be fitted with a
spring loaded safety valve set to operate at 3 bar (45 psi) and
the pipe connections made throughout the system must be
capable of sustaining a pressure of up to 3 bar.
Copper pipework must be used through out when installing the
appliance on a sealed system.
The following is a list of major items which must be fitted to the
system:
1. Safety valve – 3 bar
2. Pressure gauge – 0 to 4 bar.
3. Expansion vessel
4. Automatic air vent.
(See Figs. 20 to 25).
10.1
The wiring between the appliance and the electrical supply
shall comply with current IEE Wiring Regulations and any local
regulations which apply.
10.2
To gain access to the electrical terminal strip.
1. Isolate the mains electrical supply.
2. Remove the cabinet top panel by pulling squarely
upwards.
3. Release the two screws securing the terminal connector
protector plate and remove.
10.3 Mains Wiring
Mains supply – 230V AC ~ 50 Hz 5A External Fuse to BS1362.
LIVE - Brown, NEUTRAL - Blue, EARTH - Green/Yellow
Mains Cable: 0.75mm
2
(24 x 0.20 mm) to BS 6500 Table 16.
The boiler and system controls must be supplied using a single
fused supply.
The mains supply cable should be connected into the terminals
marked
L
(Live),
N
(Neutral) and
E
(Earth) on the appliance
terminal strip and securely held in the cable clamp located in
the left-hand side of the electrical tray base. Feed the cable
between the side panel and the boiler insulation jacket and
route to the connection point avoiding any hot surfaces.
The appliance must be earthed.
10.4 Programmer
(See Fig. 21).
A plug in, colour co-ordinated, 2 channel electronic programmer
is available from Worcester Heat Systems Limited. Full
instructions covering installation and operation of the
programmer are included with the kit. (See Fig. 21a)
The programmer will give fully independent central heating (CH)
and hot water (HW) programmes when the switch on the rear of
the unit is set to P.
If an external programmer is to be fitted to the boiler the link
plug should be removed from the programmer terminal strip.
(See Fig. 21b). The LIVE, NEUTRAL and EARTH wires should be
connected to the LIVE, NEUTRAL and EARTH terminals on the
main terminal strip and the switched lines connected to
terminals 1 and 2.
NOTE:
The mains supply cable should not be connected to an
external time switch when a frost thermostat is fitted to the
Greenstar HE standard wiring block.
NOTE:
Under no circumstances should the timer be connected
to a separate electrical supply. Safety is assured from a single
fused supply to the boiler.
10.5 Safety Check
In the event of an electrical fault after the installation of the
appliance, the electrical system shall be checked for short
circuits, fuse failure or incorrect polarity of connections.
10.6 Pre-wired Remote “Y” or “S” Plan systems
(See Fig. 22).
If the system is fully pre-wired at a junction box remotely from
the boiler it can be connected to the boiler. The diagram shows
connection details of two proprietary systems (Honeywell and
Invensys).
The WHS facia mounted programmer can be fitted instead of an
external timer to the remote junction box. Remove the link plug
(8 to 9) and connect the programmer plug into the time clock
connector. Connect terminal 1 from the boiler terminal block to
the 'HOT WATER ON' on the remote 10 way junction box.
Connect terminal 2 from the boiler terminal block to the
'HEATING ON' on the remote 10 way junction box..
NOTE:
A “Y” Plan requires a live feed from 'HOT WATER OFF '
switch position. In order to achieve this, using a WHS program-
mer, remove the orange wire from terminal 9 and pull back
through the tie wraps. Ensure the brown wire is firmly secured in
terminal 9. Connect the orange wire to terminal 6 and connect
terminal 6 on the boiler terminal block to the 'HOT WATER OFF'
connection at the remote 10 way junction box.
10.8 Honeywell “S” Plan
(See Fig. 23).
The “S” plan provides complete control on installations having
pumped circulation to both the domestic hot water and radiator
circuits.
The domestic hot water and radiator circuits are independently
controlled by two motorised valves via a cylinder thermostat
and a room thermostat. Both thermostats switch the water
circulator and the boiler on and off.
10.9 Honeywell “Y” Plan
(See Fig. 24).
The “Y” Plan provides complete control on installations having
pumped circulation to both the domestic hot water cylinder and
radiator circuits.
The domestic hot water and radiator circuits are controlled by a
3 port motorised valve via a cylinder thermostat and a room
thermostat. Water flow is diverted to either circuit or to both
circuits at the same time. Both thermostats switch the water
circulator and the boiler on and off.
Note:
The “Y” plan requires a live feed from the hot water “off”
switch position. In order to achieve this, using a WHS
programmer, remove the orange wire from terminal 9 and pull
back through the tie wraps. Do not attempt to cut the tie wraps.
Ensure that the brown wire is firmly secured in terminal 9.
Connect the orange wire to terminal 6.
10.10 Frost Protection
(See Fig. 25).
For full frost protection a single pole double switch thermostat
should be fitted so that both the boiler and the circulating pump
circuits are energised under frost conditions. Frost protection
will be lost if there is no power supply to the boiler.
10. Electrical