Grant EURFBH18MAX4, Installation, Commissioning & Maintenance Instructions

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8 ELECTRICAL CONNECTIONS
Electrical connections
8.1 GENERAL
Grant Vortex boilerhouse combi models require a ~230V 1ph 50Hz supply.
It must be protected by a 5 Amp fuse.
Refer to Figures 8-1 and 8-2 for typical control system wiring diagrams for
all models.
The supply must be fused at 5 Amp and there must only be one common
isolator for the boiler and control system, providing complete electrical
isolation.
A fused double pole switch or a fused three pin plug and shuttered outlet
socket should be used for the connection.
The power supply cable should be at least 0.75 mm
2 PVC as specifi ed in BS
6500, Table 16.
All the wiring and supplementary earth bonding external to the boiler must
be in accordance with the current IET Wiring Regulations.
Any room thermostat or frost thermostat used must be suitable for use on
mains voltage.
In the event of an electrical fault after installation of the boiler, the following
electrical system checks must be carried out:
• Short
circuit
• Polarity
• Earth
continuity
• Resistance to earth
8.2 CONNECTING THE POWER SUPPLY
It is recommended that the boiler should be connected to a switched mains
power supply from a programmer or control system.
A three core cable is required to connect the boiler terminal block to the live
supply.
Refer to Figures 8-1 for typical control system wiring diagram.
The procedure is:
1.
Lift off the boiler case top panel, if it has not already been removed.
2. Remove the top of the control panel and open the cable clamp. Route
the supply cable through the hole in the rear panel (using the grommet
supplied) up to the control panel, pass it through the cable clamp and
connect to the boiler terminal as follows:
• Brown to live (terminal 1)
• Blue to mains neutral (terminal 2)
• Green/Yellow to mains earth (terminal 3)
1. Make the remaining required connections to the control panel, as
detailed in Figures 8-1 and 8-2.
2. Secure the cable in the cable clamp.
3. Place the wiring cover in position over the terminal block, taking care
not to trap any wires and secure in position with the two M4 screws
provided.
4. Ensure that all external wiring is adequately supported.
5. Re-connect the electrical supply and check operation of heating
system controls (programmer, room thermostats, etc.).
6. Refer to Instructions provided with the programmer for operation and
setting.
7. Leave the Programmer and Thermostat Instructions with the user after
installation for their future reference.
BURNER LEAD PLUG/SOCKET CONNECTOR
On all models, the electrical cable between the boiler control panel and
burner is now fi tted with an in-line 3-way plug and socket connector. This
enables the burner to be easily disconnected from the boiler control panel
for ease of removal and servicing.
8.3 FROST PROTECTION
For additional protection of either the entire heating system, or the boiler
and localised pipework, it is recommended that a frost thermostat be
installed.
Refer to Figures 8-1 and 8-2 (as appropriate) for connection details.
To protect the heating system, the frost thermostat should be sited within the
house in such a place that it can detect any rise and fall in the ambient air
temperature, i.e. in a room with a radiator.
Where the frost thermostat is installed outside the house (to protect a
boiler installed in an external boiler room or garage) or in an attic, it is
recommended that it be used in conjunction with a pipe thermostat to avoid
unnecessary and wasteful overheating of the property.
The pipe thermostat should be located on the boiler return pipe, and set to
operate at 25°C.
Ensure that the electrical supply has been
isolated before making any connections to the
boiler.
WARNING
WARNING
The Vortex boiler contains electrical switching
equipment and must be earthed.
NOTE
If the supply cord is damaged, it must be
replaced by the manufacturer, its service
agent or similarly qualifi ed persons in order
to avoid a hazard.
NOTE
Ensure that the route and length of the supply
cable is such that the boiler front cover plate
can be easily removed without disconnecting
the supply cable from the terminal block
NOTE
Ensure that the wire link, between terminals 5
and 8 on the boiler terminal block is fi tted.
WARNING
After completing electrical connections and
before reconnecting the electrical supply to
the boiler, replace the terminal block cover
and secure it using the screws provided.
NOTE
For total system protection against freezing,
particularly during extended periods without
electrical power, Grant recommend the use
of a combined heating system antifreeze and
corrosion inhibitor, used in accordance with
the manufacturer’s instructions.
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