Concord CX -
Installation
15
INSTALLATION
INST
ALLA
TION
The internal wiring of the boiler control box is shown in
Frame 15.
Wiring should be in four core PVC insulated cable, not
less than 0.75mm
2
(24/0.2mm). All fuses must be ASTA
approved to BS. 1362.
The length of the conductors between the cord anchorage
and the terminals must be such that the current carrying
conductors become taut before the earthing conductor, if
the cable or cord slips out of the cord anchorage.
System controls must be wired externally into the live
mains lead to the boiler terminal L1. If a frost thermostat
is fitted it should be wired across the time switch contacts
and if frost is likely then the system should be turned off
using the time switch settings - all other controls must be
left in the normal running position
.
The earth connection MUST NEVER be omitted.
Wire the earths as shown in Frame 13.
All wiring between entry at the rear of the boiler and the
connection box must be secured neatly under the cable
clips provided.
Wiring must never be allowed to come into contact with
the hot
boiler body.
REMOTE LIGHTS (optional)
Remote indication of ‘Boiler on’, 'Lockout’ and ‘Overheat’
are provided on printed circuit board ‘No 6A’. The load
should not exceed 1A resistive.
Do not wire these connections in conduit up to the control
box as this will make it impossible to remove the control
box for servicing and maintenance.
Connection must be made in a way that allows
complete isolation of the electrical supply - such as a
double pole switch, having a 3mm (1/8") contact
separation in both poles, or a plug and socket serving
only the boiler and system controls. The means of
isolation must be accessible to the user after
installation.
This should serve only the boiler, together with its
controls and pumps. The unswitched live supply,
which the boiler requires to allow the pump overrun
facility to operate should be controlled by the above
switched/fused supply, but should connect from there
directly to the boiler and not via any automatic time or
temperature controls.
The switched live supply should be subject to control
by time and temperature controls in the usual way.
The main pump MUST be wired back to the boiler
control box.
The mains supply to the boiler must be wired into the
boiler terminals L1, N on the ‘plug in’ connector
attached to the gas valve lead. The earth should be
wired to the earth post as shown in Frame 13.
The control box incorporates a pump overrun device
which is necessary to dissipate residual heat after
plant shutdown. It is essential that the main pump
(and shunt pump if used) is wired to the pump
terminals marked L2, N on the ‘plug in’ connector and
the earth to the earth post.
It is also essential that an unswitched live supply (that
is a live supply not interrupted by any automatic
temperature or time control) is connected to terminal L
on the plug-in connector so that the pump overrun
facility can operate. Failure to follow this procedure
will result in nuisance overheat thermostat action.
If the down draught flue thermostat is to be fitted then
the link (marked TTB) should be removed from the
plug in connector.
14 ELECTRICAL CONNECTIONS
Summary of Contents for Concord CX40
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