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09. 06. 21. Document Number 671786
Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk
XBC75 & 85 (AS Control)
Installation Manual
8.0 FROST COIL (OPTIONAL ANCILLARY)
All inter-connections between circuit boards, blowers and sensors are
made at the factory. This diagram only shows the essential field wiring
points for clarity.
8.1 LPHW Frost Coils
8.1.1 Wiring
The heater requires a 230V~50Hz single phase supply connection to
power the thermostat and valve actuator. Remove the top cover from
the terminal box by rotating the four fixing screws half a turn, revealing
the terminal block marked LEN.
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Wiring - LPHW Frost Coil Ancillary
230VAC
Fused
Supply
8.1.2 Setting 'Frost Condition' Temperature
The LPHW heater frost coil is only enabled if the frost stat reads a ‘frost
condition’. A ‘frost condition’ temperature adjustment dial is provided
as part of the frost coil controls. The ‘frost condition’ temperature is
easily adjustable from -10 to +10°C by inserting a small screwdriver
into the adjuster aperture and rotating the spindle clockwise or
anticlockwise. It is recommended that the ‘frost condition’ temperature
is set at 4°C.
8.2 Electric Frost Coils
8.2.1 Wiring
The heater requires two connections; the relay link up and the
400V~50Hz three phase supply connection to power the heater
element. Remove the top cover from the terminal box by rotating the
four fixing screws half a turn, revealing the terminal block.
The relay connection between main controls and the frost coil module
can now be made.
8.2.2 Setting 'Frost Condition' Temperature
The electric heater frost coil is only enabled if the frost stat reads
a ‘frost condition’, the over-temperature cut-out is healthy AND a
24vac fan run signal is received from the main control panel. A ‘frost
condition’ temperature adjustment dial is provided as part of the frost
coil controls. The ‘frost condition’ temperature is easily adjustable from
-10 to +10°C by inserting a small screwdriver into the adjuster aperture
and rotating the spindle clockwise or anticlockwise. Once enabled
the electric heater frost coil will provide its maximum heat output
to achieve the ‘frost condition’ temperature set by the frost stat. It is
recommended that the ‘frost condition’ temperature is set at 4°C.
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Wiring - Electric Frost Coil Ancillary
