NorAire NC-FE series, Installation & Operating Instructions Manual

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05/16/2014 18 NI216
Variable Speed Pump
Variable pump can be used on the load side of the buffer tank, but not in the NorAire supply OUT circuits.
Low Flow, Need Larger Pump
If the IDU internal pump does not have adequate capacity or lift, add a series 2
nd
pump at the IDU “IN” pipe and
wire in parallel to the internal pump (240VAC). However, one of the OUT’s may have higher flow resistance
(head). In this case adding a small series pump in the OUT may be the best solution.
E-Tab (Compressor No Response)
If the connected ODU has an “L” or a fault wire available, extend this wire to the E tab. This must be a
continuous 24V, not pulsing or “flashes”. When this is raised to 24VAC, this controller assumes the compressor
is off and provides an alarm front panel LED plus initiates backup or emergency heat. The HP-Y will continue
until either stat W or stat Y is satisfied. Cycling of either stat W or Y will reset and the IDU controller will go
through a sequence of again evaluating the E tab input.
Pump Tab
An external contact from R to “pump” tab forces internal pump relay on. This will override any internal
software sequence.
Special Arrangement, Gas Furnace Backup with Buffer Tank Controller Option
With a field installed added wire it is possible to use the gas furnace and Buffer Tank Controller mode C as an
additional backup or standby option. See Buffer Tank Controller installation manual HI114 which will detail a
field installed wire added between this control board B/U wire or tab and the BTC board MON-A tab.
PC Remote Default or Setup Downloads
The controller left pin connector (J5) receives the Electro Industries’ special cable for PC communication to this
controller (order ET-SOFT-NA-USB). See the instruction sheet or software CD Help file accompanying this
cable.
Comment – No Factory Installed Electric Boiler
If the radiant system return (RT) is < 70° F (21° C) there may be an ODU defrost delay and problem. Adequate
refrigerant energy may not be developed from cold return water to properly defrost and permanent freeze-up of
the ODU may occur.
ODU with 2nd Stage Compressor
Where this applies, see page 15 bottom and the K6 wiring.