Bard WALL MOUNTED PACKAGE HEAT PUMPS WH602 User Manual
Page 14
Manual 2100-399
Page 12
THERMOSTAT WIRING
COMPRESSOR CUTOFF THERMOSTAT AND
OUTDOOR THERMOSTATS
Heat pump compressor operation at outdoor
temperatures below 0° F are neither desirable nor
advantageous in terms of efficiency. Since most
equipment at time of manufacture is not designated for
any specific destination of the country and most of the
equipment is installed in areas not approaching the
lower outdoor temperature range, the compressor cutoffs
are not factory installed.
HEAT ANTICIPATION
Both of the thermostats in Groups A and B below have
a fixed heat anticipator for stage 1 with no adjustment
required. Stage 2 has an adjustable anticipator for the
W2 connection and fixed for the W3 connection. Both
the W2 and W3 circuits are controlled by the stage 2
bulb. The only heat anticipator that needs to be
checked is stage 2 and it should be set to match the load
carried by the W2 circuit. The normal factory wiring
provides for only on electric heat contactor to be
controlled by W2, and the anticipator should be set at
.40A. If special field wiring is done, it is best to
actually measure the load but a good role is .40A for
each heat contactor controlled by W2.
Outdoor thermostats are available to hold off various
banks of electric heat until needed as determined by
outdoor temperature. The set point of either type of
thermostat is variable with geographic region and
sizing of the heating equipment to the structure
Utilization of the Heating Application Data and the
heat loss calculation of the building are useful in
determining the correct set points.
FIGURE 8
COMPRESSOR CUTOFF AND OUTDOOR THERMOSTAT WIRING
4 - 10KW 1PH --- 6 & 9KW 3-PH
15 - 20KW 1-PH & 3-PH
MIS-409
TABLE 3
THERMOSTAT WIRE SIZE
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