Manual 2100-354
Page
17
THERMOSTAT INDICATOR LAMPS
The red lamp marked “EM. HT.” comes on and stays on
whenever the system switch is placed in Em. Ht. position.
The green lamp marked “Check” will come on if there is
any problem that prevents the compressor from running
when it is supposed to be.
EMERGENCY HEAT POSITION
The operator of the equipment must manually place the
system switch in this position. This is done when there is a
known problem with the outdoor section, or when the green
“Check” lamp comes on indicating a problem.
TRANSFORMER TAPS
230/208V, 1 phase and 3 phase equipment employ dual
primary voltage transformers. All equipment leaves the
factory wired on 240V tap. For 208V operation, reconnect
from 240V to 208V tap. The acceptable operating voltage
range for the 240 and 208V taps are:
TAP
RANGE
240
253 – 216
208
220 – 187
NOTE: The voltage should be measured at the field
power connection point in the unit and while the
unit is operating at full load (maximum
amperage operating condition).
COMPRESSOR CUTOFF THERMOSTAT
and OUTDOOR THERMOSTAT WIRING
Heat pump compressor operation at outdoor temperatures
below 0° F are neither desirable not 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.
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. Refer to Installation Instructions of CMH-14
Outdoor Thermostat Kit for more information.
MIS-1188
FIGURE 10
UNIT 24V TERMINAL BOARD ( 5 THRU 10 KW)
