Manual
2100-489
Page
17 of 26
OPTIONAL OUTDOOR THERMOSTAT
APPLICATIONS
Since most equipment at the time of manufacture is not
designated for any specific destination of the country and
are installed in areas not approaching the lower outdoor
temperature range, outdoor thermostats are not factory
installed as standard equipment, but are offered as an
option. There are also different applications for applying
outdoor thermostats. The set point of either type of outdoor
thermostat application is variable with geographic region
and sizing of the heating equipment to the individual
structure. Utilization of the heating Application Data, and
the heat loss calculation of the building are useful in
determining the correct set points.
Temperature and Humidity Controller #8403-060, along
with the Outdoor Sensor option Part #8403-061, can be
used to:
• Limit minimum outdoor temperature for cooling option.
• Limit minimum outdoor temperature for heat pump option.
• Inhibit electric heat operation for heat pumps above
selected outdoor temperature.
FIGURE 11
COMPRESSOR CUTOFF THERMOSTAT WIRING
4 & 10KW 1 PH — 6 & 9KW 3 PH
Thus, not requiring the optional compressor cut-off
thermostat or the electric heat cut-off thermostat option.
OPTIONAL COMPRESSOR CUTOFF
THERMOSTAT (See Figures 11 and 12)
Heat pump compressor operation at outdoor temperatures
below 0°F are neither desirable nor advantageous in term
of efficiency. An outdoor thermostat can be applied to
take the mechanical heating (compressor) off line, and
send the (compressor) signal to energize electric heat in
its place (to make electric heat first stage heating). This
can also be applied to bank the quantity of available
electric heat. For example: A heat pump operates with
10KW second stage heat – once the outdoor thermostat
has switched then operates 15KW without the compressor
as first stage heat.
NOTE: The additional LAB (low ambient bypass) relay is
required to prevent heater operation during low
temperature cooling operation.
FIGURE 12
COMPRESSOR CUTOFF THERMOSTAT WIRING
15KW 1 PH & 3 PH
