Bard WH183 User Manual
Page 13
Manual 2100-373
Page 11
COMPRESSOR CUTOFF THERMOSTAT
AND OUTDOOR THERMOSTATS
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.
See Figure 8 for compressor cutoff and outdoor
thermostat wiring.
MIS-409
FIGURE 8 – COMPRESSOR CUTOFF AND OUTDOOR THERMOSTAT WIRING
4 & 8 KW 1 Phase – 6 KW 3 Phase
TABLE 3
THERMOSTAT WIRE SIZE
r
e
m
r
o
f
s
n
a
r
T
A
V
A
L
F
e
g
u
a
G
e
r
i
W
m
u
m
i
x
a
M
e
c
n
a
t
s
i
D
t
e
e
F
n
I
5
5
3
.
2
e
g
u
a
g
0
2
e
g
u
a
g
8
1
e
g
u
a
g
6
1
e
g
u
a
g
4
1
e
g
u
a
g
2
1
5
4
0
6
0
0
1
0
6
1
0
5
2
WIRING – LOW VOLTAGE WIRING
230/208V, 1 phase and 3 phase equipment 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).
Nine (9) wires should be run from thermostat subbase
to the 24V terminal board in the unit. A nine
conductor, 18 gauge copper, color-coded thermostat
cable is recommended.. The connection points are
shown in Figure 7.