29
R e s i d e n t i a l H & V - 6 0 H z H F C - 4 1 0 A
R e v : O c t o b e r 5 , 2 0 2 1
c l i m a t e m a s t e r.c o m
Electrical - Thermostat Wiring
⚠
CAUTION!
⚠
CAUTION!
Many units are installed with a factory or field
supplied manual or electric shut-off valve.
DAMAGE
WILL OCCUR
if shut-off valve is
closed
during unit
operation. A high pressure switch must be installed on
the heat pump side of any field provided shut-off valves
and connected to the heat pump controls in series with
the built-in refrigerant circuit high pressure switch to
disable compressor operation if water pressure exceeds
pressure switch setting. The field installed high pressure
switch shall have a cut-out pressure of 300 psig and a
cut-in pressure of 250 psig. This pressure switch can
be ordered from ClimateMaster with a 1/4” internal flare
connection as part number 39B0005N02.
⚠
CAUTION!
⚠
CAUTION!
Refrigerant pressure activated water regulating
valves should never be used with ClimateMaster equipment.
Thermostat Installation
The thermostat should be located on an interior wall in a
larger room, away from supply duct drafts. DO NOT locate
the thermostat in areas subject to sunlight, drafts or on
external walls. The wire access hole behind the thermostat
may in certain cases need to be sealed to prevent erroneous
temperature measurement. Position the thermostat back
plate against the wall so that it appears level and so the
thermostat wires protrude through the middle of the back
plate. Mark the position of the back plate mounting holes and
drill holes with a 3/16” (5 mm) bit. Install supplied anchors
and secure plate to the wall. Thermostat wire must be 18
AWG wire. Wire the appropriate thermostat as shown in
Figures 24 and 25 to the low voltage terminal strip on the
CXM (units with PSC motor) or ECM control board (units
with ECM motor). Practically any heat pump thermostat will
work with these units, provided it has the correct number of
heating and cooling stages.
Figure 24: Units With Optional ECM Fan
ATP32U04 Thermostat
Connection to ECM Control
Compressor
Compressor Stage 2
Reversing Valve
Fan
24Vac Hot
24Vac Common
Fault LED
ECM
Board
Y1
Y2
W
DH
O
G
R
C
AL1
Y1
Y2
W
DH
O
G
R
C
L
Dehumidification
Units with ECM fan motor, utilizing ECM dehumidification mode
Notes:
1) ECM dehumidification mode slows down fan speed in the cooling mode when
dehumidification output from thermostat is active. Normal heating and cooling fan
speeds are not affected.
2) ECM board DIP switch SW9 must be in dehumidify mode for
ECM dehumidification mode.
Auxiliary Heat
Figure 25: Typical Thermostat 2 Heat/1 Cool (PSC Fan)
ATA21U01 Thermostat
Connection to CXM Control
Compressor
Heating Stage 2
Reversing Valve
Fan
24Vac Hot
24Vac Common
Fault LED
Y
Y2/W
O
G
R
C
L
Y
W
O
G
R
C
AL1
CXM
