8
9.
Indoor Blower Motor
This item is activated by the room thermostat
by COOLING/HEATING or FAN ON position. The motor is
energized through the EBTDR for PSC motors.
5-Ton “AB” Units with X-13 Motors Only
The “AB” X-13 model indoor blower motor is activated by
the room thermostat by COOLING/HEATING or FAN ON
position. The motor is energized by a 24 volt control signal
(from thermostat Y, G or W) for X-13 motors. X-13 motors
are constant torque motors with very low power
consumption.
(See
Air Flow Measurement and Adjustment
for speed
adjustment instructions).
10. Blower Interlock Relay -
This relay is used to energize the
blower during the electric heat operation. Some room
thermostats do not energize the motor during electric heat.
This relay insures blower operation when the room
thermostat energizes heat. This relay has a 240 volt coil
and an 8 amp contact relay. This relay is energized by the
electric heat kit sequencer.
EXPLANATION AND GUIDANCE (HEAT PUMP)
The heat pump is a relatively simple device. It operates
exactly as a Summer Air Conditioner unit when it is on the
cooling cycle. Therefore, all the charts and data for service
that apply to summer air conditioning apply to the heat pump
when it is on the cooling cycle, and most apply on the
heating cycle except that “condenser” becomes “evaporator”,
“evaporator” becomes “condenser”, “cooling” becomes
“heating”.
When the heat pump is on the heating cycle, it is necessary
to redirect the refrigerant flow through the refrigerant circuit
external to the compressor. This is accomplished with a
reversing valve. Thus, the hot discharge vapor from the
compressor is directed to the indoor coil (evaporator on the
cooling cycle) where the heat is removed, and the vapor
condenses to liquid. It then goes through the expansion
device to the outdoor coil (condenser on the cooling cycle)
where the liquid is evaporated, and the vapor goes to the
compressor.
E
V
A
P
O
R
A
T
O
R
C O O LIN G
SE RV IC E V A LV E
S E RV IC E P O R T
R E V E RS ING V A L V E
C
O
N
D
E
N
S
E
R
S E RV IC E P O R T
CO M P R E SS O R
S E R V IC E PO RT
A C C U M UL A TO R
EX P A N S IO N D E V IC E
C H E C K V A L VE
O R IF ICE
S E RV IC E
V A L V E
CH EC K V A L V E
O R IF IC E
IND O O R
CO IL
DIS T R IBU TO R
O U TD O O R
CO IL
E
V
A
P
O
R
A
T
O
R
H E A TIN G
SE RV IC E V A LV E
S E RV IC E P O R T
R E V E RS ING V A L V E
C
O
N
D
E
N
S
E
R
CO M PR E SS O R
S E RV IC E P O R T
AC CU M UL A TO R
C H E CK V A L VE
O R IF ICE
S E R V IC E
V A LV E
CH E C K V A L VE
O R IF IC E
IN D O O R
CO IL
DIS T RIB U TO R
O U TDO O R
C O IL
D IST R IBU TO R
HEAT PUMP REFRIGERANT CIRCUIT
