Carrier AQUAZONE 50RTP03-20 - Manual (Page 47)

47
TROUBLESHOOTING
When troubleshooting problems with a WSHP, consider the
cuases and solutions in Table 21.
Thermistor — A thermistor may be required for single-
phase units where starting the unit is a problem due to low
voltage.
Control Sensors — The control system employs 2 nom-
inal 10,000 ohm thermistors (FP1 and FP2) that are used for
freeze protection. Be sure FP1 is located in the discharge fluid
and FP2 is located in the air discharge. See Fig. 25.
SUCTION
COMPRESSOR
DISCHARGE
COAX EXPANSION
VALVE
FP2 FP1
LIQUID
LINE
WATER IN WATER OUT
CONDENSATE
OVERFLOW
(CO)
AIR COIL
FREEZE
PROTECTION
WATER
COIL
PROTECTION
THERMISTOR
( °F) ( °F)
AIR
COIL
AIRFLOW AIRFLOW
LEGEND
Fig. 25 — FP1 and FP2 Thermistor Location
COAX — Coaxial Heat Exchanger
Airflow
Refrigerant Liquid Line Flow