Refrigerant Charging

To prevent personal injury, wear safety glasses and gloves when handling refrigerant. Do not overcharge system — this can cause compressor flooding.

NOTE: Do not vent or depressurize unit refrigerant to atmosphere. Remove and reclaim refrigerant following accepted practices.

Air Coil Fan Motor Removal

Before attempting to remove fan motors or motor mounts, place a piece of plywood over evaporator coils to prevent coil damage.

Disconnect motor power wires from motor terminals before motor is removed from unit.

1.Shut off unit main power supply.

2.Loosen bolts on mounting bracket so that fan belt can be removed.

3.Loosen and remove the 2 motor mounting bracket bolts on left side of bracket.

TROUBLESHOOTING

(Fig. 31 and 32, and Table 30)

When troubleshooting problems with a WSHP, consider the following.

Thermistor — A thermistor may be required for single- phase units where starting the unit is a problem due to low voltage. See Fig. 31 for thermistor nominal resistance.

 

90.0

 

80.0

 

70.0

(kOhm)

60.0

50.0

Resistance

40.0

30.0

20.0

10.0

0.0

0.020.0 40.0 60.0 80.0 100.0 120.0 140.0

Temperature (degF)

Fig. 31 — Thermistor Nominal Resistance

4.Slide motor/bracket assembly to extreme right and lift out through space between fan scroll and side frame. Rest motor on a high platform such as a step ladder. Do not allow motor to hang by its power wires.

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. 32.

 

AIR

 

 

 

 

AIRFLOW

COIL

AIRFLOW

 

 

 

 

 

(°F)

 

(°F)

 

 

 

a50-8163

 

 

 

 

 

THERMISTOR

 

 

 

 

 

 

 

 

EXPANSION

COAX

 

 

 

 

VALVE

 

 

 

 

FP2

FP1

 

 

CONDENSATE

 

 

 

 

OVERFLOW

LIQUID

 

 

 

(CO)

 

 

 

 

 

LINE

WATER IN

WATER OUT

LEGEND

 

 

 

AIR COIL

 

 

WATER

 

 

COAX — Coaxial Heat Exchanger

FREEZE

 

 

COIL

 

 

Airflow

 

PROTECTION

 

 

 

 

PROTECTION

 

Refrigerant Liquid Line Flow

SUCTION

COMPRESSOR

DISCHARGE

Fig. 32 — FP1 and FP2 Thermistor Location

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Carrier RHS, RVS, RDS006-060, RVR, RHR, RVC, 50RHC Refrigerant Charging, Air Coil Fan Motor Removal, Troubleshooting