Carrier 50ZHA024-060 instruction manual CoolingCharging Chart, Maintenance

Table 8—Cooling Charging Chart

SUCTION LINE TEMPERATURE (°F)

Suction Line Pressure (PSIG)

OD Temp. (°F)	52	54	56	59	61	64	67	70	73	76	79	82	85	89	92
45	51	55	60	64	69	—	—	—	—	—	—	—	—	—	—
55	—	—	53	57	62	66	70	—	—	—	—	—	—	—	—
65	—	—	—	—	53	57	62	66	71	75	—	—	—	—	—
75	—	—	—	—	—	—	—	56	61	66	71	76	—	—	—
85	—	—	—	—	—	—	—	—	53	58	63	67	72	—	—
95	—	—	—	—	—	—	—	—	—	50	54	58	62	66	—
105	—	—	—	—	—	—	—	—	—	—	50	53	57	60	64
115	—	—	—	—	—	—	—	—	—	—	49	52	55	58	61
125	—	—	—	—	—	—	—	—	—	—	—	50	53	56	59

SUCTION LINE TEMPERATURE (°C)

Suction Line Pressure (kPa)

OD Temp. (°C)	361	370	387	405	423	442	462	482	502	523	544	566	589	612	636
7	11	13	15	18	21	—	—	—	—	—	—	—	—	—	—
13	—	—	12	14	16	19	21	—	—	—	—	—	—	—	—
18	—	—	—	—	12	14	17	19	21	24	—	—	—	—	—
24	—	—	—	—	—	—	—	13	16	19	22	24	—	—	—
29	—	—	—	—	—	—	—	—	12	14	17	20	22	—	—
35	—	—	—	—	—	—	—	—	—	10	12	14	17	19	—
41	—	—	—	—	—	—	—	—	—	—	10	12	14	16	18
46	—	—	—	—	—	—	—	—	—	—	9	11	13	14	16
52	—	—	—	—	—	—	—	—	—	—	—	10	11	13	15

COOLING OPERATION (SIZES 024-042)

With a call for cooling (Y/Y2), the indoor fan energizes immedi- ately whereas the contactor energizes after a 5 minute time delay (in case of initial start-up) starting the compressor and the outdoor fan motor. When the cooling demand is met, Y/Y2 de-energizes, shutting the compressor, indoor fan and the outdoor fan.

COOLING OPERATION (SIZES 048 AND 060)

These units utilize a 2 stage indoor thermostat. With a first stage call for cooling (Y1), the indoor fan (low stage) energizes immediately whereas the contactor energizes after a 5 minute time delay (in case of an initial start-up) starting the compressor (low stage) and the outdoor fan motor. If the low stage operation cannot satisfy the cooling demand, the second stage cooling (Y2) ener- gizes switching the compressor into high stage cooling through energizing an internal solenoid valve inside the scroll compressor and switching the indoor fan into high stage. When second stage cooling is satisfied, Y2 de-energizes switching the compressor and the indoor fan into low stage cooling. When the low stage cooling demand is met, Y1 de-energizes shutting the compressor, indoor fan and the outdoor fan.

HEATING OPERATION (SIZES 024-042)

With a call for heating (Y1), the indoor fan (low stage) energizes immediately whereas the contactor energizes after a 5 minute time delay (in case of initial start-up) starting the compressor and the outdoor fan motor. If Y/Y2 cannot satisfy the heating demand, the auxiliary or backup heat (W2) energizes. In case of staged heating, W3 is energized if the demand is not met. The highest airflow selected is run while the electric heat is in operation. When heating demand is met, W3, W2 and Y/Y2 sequentially de-energize shutting the compressor, indoor fan and the outdoor fan.

HEATING OPERATION (SIZES 048 AND 060)

With a first stage call for heating (Y1), the indoor fan (low stage) energizes immediately whereas the contactor energizes after a 5 minute time delay (in case of initial start-up) starting the compres- sor (low stage) and the outdoor fan motor. If the low stage oepration cannot satisfy the heating demand, the second stage

heating (Y2) energizes switching the compressor into high stage heating through energizing an internal solenoid valve inside the scroll compressor and switching the indoor fan into high stage. The auxiliary or backup heat is controlled by a third stage (W2). If the demand is not met, W3 is energized in case of staged heating. When heating demand is satisfied, W3, W2 and Y2 sequentially de-energize switching the compressor and the indoor fan into low stage heating. When the low stage heating demand is met, Y1 de-energizes shutting the compressor, indoor fan and the outdoor fan.

CONTINUOUS FAN

With the continuous Indoor fan option selected on the thermostat, G is continuously energized. In case of 024-042 units, the selected airflow setting is provided. In case of 048 and 060 units, the system runs low stage (Y1) airflow for continuous fan operation.

DEFROST

Defrost board (DB) is a time and temperature control, which includes a field-selectable time period between checks for defrost (30, 60, 90 and 120 minutes). The time period is factory-set at 60 minutes and should only be adjusted by a trained service person. Electronic timer and defrost cycle start only when contactor is energized and defrost thermostat (DFT) is closed.

Defrost mode is identical to Cooling mode. The outdoor fan motor stops because of “OF1” and “OF2” contacts opening on the defrost board, a bank of optional electric heat turns on to warm air supplying the conditioned space.

ELECTRIC RESISTANCE HEATING

If accessory electric heaters are installed, on a call for “Emergency Heat” the thermostat energizes W which energizes the heater relay and in turn energizes the electric heaters. The IFR is energized which starts the indoor-fan motor. If the heaters are staged, W2 is energized when the second stage of heating is required. When the need for heating is satisfied, the heater and IFM are de-energized.

MAINTENANCE

To ensure continuing high performance, and to reduce the possi- bility of premature equipment failure, periodic maintenance must

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