Carrier 25HPA6 instruction manual Check Charge

25HPA6

output is provided at the Y1 connection. Connect the solenoid as shown in the wiring label diagram. This is a 24vac output that is energized whenever the compressor is energized. It closes, in the compressor off mode, to prevent refrigerant migration into the unit through the liquid-line.

On Systems with Accessory Liquid Solenoid Using a Non-Communicating Thermostat: The liquid solenoid is connect to the Y1 and C terminal connections. The liquid solenoid closes, in the compressor off mode, to prevent refrigerant migration into the unit through the liquid-line.

Check Charge

Charged in high or low stage

Factory charge amount and desired subcooling are shown on unit rating plate for high stage. Charging method is shown on information plate inside unit. To properly check or adjust charge, conditions must be favorable for subcooling charging. Favorable conditions exist when the outdoor temperature is between 70_F and 100_F (21.11_C and 37.78_C), and the indoor temperature is between 70_F and 80_F (21.11_C and 26.67_C). Follow the procedure below:

Unit is factory charged for 15ft (4.57 m) of lineset. Adjust charge by adding or removing 0.6 oz/ft (17.74 g/m) of 3/8 liquid line above or below 15ft (4.57 m) respectively.

For standard refrigerant line lengths (80 ft/24.38 m or less), allow system to operate in cooling mode at least 15 minutes. If conditions are favorable, check system charge by subcooling method. If any adjustment is necessary, adjust charge slowly and allow system to operate for 15 minutes to stabilize before declaring a properly charged system.

If the indoor temperature is above 80_F (26.67_C), and the outdoor temperature is in the favorable range, adjust system charge by weight based on line length and allow the indoor temperature to drop to 80_F (26.67_C) before attempting to check system charge by subcooling method as described above.

If the indoor temperature is below 70_F (21.11_C), or the outdoor temperature is not in the favorable range, adjust charge for line set length above or below 15ft (4.57 m) only. Charge level should then be appropriate for the system to achieve rated capacity. The charge level could then be checked at another time when the both indoor and outdoor temperatures are in a more favorable range.

NOTE: If line length is beyond 80 ft (24.38 m) or greater than 20 ft (6.10 m) vertical separation, See Long Line Guideline for special charging requirements.

Heating Check Chart Procedure

To check system operation during heating cycle, refer to the Heat Pump Charging Instructions label on outdoor unit. This chart indicates whether a correct relationship exists between system operating pressure and air temperature entering indoor and outdoor units. If pressure and temperature do not match on chart, system refrigerant charge may not be correct. Do not use chart to adjust refrigerant charge.

NOTE: In heating mode, check refrigerant charge only when pressures are stable. If in doubt, remove charge and weigh in correct refrigerant charge.

NOTE: When charging is necessary during heating season, charge must be weighed in accordance with unit rating plate, ±0.6 oz./ft (±17.74 g/m). of 3/8-in. liquid-line above or below 15 ft (4.57 m)., respectively.

EXAMPLE:

To calculate additional charge required for a 25-ft. line set:

25 ft. - 15 ft. = 10 ft. X 0.6 oz./ft. = 6 oz. of additional charge.

MAJOR COMPONENTS

2-Stage Control Board

The HP control board controls the following functions:

SHigh and low stage compressor contactor operation S Outdoor fan motor operation

S Reversing valve operation S Defrost operation

S Low ambient cooling

S Crankcase heater operation

S Compressor external protection S Pressure switch monitoring

S Time Delays

Field Connections

On non-communicating (non-Infinity) system, the two-stage control receives 24vac low-voltage control system inputs through the R, C, Y1, Y2 and O connections located at the bottom of the control board (see Fig. 6.) On a non-communicating system, output W1 is connected at the bottom of the control board for auxiliary heat.

For a communicating system, use the ABCD Infinity connections.

Two Stage Compressor

The two stage compressor contains motor windings that provide 2-pole (3500 RPM) operation.

Compressor Internal Relief

The compressor is protected by an internal pressure relief (IPR) which relieves discharge gas into the compressor shell when differential between suction and discharge pressure exceeds 550-625 psi. The compressor is also protected by an internal overload attached to motor windings.

Compressor Control Contactor

The contactor has a 24volt coil. The electronic control board controls the operation of the contactor.

TROUBLESHOOTING

Systems Communication Failure

If communication with the Infinity control is lost with the User Interface, the control will flash the appropriate fault code. (See Table 4.) Check the wiring to the User Interface and the indoor and outdoor units.

Model Plug

Each control board contains a model plug. The correct model plug must be installed for or the system to operate properly. (See Table 3.)

Table 3 – Model Plug Information

MODEL	MODEL PLUG	PIN RESISTANCE
		(K--- ohms)
NUMBER	NUMBER
		Pins 1--- 4	Pins 2---3
25HPA624	HK70EZ041	18	91
25HPA636	HK70EZ043	18	150
25HPA648	HK70EZ045	18	220
25HPA660	HK70EZ047	18	360

The model plug is used to identify the type and size of unit to the control.

On new units, the model and serial numbers are input into the board’s memory at the factory. If a model plug is lost or missing at initial installation, the unit will operate according to the information input at the factory and the appropriate error code will flash temporarily. An RCD replacement board contains no model and serial information. If the factory control board fails, the model plug must be transferred from the original board to the replacement board for the unit to operate.

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