Carrier 24ANA Troubleshooting, Check Charge, Systems Communication Failure, Model Plug

Models: 24ANA

1 16
Download 16 pages 47.3 Kb
Page 9
Image 9
Check Charge

Check Charge

All 24ANA units must be charged in high stage only.

Factory charge amount and desired subcooling are shown on unit rating plate. 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 15 ft (4.57 m) of lineset. Adjust charge by adding or removing 0.6 oz/ft (.018 kg/m) of 3/8 liquid line above or below 15 ft (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.

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 6) Check the wiring to the User Interface, 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 4.)

The model plug is used to identify the type and size of unit to the control. On 24ANA7 models, the model plug is also used to determine the start sequence timing for each individual model.

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.

NOTE: The model plug takes priority over factory model information input at the factory. If the model plug is removed after initial power up, the unit will operate according to the last valid model plug installed, and flash the appropriate fault code temporarily.

Table 4 – Model Plug Information

MODEL

MODEL PLUG

PIN RESISTANCE

(K--- ohms)

NUMBER

NUMBER

 

 

Pins 1--- 4

Pins 2---3

 

 

 

 

 

 

24ANA724

HK70EZ001

5.1

11

24ANA736

HK70EZ003

5.1

24

24ANA748

HK70EZ005

5.1

39

24ANA760

HK70EZ007

5.1

62

 

 

 

 

24ANA124

HK70EZ009

5.1

91

24ANA136

HK70EZ011

5.1

150

24ANA148

HK70EZ013

5.1

220

24ANA160

HK70EZ015

5.1

360

Pressure Switch Protection

The outdoor unit is equipped with high- and low-pressure switches. If the control senses the opening of a high or low pressure switch, it will respond as follows:

1.De-energize the appropriate compressor contactor,

2.Keep the outdoor fan operating for 15 minutes,

3.Display the appropriate fault code (see Table 6).

4.After a 15 minute delay, if there is still a call for cooling and the LPS or HPS is reset, the appropriate compressor contac- tor is energized.

5.If LPS or HPS has not closed after a 15 minute delay, the outdoor fan is turned off. If the open switch closes anytime after the 15-minute delay, then resume operation with a call for cooling.

6.If LPS or HPS trips 3 consecutive cycles, the unit operation is locked out for 4 hours.

7.In the event of a high pressure switch trip or high pressure lockout, check the refrigerant charge outdoor fan operation and outdoor coil for airflow restrictions.

8.In the event of a low pressure switch trip or low pressure lockout, check the refrigerant charge and indoor airflow.

Control Fault

If the outdoor unit control board has failed, the control will flash the appropriate fault code. (See Table 6) The control board should be replaced.

Brown Out Protection

If the line voltage is less than 187v for at least 4 seconds, the appropriate compressor contactor and fan relay are de-energized. Compressor and fan operation are not allowed until voltage is a minimum of 190v. The control will flash the appropriate fault code (see Table 6).

230v Brown-Out Protection Defeated

The brownout feature can be defeated if needed for severe noisy power conditions. This defeat should always be a last resort to solving the problem. Defeat is available on the User Interface setup screen (available with SYSTXCCUID01-C UI) or can be initiated through the forced defrost pins for non-communicating systems as follows:

The brownout toggle is accomplished by shorting the defrost pins from power up with the OAT and OCT sensor connector removed. After 3 seconds, the status of the force defrost short and the OAT/OCT as open will be checked. If correct, then the brownout will be toggled.

SStatus code 6 shows the brownout is disabled. S Status code 5 shows the brownout is active.

After the brownout defeat is set, power down and reinstall the OAT/OCT sensor and remove the short from the forced defrost pins. As long as the short on the forced defrost remains, the OAT and OCT faults will not be cleared. The code will continue to be flashed.

24ANA

9

Page 9
Image 9
Carrier 24ANA Troubleshooting, Check Charge, Systems Communication Failure, Model Plug, Pressure Switch Protection