Bryant R-22 service manual 2230V Brown-Out Protection Defeated, Stage Control Board

MODEL

PLUG

UTILITY RELAY *

UTILITY SIGNAL

OPEN RELAY

MODEL

PLUG

LLS

* SUPPLIED BY UTILITY PROVIDER	Liquid Line Solenoid
A06525	A06526

Fig. 54 – 2-Stage Control Board

TROUBLESHOOTING

Systems Communication Failure

If communication with the Evolution control is lost with the User Interface, the control will flash the appropriate fault code. (See Table 23.) Check the wiring to the User Interface and the indoor and outdoor units.

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.

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 compressor contactor.

2.Keep the outdoor fan operating for 15 minutes.

3.Display the appropriate fault code (see Table 23).

4.After a 15 minute delay, if there is a call for cooling or heat- ing and LPS or HPS is reset, the compressor contactor 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 or heating.

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 (in cooling) for airflow restrictions, or in- door airflow in heating.

8.In the event of a low-pressure switch trip or low-pressure lockout, check the refrigerant charge and indoor airflow (cooling) and outdoor fan operation and outdoor coil in heating.

Control Fault

If the outdoor unit control board has failed, the control will flash the appropriate fault code (see Table 23). 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 23).

2230V 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 SYSTXBBUID01-B), or can be initiated through the forced defrost pins for non-communicating systems as follows:

The brownout toggle is accomplished by sorting 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.

Status code 6 shows the brownout is disabled. 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

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