Johnson Controls AL6B SERIES, AC6B Fault Code Display, Sensor Or Switch Fault Codes, Hard Lockout

562156-UIM-A-0610

FAULT CODE DISPLAY

The control will display any fault code that is currently active using the LED’s. The control will display the fault code, pause two seconds, and display the fault again. The control will continue the fault code display until the condition that caused the fault code no longer exists. If multiple fault codes are present at the same time, the control will display only the most recent fault.

Table 6 describes the operational faults that the control can detect. The control displays these types of errors by flashing the LED1 (Red) and/or LED2 (Green).

TABLE 6: Operational Fault Codes

Description	LED1 Flash	LED2 Flash
	Code (Red)	Code (Green)
Control Failure	ON	OFF
Operational Faults
High-pressure switch fault (not in	1	OFF
lockout yet)
System in high-pressure switch	2	OFF
lockout
System in low-pressure switch	4	OFF
lockout
Low Voltage (<19.2VAC) preventing	5	OFF
further relay outputs
Low Voltage (<16 VAC) stopped	6	OFF
current relay outputs
High-pressure switch fault (with no
communication for compressor	9	ON
operation and where Y1 and Y2
are not energized)

SENSOR OR SWITCH FAULT CODES

Table 7 describes the faults that the control can detect when a problem is present with a sensor or switch. The control displays this type of error by energizing LED1 (Red) constantly and flashing LED2 (Green). These faults typically occur when an AC unit has been operating and a problem occurs with a sensor or its wiring. These faults could also occur during installation as the AC unit is configured.

TABLE 7: Sensor or Switch Fault Codes

Description	LED1 Flash	LED2 Flash
	Code (Red)	Code (Green)
Outdoor ambient temperature	ON	1
sensor failure (short)
Outdoor ambient temperature	ON	2
sensor failure (open)

WIRING RELATED FAULT CODES

Table 8 describes the faults that the control can detect when a problem is present with the system wiring or jumper configurations. The control displays this type of error by flashing LED1 (Red) and energizing LED2 (Green) constantly. These faults typically occur when the AC unit is first installed or when a system component such as the room thermostat or indoor unit is replaced or rewired.

TABLE 8: Wiring Related Fault Codes

Description	LED1 Flash	LED2 Flash
	Code (Red)	Code (Green)
Compressor contactor miswire	1	ON
Y2 present without Y1	2	ON

LOCKOUT MODES

Soft Lockout

The control will cause a soft lockout during the following conditions. Detailed descriptions of the conditions required for the control to enter the soft lockout mode are contained in other sections of this document.

1.High-pressure switch

a.Two openings within six hours

2.Low-pressure switch

a.One opening of the switch for more than five seconds except under certain conditions.

During the soft lockout mode, the control will do the following.

1.De-energize the compressor contactor outputs (M, M1, & M2).

2.Energize the LED’s with the appropriate flash codes as described elsewhere in this document.

3.In communication applications the fault code will be stored in the thermostat. (This feature is not available for non communicating applications).

The control will reset the soft lockout condition when any of the follow- ing occur following removal of the fault condition.

1.Power is cycled to the R or Y1 inputs of the control. This will cause the soft lockout condition to be reset when the thermostat is satisfied or when the thermostat is set to SYSTEM OFF and back to HEAT or COOL mode.

2.The TEST terminals are shorted for more than two seconds.

When the soft lockout condition is reset, the control will stop displaying the fault code and will respond to thermostat inputs normally.

Hard Lockout

If four soft lockouts occur within a twelve-hour period, the control will cause a hard lockout condition. These soft lockouts can be caused by the same or different conditions. The control will function in the same way during soft and hard lockout conditions. The difference is in the requirements for resetting the lockout condition. The control will reset the hard lockout condition when any of the following occur following removal of the fault condition.

1.Power is removed from the R input of the control.

2.The TEST terminals are shorted for more than two seconds.

A hard lockout condition will not be reset when the thermostat is satis- fied or when the thermostat is set to SYSTEM OFF and back to HEAT or COOL mode. Power (24 VAC) to the control must be removed and reapplied.

When the hard lockout condition is reset, the control will de-energize the LED’s and respond to inputs/communication normally.

Wiring or Setting Related Lockouts

The control will not operate the compressor when the following faults occur. These faults can be reset using the same methods used to reset a soft lockout. However, two occurrences of these faults will not cause a hard lockout condition.

1. Presence of Y2 thermostat signal without Y1.

If a compressor wiring error is detected, the control will not operate the compressor. Once the compressor wiring error has been detected, power (24 VAC) must be cycled to the control for the control to sense the wiring change and clear the lockout condition.

14 Johnson Controls Unitary Products