MR4PMUHV Electronic Temperature/Defrost Control with Relay Pack Product/Technical Bulletin 11
Alarm and Fault Display Codes
These alarm and fault codes flash on the LED
display when the control detects the following faults.
Table 5: Display Codes and Status
Indicates an open or shorted main temperature
sensor.
Alarm is on. Compressor runs according to the Sensor Failure
Mode selected. Correct problem with sensor and cycle power
to reset control.
Indicates an open or shorted evaporator
temperature sensor.
Alarm is on. Defrost cycle is controlled by Defrost Interval and
Defrost Duration. Correct problem with sensor to reset control.
Binary input is open for longer than the Binary
Input Time Delay and Binary Input Mode
Option 1 is selected.
Alarm is on. Compressor, Defrost, and Evaporator Fan are
off.
Binary input is open for longer than Binary Input
Time Delay and Binary Input Mode Option 2 is
selected.
Alarm, Compressor and Evaporator Fan are on. Defrost may
be on or off.
Binary input is open for longer than the Binary
Input Time Delay and Binary Input Mode
Option 3 selected.
Alarm and Compressor are on. Evaporator Fan is off. Defrost
may be on or off.
Main sensor temperature has reached or
exceeded the High Temperature Alarm value.
Alarm is on. Correct problem to reset control.
Main sensor temperature has reached or fallen
below the Low Temperature Alarm value.
Alarm is on. Correct problem to reset control.
Indicates program failure.
Alarm is on. Other outputs are off. Replace control.
Ordering Information
Table 6: Ordering Information
Relay pack temperature/defrost control with two A99B sensors
Replacement control module for use in relay pack only
Relay pack without control module
Sensor, cable length: 6-1/2 ft (2 m)
Repair and Replacement
Field repair of the control should not be made. In case
of a defective or improperly functioning control, please
contact your nearest Johnson Controls/PENN™
representative.