Faults And Protection Codes For Ptac/Pthp Control Board; Solid State Digital Controls-Lui Display Codes - McQuay PDAA Installation & Maintenance Data

Fault and Protection Codes for Applied PDAA/PDHA Control Board
Fault code Description
Communication Error
CE
Missing Shunt
Sh
Problem with IAS
E1
Problem with ICS
E2
Problem with OCS
E3
Problem with OAS
E4
Problem with HFLO Sensor
E5
Protection
Description
code
Coil Freeze Protection
CF
Room Freeze Protection
Rf
High Room Temperature
hI
Low Room Temperature
Lo
Low Ambient Lockout
LA
Solid State Digital Controls – Local User Interface Display Codes
Fault code Description
Control Lockout –
LC
Control Lockout –
nL
Normal Control
Damper Closed
CL
Auto Damper
AU
Auto HP/E
AU
HP/E Bypass
bY
Coil Freeze Protection
CF
Room Freeze Protection
rF
Coil freeze protection
Lo
Temperature Limiting
Hi
Low Ambient Lockout
LA
Indoor Air Sensor
E1
Indoor Coil Sensor
E2
Outdoor Coil Sensor
E3
Outdoor Air Sensor
E4
Cause for the fault
1. Cable not plugged in properly on either LUI or relay board.
2. Defective cable.
The user configurable shunt for System Select, Control Select Off Fan Cycle, and/or Hydronic Valve is
missing or not placed properly.
Indoor Air Sensor missing or short.
Indoor Coil Sensor missing or short.
Outdoor Coil Sensor missing or short.
Outdoor Air Sensor missing or short.
HFLO Sensor missing or short on control board or heating medium >250ºF. Check for installation /
connection of HFLO sensor. Should be on coil return line.
Cause for the fault
Indoor coil temperature has been below 32ºF for 5 minutes.
Protection feature and the displayed code are dismissed when indoor coil temperature rises above 49ºF.
Indoor air temperature has dropped below 41ºF. Protection feature and the displayed code are
dismissed when indoor room temperature rises at and above 50ºF.
Indoor air temperature is 5 degrees above maximum setpoint limit. Protection feature and the displayed
code are dismissed when indoor coil temperature rises above 50ºF.
Indoor air temperature is 5 degrees below minimum setpoint limit.
Outdoor air temperature is below 25ºF.
Cause for the fault
Displays for 5 seconds when any button is pushed when in the "lockout mode".
Displays for 5 seconds to confirm normal mode of operation when control lockout turned off.
Control setup indicator damper is in "closed" mode.
Control setup indicator damper is in "automatic" mode.
Control setup indicator heat pump electric is in automatic changeover mode (HP/E).
Control setup indicator, electric heat is bypassed when OCS > 40˚.
Indoor coil is ≤ 32˚ for at least 5 minutes. Compressor and outdoor fan stop and indoor fan continues
to run for active defrost.
Room temperature < 41˚. Damper closes (Premium board) and unit goes into heat mode.
Room temperature is 5˚ below set point.
Room temperature is 5˚ above set point.
Unit is in cooling mode and outdoor air < 25˚. Compressor will cut out.
Indoor Air Thermister Failure.
Indoor Coil Thermister Failure.
Outdoor Coil Thermister Failure.
Outdoor Air Thermister Failure.
IM 934-2 Applied PDAA/PDHA / Page 41 of 44