Ptac/Pthp Control Board; Solid State Digital Controls; Lui Display Codes - McQuay PDAC Installation & Maintenance Data

Fault and Protection Codes for Applied PTAC/PTHP Control Board
Fault code Description
CE
Communication Error
Sh Missing Shunt
E1
Problem with IAS
E2 Problem with ICS
E3 Problem with OCS
E4 Problem with OAS
E5 Problem with HFLO Sensor
Protection
Description
code
CF Coil Freeze Protection
Rf
Room Freeze Protection
hI High Room Temperature
Lo Low Room Temperature
LA Low Ambient Lockout
Solid State Digital Controls – Local User Interface Display Codes
Fault code Description
LC Control Lockout –
nL Control Lockout –
Normal Control
CL Damper Closed
AU Auto Damper
AU Auto HP/E
bY
HP/E Bypass
CF Coil Freeze Protection
rF Room Freeze Protection
Lo Coil freeze protection
Hi Temperature Limiting
LA
Low Ambient Lockout
E1 Indoor Air Sensor
E2 Indoor Coil Sensor
E3
Outdoor Coil Sensor
E4 Outdoor Air Sensor
IM 882 / Page 3 of 36
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 AP7809.
Cause for the fault
Indoor coil temperature has been below 30ºF 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 35ºF.
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 ≤ 30˚ 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 < 35˚. Compressor will cut out.
Indoor Air Thermister Failure.
Indoor Coil Thermister Failure.
Outdoor Coil Thermister Failure.
Outdoor Air Thermister Failure.