System Alarms

A09: DC Failover
A09 is only available when DC Failover Box (ASPCB.24/48) is installed. The controller will not operate compressor or heater when the DC Failover Box is acti...
Wed, 28 Feb, 2018 at 5:20 PM
A10/A11: Evaporator Fan Overload/AC Loss
The normally closed evaporator overload feedback relay opens between terminals 5 & 9 when either the supply fan has been physically blocked or when it d...
Wed, 28 Feb, 2018 at 5:20 PM
A15/A16: Dirty Air Filter
If the air filter is dirty, excess pressure will build up across the filter, triggering the normally closed air pressure switch (PF) to open.  Troublesh...
Wed, 28 Feb, 2018 at 5:21 PM
A17: pLAN alarm
pLAN is the communication wire between unit 1 and unit 2 controller board. The units will act independently when the communication is lost. Troubleshoot...
Wed, 28 Feb, 2018 at 5:21 PM
A18: Clock Card Alarm
Clock Card Alarm occurs when the clock card is loose or its battery has drained. Clock card is able to track system time even when the system is not powered...
Wed, 28 Feb, 2018 at 5:21 PM
A19: Humidity Sensor Alarm
In software versions 13B40 and below, the Humidity Sensor Alarm occurs when the humidity exceeds 90% or when the sensor is disconnected. Humidity alarm only...
Wed, 28 Feb, 2018 at 5:21 PM
A20/A21/A22/A26/A27: Temp Sensor Alarm
Temperature sensor alarms occur when the sensor is defective or disconnected. Temperature sensors are not polarized and therefore can be connected in either...
Wed, 28 Feb, 2018 at 5:21 PM
A23: Two Compressor Run
The Two Compressor Run alarm occurs whenever the two units are required to use mechanical cooling at the same time. This alarm is an early warning that one ...
Wed, 28 Feb, 2018 at 5:22 PM
A24/A25: Damper Alarm
The controller verifies proper damper positioning by comparing the supply air temperature with the outdoor and indoor temperature. If the damper is complete...
Wed, 28 Feb, 2018 at 5:22 PM
A28: Generator Run
The controller receives a normally open signal (can be changed to normally closed at DGt under the D Menu) from the generator or ATS between terminals 42 an...
Wed, 28 Feb, 2018 at 5:22 PM