34 Direct-Fired Indoor and Outdoor Units • MUA-SVP01A-EN
Diagnostics
– Yes. There is a short in the wiring between these terminals. Determine
cause and rectify.
– No. Replace controller.
FAULT CODE:Unit on/Fan off
PROBLEM:The controller has activated the unit enable output to start the fan, but
the fan status input, is not receiving a signal that the fan is running. This fault will
automatically clear about 60 seconds after the fault is corrected. Turning the unit
off and then on will clear this fault at any time.
SOLUTION:If fan/motor is running
1. Is the BACview remote indicating an alarm?
– Yes. Check previous alarms and continue.
– bContinue.
2. Is the motor starter's normally open auxiliary contact, closed?
– No. Replace contact.
– Yes. Continue.
3. Are the high and low velocity airflow switch contacts, closed?
– No. Are the belts on and is the fan motor.
– Yes. Contact factory. Do not adjust the switches setpoints.
– No. Determine cause and rectify.
– Yes. Continue.
4. Is the fan status relay energized?
– No. There is an open or break in the wiring. Determine cause and rectify.
– Yes. Continue.
5. Is the fan status relay's normally open auxiliary contact, closed?
– No. Replace relay.
– Yes. Continue.
6. Is there continuity at the controller between the fan status terminals?
– No. There is an open in the wiring between these terminals. Determine
cause and rectify.
– Yes. Replace controller.
SOLUTION: If fan/motor is not running
1. Is the BACview remote indicating an alarm?
– Yes. Check previous alarms and continue.
– No. Continue.
2. Is controller output LED for the unit enable output lit?
– No. There is a problem with the controller. Replace controller.