VAV-SVX01C-EN
77
Troubleshooting
•
Electric heat stage should energize. If it does not; check wiring, safeties and electric heat
contactor. Replace components as necessary.
VAV Proportional Hot water failure
Check binary outputs
In the event that the heat outputs are not energizing, properly inspect the following:
1.
Zone temperature is at or above the heating set point
•
Increase the UCM heating set point.
2. Verify the output configuration in the UCM setup menu
•
Unit needs to be configured as proportional hot water
3. Tracer Summit has the heat output disabled
•
Check group, global, and/or Tracer overrides to make sure they are not inhibiting heat
operation.
4. Heat relays have failed
•
If VAV UCM is calling in the status menu for the valve to be open and it is not then check UCM
Triac output; wiring; and Relay output.
•
Check J8 to TB1-2. Should have 24 VAC; if it does not if not measure the power input to TB1-
1 (power) and TB1-2 (ground) of the UCM board. The supply voltage should be between 20
and 28 VAC (24 VAC cataloged). However, voltages at either extreme may result in system
instability.
•
Heat Triac(s) can be checked with purchasing a 24 VAC LED and see if it lights up on call for
Heat output to be open or closed by UCM. If LED does not light up replace UCM.
Notice:
UCM Outputs are switched to ground. Do not jump 24 VAC to J9, J10, or J11 because damage
will occur.
Check controller proportional hot water logic
•
Reconfigure the controller setup from a VariTrane F unit into a VariTrac unit with proportional
hot water heat.
•
Recalibrate unit.
•
Drive time configured in rover should be 120 seconds.
•
Raise the temp 4° above the space temp (4 degrees offset must be maintained during test) it
should take 3.2 min. from close to open. The temperature from space to setpoint must remain
4 degrees over the length of the test. If unit does not pass test check actuator and valve. After
valve and actuator are found to be ok, repeat test and if it is still failing replace controller.
Note:
If the controller is not reconfigured as a varitrac unit and remains configured as a varitrane
unit with proportional hot water it would take 1.1 hrs to move from completely closed to
completely open.
•
Put original configuration back in controller
Summary of Contents for VAV-UCM 4.2
Page 1: ...May 2010 VAV SVX01C EN Installation Operation Maintenance VAV UCM 4 2...
Page 81: ...VAV SVX01C EN 81 Troubleshooting Figure 46 Single duct with single phase voltage electric heat...
Page 82: ...82 VAV SVX01C EN Troubleshooting Figure 47 Single duct with three phase voltage electric heat...
