72 VAV-SVX01C-EN
Troubleshooting
3. If proper voltage is measured at incoming power and you have no VDC output at J3-6 and J3-
5, replace sensor. If no voltage, check up stream of controller to see were voltage has been
interrupted. See Figure 44, p. 79 to Figure 51, p. 86 for correct unit diagrams.
VAV Damper Failure Procedures
In the event that the air valve is not modulating, properly inspect the following:
1. Tracer Summit or Rover has enabled an override function in VAV UCM
• The overrides are Open, Closed, Min, or Max. Disable all overrides.
Note: See UCM programming and operation chapter to be able to release override with Rover
• UCM is going through a recalibrate (reset) command. This is shown in the diagnostic log in
Rover
• Wait for calibration to finish.
2. Zone temperature is greater than the heat set point or less than the cool set point
• Change the heat and/or cool set points.
3. Actuator not driving full drive time
• Drive time in advanced configuration not set at 90 seconds on current VariTrane units or 60
seconds for varitrac units
• Adjust to correct damper travel time using Rover software. See Operation and Programming
chapter.
• Damper actuator loose on shaft
• Tighten damper actuator set screw to damper shaft
• 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 and cause damper to not be driven its full range.
• If no voltage, check up stream of controller to see were voltage has been interrupted. See
Figure 44, p. 79 to Figure 51, p. 86 for correct unit diagrams.
4. Actuator motor has failed
• Check voltage at J1-6 to TB1-2, should have 24 VAC. If 24 VAC is not present check incoming
power to the UCM board on TB1-1 and TB1-2. Should measure 24 VAC ± 10%. If proper
voltage is measured at TB1-1 and TB1-2 and no voltage at J1-6 and TB1-2, replace UCM.
• Check motor by applying 24 VAC directly to common (blue) and jumper open (black) wire
to a ground to drive damper open.
• Damper should drive open
• Check motor by applying 24 VAC directly to common (blue) and jumper closed (red) wire
to a ground to drive damper closed
• Damper should drive closed
• If damper actuator does not open or close replace actuator
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