Vav Damper Failure - Trane Symbio 210 Installation, Operation And Maintenance Manual

Troubleshooting

VAV Damper Failure

Hazardous Service Procedures!
The maintenance and troubleshooting procedures recommended in this section of the manual
could result in exposure to electrical, mechanical or other potential safety hazards. Always
refer to the safety warnings provided throughout this manual concerning these procedures.
When possible, disconnect all electrical power including remote disconnect and discharge all
energy storing devices such as capacitors before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvertently energized. When necessary to work
with live electrical components, have a qualified licensed electrician or other individual who
has been trained in handling live electrical components perform these tasks. Failure to follow
all of the recommended safety warnings provided, could result in death or serious injury.
In the event that the air valve does not modulate, check the following:
•
•
•
•
64
Tracer SC or Tracer TU service tool has enabled an override function in the Symbio 210. Verify
no overrides are present by clicking on the override icon of multistate value 2, Air Flow Override,
on the TU Multistate Status page.
– The overrides are Open, Closed, Min, or Max. Release all overrides.
– The Symbio 210 controller is going through a recalibrate (reset) command. This is shown
in the diagnostic list in Tracer TU service tool.
– Wait for calibration to finish.
Zone temperature is greater than the heat setpoint or less than the cool setpoint. Change the
heat and/or cool setpoint.
Actuator not driving full drive time.
– Drive time on TU Setup Parameters page, Stroke Times group, not set at 90 seconds on
current Varitrane units.
– Adjust to correct damper travel time using Tracer TU service tool.
– Damper actuator loose on shaft.
– Tighten damper actuator set screw to damper shaft by first rotating damper fully clockwise
until closed, releasing actuator clutch and rotating actuator collar fully clockwise, and then
tightening the setscrews. Incorrect adjustment can result in broken stub axle adapters.
– Measure the power input to XFMR 24 Vac input and
supply voltage should be between 20.4 to 27.6 Vac (24 Vac nominal). 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. Refer
to the section, "Appendix: Typical Trane Factory Wiring Diagrams," p.
Actuator motor has failed.
– Check the incoming power to the Symbio 210 controller on XFMR 24 Vac input and
supply. The voltage should measure 24 Vac, ± 15%. Measure for the proper voltage at XFMR
24 Vac input and . Check damper actuator motor by applying 24 Vac directly to common
(blue) and jumper open (black) wire to ground to drive damper open. Damper should drive
open. If not, replace damper actuator.
– Check damper actuator motor by applying 24 Vac directly to common (blue) and jumper
closed (red) wire to ground to drive damper closed. Damper should drive closed. If not,
replace damper actuator.
– The Symbio 210 controller outputs are switched to ground via low-side triac solid-state
switches. Because the binary outputs are triac based, the state of the output is difficult to
WARNING
on the Symbio 210 controller. The
73.
TRIAC
BAS-SVX084A-EN