Heat valve control action on UCM IVs

Issue:

Heat valve control action on UCM IVs

Resolution:

The UCM controls 2-position heat valve using J8 and J9. The control action was setup to operate in reverse. Using Rover Comm4, he reset the heat outputs under the Setup tab from normally closed to normally open. The valves cycles properly now.

 

Other Question/Problem/Cause Statements:

• Why do heat valves on VAV boxes close on a call for heat instead of opening?
• Varitrane F boxes were configured with heat valve and no fan. They operated on a CCP III setup as a Delivered VAV system. All  boxes had 2-position hydronic heat. Whenever the zone called for heat (Setpoint above space temperature),  the voltage (J8 and J9) to the actuator went to zero volts and the valve would close instead of opening.

Facts:

• VAV UCM
• VAV nonLonTalk

Original wave: wave1046