UCM4.2 configured as Bypass Controller

Issue:

UCM4.2 configured as Bypass Controller

Resolution:

The Communicating bypass unit on a CCP III is a standard UCM 4.2 that is different from other VAV UCMs in two ways:

• The address is set at 33
• The Supply Air temperature sensor is not connected at the "Zone" temp terminals, TB3-1 and TB3-2.  The SA temp is connected at "GND" (TB3-6) and the "S" terminal TB3-7.

So any VAV UCM 4.2 could be used for a communicating bypass.  Sometimes the Auxiliary temp sensor is incorrectly connected to the "S" terminal on a normal VAV unit, this will cause the zone temp to read incorrectly.

VAV UCM IV must be used on a VariTrac III CCP for the bypass damper controller.

When connecting the pressure transducer to the port in the ductwork, only use ths high side connection. Low side is not needed.

The actuator output rating is 12VA. Since power consumption for each actuator is 4VA (VAV-SVN01B-EN, pg 32), a maximum of 3 bypass dampers can be connected to 1 VariTrac bypass controller. (To control more than 3 bypass dampers requires a relay.)

Each Bypass damper is shipped with a wire harness that has 6-pin connectors that can be piggy backed on another 6-pin connector. 3 wires are used: White - Hot (J8), Black - Closed (J9), Red - Open (J10).

It should be possible to use another vendor's damper with a Trane actuator and the communicating bypass board. Part number for the sensor assembly is is 5018-6087-01 (501860870100) or SEN01157.

The communicating bypass controller will work with a VariTrac III CCP only, and not a Tracer Summit, MP580, or CCPII System.  The UCM4.2 can not be used to control a bypass damper stand-alone.

The bypass damper must be at address 33.  When the address dip switches are set at 33 the CCP III will automatically configure that UCM as a bypass controller.  Rover is not needed to configure the communicating bypass controller.

 

Other Question/Problem/Cause Statements:

• How many bypass dampers can be controlled by one bypass VAV UCM controller?
• What UCM board do we use for a communicating bypass damper?
• What is the part number for a Communicating bypass sensor?
• Can I use a Trane communicating bypass and actuator on another vendor's damper?
• Can I use the communicating bypass controller on a Tracer Summit or MP580 system?
• Wiring for Communication bypass damper
• Can communicating bypass assembly be used with CCPII
• How is a communicating bypass UCM different from an ordinary UCM?  How does a bypass UCM controller get configured?
• What is different between a UCM4.2 VAV controller and a UCM4.2 Bypass Controller

Facts:

• Tracker BMTK
• VariTrac III Central Control Panel (CCP)
• VAV nonLonTalk
• VARITRAC III CENTRAL CONTROL PANEL (CCP)
• VAV UCM

Original wave: wave8013