VAV UCM IV tied to a CCP - Why is my present minimum flow at 0 (using hyperterminal to the CCP, UCM status display) when both my cooling and heating minimum positions are set to 10% of the unit size in the UCM setpoints menu?

Issue:

VAV UCM IV tied to a CCP - Why is my present minimum flow at 0 (using hyperterminal to the CCP, UCM status display) when both my cooling and heating minimum positions are set to 10% of the unit size in the UCM setpoints menu?

Resolution:

Problem:
VAV UCM IV tied to a CCP - Why is my present minimum flow at 0 (using hyperterminal to the CCP, UCM status display) when both my cooling and heating minimum positions are set to 10% of the unit size in the UCM setpoints menu?

Solution:
Check the Group Data in the CCP.  For Group Setup, if the "Energy Saver Mode" is set to enable (default is enable), the CCP can send a command to certain group members that allows them to close below their minimum positions.  This command is sent only to occupied members of the group that are either in the cooling mode and have a zone temperature that is less than the active heating setpoint, or are in the heating mode and have a zone temperature that is greater than the active cooling setpoint. 

Also in the same menu, check the value for "Enforce Min While Unoccupied?" - if it is No (Yes is default), the unoccupied members of the group are allowed to close below their minimum positions.



CARP3694
2/15/2002

 

Other Question/Problem/Cause Statements:

• VAV UCM IV tied to a CCP - Why is my present minimum flow at 0 (using hyperterminal to the CCP, UCM status display) when both my cooling and heating minimum positions are set to 10% of the unit size in the UCM setpoints menu?

Facts:

• VariTrac III Central Control Panel (CCP)
• VariTrac III Central Control Panel (CCP)

Original wave: case1809