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VAV-SVX01C-EN
Sequence of Operations
Control Offset
Control offset may be enabled which adjusts the edited cooling and heating set points.
Recalibrate (Reset)
The recalibrate function can be enabled.
Zone Sensor Functions
The zone sensor utilizes a thermistor element to measure zone temperature. The zone sensor has
the following options:
Zone Temperature
Each zone sensor module includes a zone temperature sensor.
Set Point
A UCM will only use the zone sensor thumbwheel set point (during occupied time) if “Zone sensor
thumbwheel functions” is edited to ENABLE on the UCM setup screen.
ON Timed Override (TOV) and CANCEL Timed Override (TOV)
The ON (TOV) and CANCEL (TOV) commands can be issued by pressing the ON or CANCEL buttons
on any of the UCM zone sensor modules.
•
When an ON button on a zone sensor is pressed (shorting the zone temperature sensor circuit),
the UCM will set a TOV signal, clear the TOV cancel signal if it is set, and start the two hour timed
override timer. The TOV signal will be maintained for two minutes.
•
When a CANCEL button on a zone sensor module is pressed for at least two seconds, the UCM
must set a TOV cancel signal, clear the TOV signal if it is set, and set the timed override timer
to zero.
•
Pressing any zone sensor module’s ON or CANCEL button will not affect the zone temperature
reported from the UCM.
Note:
TOV push buttons should be pressed for at least 2 seconds and not more than 15 seconds.
Drive to Max and Go Unoccupied
When a zone sensor thumbwheel is turned to its high-end limit, indicated by a “*” on the
thumbwheel, and the ON button is pressed, the UCM will initiate a “Drive to Max” command. When
a zone sensor thumbwheel is turned to its low limit, indicated by a “**” on the thumbwheel, and
the ON button is pressed, the UCM will initiate a “Go UNOCCUPIED” command. The UCM will
maintain the command until the zone sensor set point is adjusted to within the range of 50° to 85°.
Any zone sensor module that has a thumbwheel and ON (TOV) button can initiate these commands.
Notes:
•
The UCM will not send these commands if “Zone sensor thumbwheel functions” is edited to
DISABLE on the UCM setup screen.
•
When an ICS is connected to the UCM, the UCM will pass the commands to the ICS without
taking any control action of its own. Since this is true, it may take a minute or so after the
command is initiated before the UCM actually goes unoccupied or is driven to maximum.
•
The UCM will not generate a TOV signal when a Drive Max or Unoccupied command is initiated.
•
Pressing the ON button will not affect the zone temperature reported from the UCM.
•
The UCM will remain in the Drive Max or Unoccupied status over power failures IF “*” or “**”
(respectively) have been initiated prior to the power failure.
Note:
TOV push buttons should be pressed for at least 2 seconds and not more than 15 seconds.
Summary of Contents for VAV-UCM 4.2
Page 1: ...May 2010 VAV SVX01C EN Installation Operation Maintenance VAV UCM 4 2...
Page 81: ...VAV SVX01C EN 81 Troubleshooting Figure 46 Single duct with single phase voltage electric heat...
Page 82: ...82 VAV SVX01C EN Troubleshooting Figure 47 Single duct with three phase voltage electric heat...
