Trane VAV-UCM 4.2, Installation & Maintenance Manual

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VAV-SVX01C-EN 41
UCM Programming and Operation
Parallel Fan Control: This entry will determine if a parallel fan will be controlled based on
zone temperature or on flow conditions. If "Parallel fan control" has been edited to "DEG" the
fan control offset will be entered as a temperature offset (2° - 10°F) (1.1° - 5.5°C) which will be
added to the heating set point. If "Parallel fan control" has been edited to "FLOW" this line will
be entered as a percent (0 to 100%) if the unit is a VariTrane unit. The entry field on this line will
disappear if the unit does not have a parallel fan.
Note: See “Sequence of Operations,” p. 48 of this manual for details on parallel fan
operation.
BIP Configuration: Version 4.0 or higher UCMs are provided with a binary input that can be
used to monitor either an occupancy sensor or provide the status of a generic binary input. Valid
Selections: Occupancy, Generic.
BIP Configuration default is Generic. The BIP Configuration interface is for dry relay contacts
connected to TB4-1. In generic mode, the state of the input is only passed on from the UCM to
Summit. CPL code must be written in order for Summit to utilize any signal received from this
generic input. When configured as a generic input and communications are active, an
occupancy input state will be reflected by the UCM to the upper level system controller. The
upper level system controller shall be responsible for causing any system changes necessary
to provide occupied control. When configured for generic mode, loss of communications will
result in the UCM defaulting back into occupied mode. In occupancy detector mode, the
absence of a 24 VAC signal at TB4-1 indicates occupancy and the presence of 24 VAC indicates
non-occupancy. When configured for an occupancy sensor and communications are active, an
occupancy input state will be reflected by the UCM to an upper level system controller. The
upper level system controller shall be responsible for causing any system changes necessary
to provide occupied control. When configured for an occupancy sensor and communications
are not active and occupancy is detected, the UCM shall transition to the occupied mode of
operation. Upon loss of the occupancy indication from the occupancy detector, the VAV UCM
will revert back to unoccupied mode. However, when configured for an occupancy sensor and
communications are active, loss of communications does not result in the VAV UCM defaulting
to occupied mode.
Cooling Flow
Present Value: This present value shows the current flow being reported by the UCM.
Measured Value: If the present value of flow is incorrect the operator can enter the Measured
value and Cooling Flow Correction factor will automatically be recalculated.
Note: This can be used to have the correct present value at the UCM as compared to the
actual CFM at the inlet of the unit
Correction Factor: Value displayed to show how much the flow input needed to be corrected.
Auxiliary Input
Type: When the UCM version is 4.0 or higher the analog input labelled A/C0
2
can be used to
monitor either an auxiliary temperature sensor or a C0
2
sensor. Aux Input Select defaults to
Aux Tmp Sensor This entry determines the configuration of the A/C0
2
input on terminal TB3-
5 of the UCM. Selecting AUX TMP SENSOR configures the input to use an auxiliary temperature
sensor. Selecting C0
2
Sensor configures the input to use a C0
2
sensor. They are mutually
exclusive.
Value: When the UCM version is less than 4.0 or when the UCM version is 4.0 higher and the
Auxiliary Input Type is set to Temp Sensor, the current auxiliary temperature is displayed in this
field. The value is reported after applying the calibration offset by the UCM. If the temperature
sensor fails, dashes (---) display instead of the temperature.
Calibration: The auxiliary temperature calibration offset adds the offset to the value read by
the auxiliary temperature sensor.