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to return to normal operation. For Master Slave unit, no action is needed for the Slave section.
Heating/Cooling Mode Setting
The unit heating/cooling mode can be set by the “Setting” button of the display screen. UC800 also provides
auxiliary control for a running mode. Connect a remote device contact to the J2-3 and J2-4 of module 1A19 can
realize this function. Closure of the contact activates the “Heating” mode, otherwise activates the “Cooling” mode.
Dry contact is acceptable only.
External Current Limit Setpoint - Optional
The UC800 provides inputs (J2-2 and J2-3 of module 1A22) that accept either 4-20 mA or 2-10 VDC signals to
set the
External Current Limit Setpoint. The 4-20 mA or 2-10 VDC signals are corresponding with unit 60%~120%RLA
range.
For the 2-10 VDC signal:
External current limit setpoint=7.5*Input 45.0%
For the 4-20 mA signal:
External current limit setpoint=3.75*Input 45.0%
Tracer TU Service Tool is used to set the input signal type from the factory default of 2-10 VDC to that of 4-20
mA. Tracer
TU is used to install or remove the External Current Limit Setpoint option, and adjust the maximum or minimum
value setting.
External Chilled/Hot Water Setpoint
The UC800 provides inputs (J2-5 and J2-6 of module 1A22) that accept either 4-20 mA or 2-10 VDC signals to
set the External Chilled/Hot Water Setpoint.
When unit is running under cooling mode, external water setpoint will be set as the chilled water temperature
setting. External water temperature setpoint shall have the configuration with maximum and minimum value.
When unit is running under heating mode, external water setpoint will be set as the hot water temperature setting.
External water temperature setpoint shall have the configuration with maximum and minimum value.
For the 2-10 VDC signal:
External water temperature setpoint=Minimum Value + (Maximum Value - Minimum Value)*(Input signal-2)/8
For the 4-20 mA signal:
External water temperature setpoint= Minimum Value + (Maximum Value - Minimum Value)*(Input signal-4)/16
Tracer TU Service Tool is used to set the input signal type from the factory default of 2-10 VDC to that of 4-20
mA. Tracer TU is used to install or remove the External Chilled/Hot Water Setpoint option, and adjust the
maximum or minimum value setting.
Building Automation Control System Communication Interface
LonTalk Communications Interface (LCI-C)
UC800 provides an optional LonTalk Communication Interface (LCI-C) between the unit and a Building
Automation System (BAS). An LCI-C LLID shall be used to provide "gateway" functionality between a LonTalk
compatible device and the unit.