Local Setpoint Controller - Kele UCM-420A Operating And Installation Instructions

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Local Setpoint Controller

When the UCM-420A is used as a local setpoint controller, the potentiometer mounted on the unit may control the
setpoint. If this is not desired, a UCM-SPA setpoint potentiometer or PreCon "XA" Setpoint Option on a tempera-
ture sensor may be wired to the "Local Setpoint" terminals as shown in the wiring diagrams. (The local setpoint may
also be configured to accept a 4-20 mA or 1-5 VDC signal, although these signals would normally be used as a
remote setpoint). A 4-20 mA, 1-5 VDC, or thermistor input (with a range of 50 to 90°F)* from the process being con-
trolled allows the UCM-420A to monitor the system and provide a proportional/integral, direct- or reverse-acting
signal to the device being controlled. See page 16 for instructions on operating the UCM-420A in this mode.
EXAMPLE: LOCAL SETPOINT CONTROLLER - Static Pressure Control
In this example, the input to the UCM-420A is a 4-20 mA signal from a pressure transducer that monitors duct pres-
sure. The setpoint is adjusted by using the setpoint potentiometer mounted on the UCM-420A. The UCM-420A then
sends a 4-20 mA control signal to the VFD which controls the AHU fan speed, which in turn, determines duct pres-
sure.
AC POWER
IN
RETURN
AIR
4-20 MA
UCM-420A
VFD
P/I
CONTROL
SIGNAL
T30-030
STATIC
PRESSURE
TUBING
SUPPLY
AIR
Modes of Operation (Cont.)
9
*Other ranges available
VAV TERMINAL
VAV TERMINAL
VAV TERMINAL