TEMPERATURE CONTROLLER 5002U-P
REF NO: m55A/om/201
Issue NO: 03
Page 26 of 35
A time delay can be provided for the actual output. Effects of delay are illustrated in
the diagram below.
Relay
Contact
O/p.
Off
On
LED
Indication
Off / Open
On / Close
time
time
timer Set point
Blinking
Standby operation:
For alarm types, 15 to 20, the relay action happens only after the PV has crossed the
SP after power on.
Example:
9. CONTROL FUNCTION DETAILS
Direct/Reverse Control (Output Direction):
For Heat (Reverse Action) and Cool (Direct Action) type Proportional control logic,
user has to program the proportional band for proper control. They can be changed
manually as explained in control parameters.
Control Parameter:
Proportional Band:
Proportional action is the action which the control output varies in proportion to the
deviation between the setting value and the processing temperature. If the
proportional band is narrowed, even if the output changes by a slight variation of the
processing temperature, better control results can be obtained as the offset
decreases. However, if when the proportional band is narrowed too much, even slight
disturbances may cause variation in the processing temperature, and control action
changes to ON/OFF action and the so called hunting phenomenon occurs. Therefore,
