User manual

22 UR3274U - User manual
NB: digital input functions are not available with sensors
PT100, NI100, NTC, PTC, PT500, PT1000 and potentiometers.
. Dual Action Heating-Cooling
UR3274U is suitable also for systems requiring a combined
heating-cooling action.
(
act.t. = Heat and with a p. b. greater than 0), and one of the
alarms (
A L .1 or AL. 2 ) must be congured as co o L. Command
output must be connected to the actuator responsible for
heat, while the alarm will control cooling action.
Parameters to congure for the Heating PID are:
act.t. = Heat Command output type (Heating)
p. b. : Heating proportional band
t.i . : Integral time of heating and cooling
t.d. : Derivative time of heating and cooling
t. c. : Heating time cycle
The parameters to congure for the Cooling PID are the
following (example: action associated to alarm1):
AL. 1 = cooL Alarm1 selection (cooling)
p.b.m. : Proportional band multiplier
ou.d.b. : Overlapping/Dead band
co.t.c. : Cooling time cycle
Parameter
p.b.m. (that ranges from 1.00 to 5.00) determines
the proportional band of cooling basing on the formula:
Cooling proportional band =
p. b. * p.b.m.
This gives a proportional band for cooling which will be the
same as heating band if
p.b.m. = 1.00, or 5 times greater if
p.b.m. = 5.00. The integral time and derivative time are the
same for both actions.