Chromalox 1020 User Manual

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Controller
An instrument that can control a process, using either
PID or On-Off control methods. Alarm outputs are also
available, as are other options and Serial Communica-
tions.
Refer to Alarm Operation, Limit Controller, On-Off Con-
trol, and Serial Communications.
Cool Proportional Band
The Cool Proportional Band is only applicable when a
Cool Output is used. It is the portion of the input span
over which the Cool Output power level is proportional
to the process variable value. Adjustable in input units’
equivalent to 0.5% to 999.9% of span (zero = On-Off
control). The Control action for the Cool outputs is di-
rect acting.
Refer to Control Type, On-Off Control, Heat Propor-
tional Band and Tuning.
Cycle Time
For time-proportioning outputs, cycle time is used to
define the time over which the average ON vs. OFF
time is equal to the required PID output level. The range
of values is 0.1 to 512 seconds in 0.1s steps. Shorter
cycle times will give better control, but at the expense
of reduce life when used with an electromechanical
control device (e.g. relays or solenoid valves).
Also refer to Time Proportioning.
Deadband
Refer to Overlap/Deadband.
Derivative
Refer to Rate.
Deviation Alarm
Refer to Alarm Operation.
Heat or Cool Output Power Limits
Used to limit the power level for heating or cooling to
protect the process or heaters. Adjustable from 0% to
100%. This parameter is not applicable if the primary
output is set for On-Off control.
Also refer to On-Off Control.
Heat Proportional Band
The Heat Proportional Band is only applicable when a
Heat output is used. It is the portion of the input span
over which the Heat Output power level is proportional
to the process variable value. Adjustable in input units’
equivalent to 0.5% to 999.9% of span (zero = On-Off
control). The Control action for the Heat outputs is re-
verse acting.
Also refer to Control Type, On-Off Control, Cool Pro-
portional Band, and Tuning.
Input Filter Time
Used to filter out extraneous impulses (“noise”) on the
process input. The filtered PV is used for all PV-depen-
dent functions (display, control, alarm etc). The time
constant is adjustable from 0.0 seconds (off) to 100.0
seconds in 0.5 second increments.
Also refer to Process Variable.
Input Range and Input Span
The Input Range is the overall non-restricted range as
determined by the Type parameter in the input menu.
The Input Span (or Scaled Range) is the limited work-
ing range set by the upper and lower limits in the input
menu. The input span is used as the basis for calcu-
lations that relate to the span of the instrument (e.g.
controller proportional bands).
Also refer to Scale Range Lower and Scale Range Up-
per.
Limit Controller
A protective device that can shut down a process at
a pre-set Exceed Condition, to prevent possible dam-
age to equipment or products. They are recommended
for any process where product or equipment damage
might occur, or if it could become hazardous under
fault conditions.

Chromalox 1020 Specifications

General

Brand	Chromalox
Model	1020
Category	Temperature Controller
Language	English