Watlow PM PLUS™ 6 • 86 • Chapter 8: Features
two million cycles at the rated full-load current.
Although a NO-ARC relay has significant life advantages, a few precautions must be followed:
Do not use:
• Hybrid relays for limit contactors. A limit or safety device must provide a positive mechanical break on all hot
legs simultaneously
• DC loads with hybrid relays. The triacs used for arc suppression will turn off only with ac line voltage
• Hybrid switches to drive any inductive loads, such as relay coils, transformers or solenoids
• Cycle times less than five seconds on hybrid switches
• On loads that exceed 264V ac through relay
• On loads that exceed 15 amperes load
• On loads less than 100mA
• NO-ARC relays in series with other NO-ARC relays
Retransmitting a Process Value or Set Point
Applicable on models with a Universal Process output 1 and 3. Check your product label to confirm the configu-
ration code shows F in the 6th or 10th digit: PM _ _ _ [F] _ - _ _ [F] _ _ _ _ .
The retransmit feature allows a process output to provide an analog signal that represents the set point or
process value. The signal may serve as a remote set point for another controller or as an input for a chart
recorder documenting system performance over time.
Outputs 1 and 3 can be ordered as process outputs. To configure these outputs, go to Operations — Setup
— Output — Output [1,3] — Function — and select Retransmit. Set the output to volts or milliamps with
Type. Select the signal to retransmit with Retransmit Source. Set the range of the process output with Scale
Low and Scale High. Scale the retransmit source to the process output with Range Low and Range High.
In choosing the type of retransmit signal, consider the input impedance of the device to be retransmitted
to and the required signal type, either voltage or milliamps. Typically applications might use the retransmit
option to record one of the variables with a chart recorder or to generate a set point for other controls in a
multi-zone application.
When the retransmit source is at the Range Low value, the retransmit output will be at its Scale Low value.
When the retransmit source is at the Range High value, the retransmit output will be at its Scale High value.
Retransmit
Retransmit Source
Output Scale
Range High
Range Low
Scale High
Scale Low
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