Communications Setup - Pentair 920 Series Installation, Operating And Maintenance Instructions

3.9 CommunICatIons setup

INDUSTRIAL HEAT TRACING SOLUTIONS
procedure: Adjust the MAXIMUM POWER setting to the desired value. Enable or disable the alarm
as required. The POWER LIMITING ALARM need not be enabled to adjust the MAXIMUM POWER
setting.
Important:
• This is a non-latching alarm.
• This alarm is advisory and is normally disabled. It will be active if the MAXIMUM POWER setting
is set below the power output level required for temperature maintenance. In other words, if
the circuit demands the maximum power allowed and the alarm is enabled, then this alarm will
be indicated and the output switch will pulse ON and OFF to limit the average power output to a
value approximately equal to the MAXIMUM POWER setting
3.8.22 sWItCh LImItInG status (ssr onLy)
purpose: The switch limiting feature is always enabled when using an SSR output switch and
provides protection for the output switch. Enabling this alarm will only inform the user that switch
limiting is currently active and an excessively high current condition is present. The controller
pulses its output switch for a small number of cycles and reads the resulting current. If the
measured current exceeds the SWITCH RATING setting, the duty cycle of its output switch will be
varied so that an average current not exceeding the SWITCH RATING setting is maintained.
alarm mask: ENABLE or DISABLE
procedure: Adjust the SWITCH CURRENT RATING setting to the actual current rating of the SSR.
Enable or disable the alarm as required. The SWITCH LIMITING ALARM need not be enabled to
adjust the SWITCH CURRENT rating setting.
Important:
• This is a non-latching alarm.
• This alarm is normally enabled. Currents in this range cannot be considered normal and should
be investigated.
3.8.23 ContaCtor Count aLarm (v3.11 and up)
purpose: Generates an alarm if the number of off-to-on transitions of a contactor reaches or
exceeds the CONTACTOR COUNT ALARM setting. This serves as a method to perform preventative
maintenance on the contactor before a failure is likely to occur.
alarm mask: ENABLE or DISABLE
range: 0 to 999999 off-to-on transitions
procedure: Adjust the CONTACTOR ALARM setting to the desired value. The CONTACTOR ALARM
must be enabled to adjust the CONTACTOR ALARM setting.
Important: The CONTACTOR ALARM is only available if the SWITCH CONTROL MODE is set to
either DEADBAND or PROPORTIONAL AMBIENT CONTACTOR.
3.8.24 eerom data faILure aLarm
purpose: The EEROM DATA FAILURE ALARM indicates that the controller has detected a failure in
its nonvolatile memory.
alarm mask: ENABLE or DISABLE
procedure: Enable or disable alarming of a nonvolatile memory failure as desired.
Important: The EEROM DATA FAILURE ALARM should always be enabled. This memory
stores all of the controller's configuration and calibra-tion settings and the alarm will only be
generated if the microprocessor cannot bypass the failed area of its memory. This indicates an
internal problem, and the control module should be replaced and returned to Pentair Thermal
Managament for repair.
The following section describes the setup parameters that relate to the way the controller
communicates with another device. If the optional communications interface is not installed in
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