Nelson CM-2201, Инструкция по установке и эксплуатации

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Troubleshooting CM-2201/CM-2202
©2018 Nelson Heat Tracing Systems www.nelsonheaters.com GA2497 Rev.6
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9.4 Common Warnings/Alarms - What to Look for
The CM-2201/CM-2202 has a wide range of warning
and alarming features that may be selectively enabled or
disabled to allow the monitoring and indication of
trouble conditions. Described below are the different
warming and alarm conditions available on the CM-
2201/CM-2202, their meanings, and possible causes. The
warning settings must be below alarm settings. If an
alarm will be activated the two SSR low power will be
activated.
9.4.1
Continuity Failure
The “Continuity Failure” alarm indicates that the current being
drawn by the load is less than about 0.5 Amps and hence the
load is assumed to be disconnected
9.4.2
High Current Warning/Alarm
This Warning/alarms current levels that are greater than the
HIGH CURRENT WARNING/ALARM setting for the application.
Cause of Warning/Alarm:
•
Warning/Alarm setting too close to normal
operating
current
• High in-rush current from “cold start” of self regulating
cable
•
Damaged or partially shorted heating cable
•
“As built” cable length is greater than design value
9.4.3
Low Current Warning/Alarm
This alarms current levels which are less than the LOW
CURRENT WARNING/ALARM setting.
Cause of Warnings/Alarm:
• Warning/Alarm setting too close to normal
operating current
•
Low source voltage
•
Damaged or inoperative heating cable
•
Open connection—wiring problem
•
SSR or contactor failed open
9.4.4
Overcurrent Trip
If the controller is unable to start the cable due to high current or
after attempting to soft start it, the controller will trip its output
switch off.
Cause of Alarm:
•
Excessive in-rush current
•
Incorrect CM-2201/CM2202 settings
•
Incorrect wiring
•
Damaged cable
9.4.5
Power Limiting (Current Limiting)
This alarm indicates that the solid-state relay is limiting the
average amount of power that is applied to the trace circuit
as defined by the MAXIMUM POWER setting.
Cause of Alarm:
•
Power applied to trace circuit is being limited to
the MAXIMUM POWER setting
9.4.6
High GFI Warning
This warning ground fault current levels which are greater
than the HIGH GFI WARNING setting.
Cause of Warning:
•
Warning setting too close to normal leakage current
•
Damaged cable insulation and/or moisture present
•
Moisture in junction box
•
Poor splice or termination
•
Moisture provides conductive ground path which allows
ground fault current
9.4.7
GFI Alarm
This value sets the upper limit of allowable ground fault
leakage. Exceeding this limit will result in the output switch
being latched off and the alarm activated to indicate a
ground fault condition.
Cause of Alarm:
•
Trip setting too close to normal leakage current
•
Damaged cable insulation and/or moisture present
•
Moisture in junction box
•
Poor splice or termination
Moisture provides conductive ground path
which allows
ground fault current
9.4.8 Switch Failure
This alarm indicates that the controller senses current flow
when the output switch should be off.
Cause of Alarm
•
Some other device energized heat trace
•
Output switch has failed “closed”