nvent RAYCHEM T2000 - Page 35

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Procedure: Adjust the HIGH CURRENT ALARM level to the desired value. Note that the
HIGHCURRENTALARMmustbeenabledinordertoadjusttheHIGHCURRENTALARM
level. Also note that the HIGH CURRENT ALARM level is affected by the CURRENT TURNS
RATIO setting. The absolute maximum adjusted HIGH CURRENT ALARM level is 300.0 A.
TheabsoluteminimumadjustedHIGHCURRENTALARMlevelis0.1A.SeeSection3.4.14for
more information regarding the CURRENT TURNS RATIO function.
IMPORTANT:
• The HIGH CURRENT ALARM does not necessarily have to be enabled for control modules
using PROPORTIONAL or PROPORTIONAL AMBIENT SSR control modes, since they will
attempt to automatically protect themselves from overload.
• The HIGH CURRENT ALARM can be used effectively to guard against accidental paralleling
of heating circuits. In-rush, or cold start currents typically associated with self-regulating
cables may cause nuisance HIGH CURRENT ALARMS. If this is undesirable this alarm should
be disabled.
3.5.10 LOW LOAD CURRENT ALARM
Purpose: Alarms current levels, which are lower than a preset limit for the application.
Monitoring for lower than expected current levels may be an effective means of continuity
monitoring.
Alarm Mask: ENABLE or DISABLE
Range: 0.3 to 60.0 A for CM 2000+
0.3 to 120% of SWITCH CURRENT RATING for CM 2000
(CURRENT TURNS RATIO = 1.00)
Procedure: Adjust the LOW CURRENT ALARM level to the desired value. Note that the
LOWCURRENTALARMmustbeenabledinordertoadjusttheLOWCURRENTALARMlevel.
Also note that the LOW CURRENT ALARM level is affected by the CURRENT TURNS RATIO
setting.TheabsolutemaximumadjustedLOWCURRENTALARMlevelis300.0A.Theabsolute
minimum adjusted LOW CURRENT ALARM level is 0.1 A. See Section 3.4.14 for more
information regarding the CURRENT TURNS RATIO function.
IMPORTANT:
• (for CM 2000 only) To minimize nuisance LOW CURRENT ALARMS, the CM 2000 control
module must detect a current level less than the LOW CURRENT ALARM setpoint for a
period longer than approximately 20 consecutive seconds.
• For series type heating cables, adjusting the LOW CURRENT ALARM to 50% of full load
current will properly alarm a problem and reduce nuisance alarms due to voltage dips.
Parallel heaters should be adjusted to a level as close as possible to full load current but
lower than the current at worst case voltage. The low current setting as a percentage of
fullloadcurrentwillvarydependingonthefacilityanditspowersystem.
• A LOW CURRENT ALARM may also result from a switch failed open. The control module
cannot detect a switch failure due to no current. A no current condition would be identified
by a LOW CURRENT ALARM (if enabled) and the analog value reported with the alarm
will be 0.0 A.
3.5.11 HIGH GROUND FAULT CURRENT ALARM
Purpose: Alarms ground fault current levels, which are higher than a preset limit for the
application.
Alarm Mask: ENABLE or DISABLE
Range: 20 to 100 mA
Procedure: Adjust the HIGH GFI ALARM level to the desired value. Note that the HIGH GFI
ALARM must be enabled in order to adjust the HIGH GFI ALARM level.