GE Industrial Solutions EntelliGuard TU Trip Units - Manual (Page 71)

DEH-4567B EntelliGuard TU Trip Units: UL/ANSI Models
Maintenance and Troubleshooting
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Other General Troubleshooting Issues
• Nuisance tripping
Review Pickup, Band and Slope settings. Coordination
Study is optimal but remember EntelliGuard has Delay
bands and slopes that can be much faster than MVT.
Settings that are lower than application can support
can create nuisance tripping. E.g. Transformer or Motor
Magnetizing inrush can be up to 10 to 15X nominal and
setpoints set to low enough pickup and delay may
nuisance trip on this if not set appropriately.
• Nuisance firing of Bell Alarm on PB2
Review settings of Bell Alarm LO (lockout) and Bell Alarm
(alarm only). Consult settings instruction. Group 3 is for
Overcurrent trip only (most used setting). Many units
have had default setting of Group 15 where any trip
condition such as shunt, UVR or Prot. Relay will fire the
bell alarm. If Bell Alarm still nuisance fire with the
correct setting, contact Post Sales Service (PSS).
• Display will not come up with battery power and or
line current
The internal battery power supply can be used at 10%
or lower current and CT’s will power up the trip unit at
15% or greater. Between 10 and 15% the CT’s or the
internal battery power supply may not power the
display. A test kit or external battery pack tvpbp and
tvpbpacc can be used as well as external 24VDC power.
The backlight requires either 24V, external battery pack,
test kit or nearly full CT power.
• Nuisance trip when pressing keypad and under
communication
Contact Post Sales Service 1-888-GE-RESOLVE, 1-800-
GE-RESOLVE
• RELT Instantaneous cannot be set
If the trip unit does not have the required 24VDC control
power, it cannot read RELT inputs and will not allow
setting to be changed. You can change settings when
powered with 24VDC, test kit or battery pack.
• Confusion about GF CT vs. GF Sum
GF CT is only for special situations where an external
zero sequence detecting CT is used around all phases
and wired to an EntelliGuard G breaker (not a neutral
CT). Most applications are GF Sum (including use of a
neutral CT and those without).
• Settings cannot be changed to desired level
Check in the SETUP Long time pickup screen that the LT
pickup multiplied by the Rating plug equals the Pickup
Amps displayed (e.g. 0.5 LTPU times a 2000A plug
equals 1000A displayed on the bottom of LTPU screen.
• GF Alarm relay is not staying on
If the output Relay is used for GF Alarm, it is momentary
duty and the contacts are closed only during the GF
Fault condition.
• Breaker contact status reads incorrectly (e.g., on a
PB2 display reads Closed when breaker is Open)
Trip unit can only read correct status when trip unit if
fully powered by either CT current of approximately.
80%, 24VDC, test kit or battery pack.
• Batteries go dead prematurely (e.g., within few
months)
Excessive use of keypad (hours) can cause this.
Otherwise if load current is constantly at 10 to 20% of
CT rating, contact PSS.
• GF nuisance tripping on EntelliGuard G breakers
Verify there is not a GF sensing application issue such
as incorrect neutral sensor polarity, incorrect bonding at
neutral CT or downstream or related issues. Check
current metering when breaker is OPEN, if currents do
not read zero trip unit will need to be replaced-contact
PSS to determine if warranty.
• BIM trip
If trip unit is installed into a breaker other than the one
this was first installed in, this will occur. NEW trip units
should not cause this when first installed into a breaker.
If this occurs with a new trip unit that was not installed
in a breaker, contact PSS as the breaker BIM module
might be corrupt.
Software Revision 8.00.23 and greater: If a BIM read
fails the trip unit will not trip the breaker, instead it will
modify its internal configuration to match the AIC rating
of the least capable breaker in the family. The trip unit
will periodically read the BIM after that, and on a
successful match the original settings will be restored.
While the BIM error persists a BIM Err message will be
displayed on the LCD.
• Nuisance trip with NO EVENT information
Verify there are no accessories and that settings are not
too low in the presence of high inrush conditions at low
CT current causing the trip and then contact PSS.