NHP TemBreak PRO - Troubleshooting

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TemBreak PRO B_BE-UM-001-EN  V1.1.0
Troubleshooting
In the event of a problem when using the TemBreak PRO system, this section provides advice on how to resolve issues.
Problem description
Possible cause
Remedial advice
1
Abnormal voltage on load side
Excessive wear of contacts
Replace MCCB.
Foreign matter interfering with
contacts or contact surfaces
2
Failure in ON position
Reset operation not conducted
after tripping operation.
Perform reset operation.
3
Failure in RESET position
UVT not energised
Apply voltage to UVT
Circuit breaker service life ended
due to large number of switching
cycles using SHT or UVT
Replace MCCB
Fault of tripping mechanism
4
Nuisance tripping while rated current
not reached
Vibration and/or shock
Dampen vibration of MCCB and review installation requirements
High proportion of high frequency
distortion in load current.
Decrease distortion content of load circuit
Electromagnetic induced
interference (from nearby
conductors or external radio
sources)
Review nearby sources of conducted and radiated emissions (e.g. radio sources,
high-speed switching devices including variable frequency drives)
Excessive surge
Isolate and mitigate surge source (e.g. surge protection devices)
Erroneous connection of control
circuit for SHT or UVT
Verify control wiring and supply to SHT and UVT
5
Nuisance tripping due to starting
current
Excessive inrush starting current
due to load type
Review INST and STD protection settings for load type where applicable
Switching operation of star-delta
motor starter, incorrect wiring
Verify and correct any issues with star-delta starter wiring with respect to the motor
windings and phase sequence. Refer to motor and/or starter manufacturer
Short-circuit in motor (e.g.
windings, starter circuit)
Verify and correct any issues with motor wiring. Inspect and verify motor winding
insulation. Refer to motor manufacturer
Erroneous connection of control
circuit for SHT or UVT
Verify control wiring and supply to SHT and UVT
6
No trip at pickup current
Failure in selectivity/coordination
with upstream circuit breaker or
fuse
Review selectivity/coordination study and protection parameters of each device
Incorrect protection settings
Review enabled protection settings ensuring correct pickup current and time-delay for
load type. (e.g. LTD, STD, INST pickup currents and time delays)