Troubleshooting
105
TemBreak
PRO
P_SE-UM-001-EN
– V1.2.0
Problem description
Possible cause
Remedial advice
4
OCR over temperature alarm
(Internal OCR temperature > 105°C)
Excessive ambient temperature.
Verify ambient temperature surrounding the MCCB do not exceed the maximum rated
ambient temperature range (-25°C...+70°C)
Loose terminal screw or conductor
connecting screw.
Verify and correct any loose connections to load and line terminals.
Refer to torque and connection requirements in TemBreak
PRO
P_SE Installation
Instructions supplied with MCCB
Increased contact resistance,
loose internal connection or
contact failure.
Replace MCCB
High proportion of high frequency
distortion in load current.
Decrease distortion content of load circuit
5
Abnormal voltage on load side
Excessive wear of contacts
Replace MCCB.
Foreign matter interfering with
contacts or contact surfaces
6
Failure in ON position
Reset operation not conducted
after tripping operation.
Perform reset operation.
7
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
8
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
9
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
10
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)
Summary of Contents for Terasaki TemBreak PRO P SE Series
Page 106: ...106 TemBreak PRO P_SE UM 001 EN V1 2 0 Annex A Dimensions P160 Dimensions...
Page 107: ...Annex A Dimensions 107 TemBreak PRO P_SE UM 001 EN V1 2 0 P250 Dimensions...
Page 108: ...Annex A Dimensions 108 TemBreak PRO P_SE UM 001 EN V1 2 0 P400 Dimensions...
Page 109: ...Annex A Dimensions 109 TemBreak PRO P_SE UM 001 EN V1 2 0 P630 Dimensions...
Page 111: ...111 TemBreak PRO P_SE UM 001 EN V1 2 0 Annex C I2t Let Through Curves P160_SE...
Page 112: ...Annex C I2t Let Through Curves 112 TemBreak PRO P_SE UM 001 EN V1 2 0 P250_SE...
Page 113: ...Annex C I2t Let Through Curves 113 TemBreak PRO P_SE UM 001 EN V1 2 0 P400_SE...
Page 114: ...Annex C I2t Let Through Curves 114 TemBreak PRO P_SE UM 001 EN V1 2 0 P630_SE...
Page 115: ...115 TemBreak PRO P_SE UM 001 EN V1 2 0 Annex D Peak Let Through Curves P160_SE...
Page 116: ...116 TemBreak PRO P_SE UM 001 EN V1 2 0 P250_SE...
Page 117: ...117 TemBreak PRO P_SE UM 001 EN V1 2 0 P400_SE...
Page 118: ...118 TemBreak PRO P_SE UM 001 EN V1 2 0 P630_SE...
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