Eaton Digitrip 520MCV, Instructions Manual

Page: 30 / 34

Effective 8/2006
Page 30
I.L. 66A7534H04
Symptom Probable Cause Possible Solution(s) References
Current through breaker is
<25% of sensor rating No problem. Status LED will
not operate with breaker
currents <25% of sensor
rating Unit status LED is not blinking
Trip unit is malfunctioning Replace trip unit
Light loading No problem. Unit Status LED
will not flash until 25% of
sensor rating See Note in Section 3.2 Unit Status LED is steady on
Trip unit is malfunctioning. Replace trip unit
Rating plug is not installed or
is loose Install rating plug and/or
check for loose connections
Rating plug is open internally Replace rating plug
As soon as current starts to
flow through the breaker, it
trips and the Instantaneous
trip LED comes on
Trip unit is malfunctioning Replace trip unit.
Battery installed backwards Install correctly
Dead battery Replace battery
LED does not come on when
battery check button is
pressed
Trip unit is malfunctioning Replace trip unit
There actually is a ground
fault Find location of the fault
CH Type-V current sensors in
one or more phases have
incorrect polarity Verify circuit breaker wiring Refer to Appendix C
Trip unit is malfunctioning Replace trip unit
Breaker trips on ground fault
High inrush phase currents
may cause fictitious ground
pickup momentarily Connect Zout to Zin jumper to
provide some time delay See Caution in Section 3.3
Connection from Zout to Zin is
missing Make connections B8 to B9 Refer to Appendix A
Trip unit settings are not
correct Change settings
Breaker trips too rapidly on
ground fault or short delay
(Zone Selective Interlocking
not used)
Trip unit is malfunctioning Replace trip unit.
Long Time Memory selected Turn off Long Time Memory Refer to Section 4.3 Breaker trips too rapidly on
long delay
Trip unit settings are not
correct Change settings. Long Time
Delay setting is based on 6
×
Ir
Appendix B Troubleshooting Guide