Multilin 139 series - Problem Troubleshooting Guide

TABLE 4-2 PROBLEM TROUBLESHOOTING GUIDE
f
---SYMPTO~=~-:~- PROBABLE CAUSE_ _j_ ----AC-T-IO_N ___ _J
Relay won't reSet !.
1
-
1or.ked out alter 111µ - place short across emergency
restail terminals tor 5 seconds
then press reset
Switch 84 must be on.
. -- condition still µer:::1sts G.Q. Hot - allow motor to cool or disconnect
I RTD above trip temperature ATD input
-·--··· - -- - - - --+--- ---------- --+----~---
f:xccss1ve Unbalancf · -- unloaded new pla11t - high
'
i
Periodic Overloaa
'
'
Tripping
'
I
I
'
k--
I
I
i Start Time' IOO
short/long
!
I
I
'---
I, Start light flickers
I relay trips penodically
I
I
RTD Trip- motor not
I
running
I
I
I
I
I
I
I
I Alarm ~01 working
I
- 1mmed1ate overloads
i
-RTD
I
- ground fault
:
- undercurrent
I
Ground Fault nuisance
i
I
tripping
I
i
I
-
voltaye unbalance
-CTs incorrectly sized
d
-- per~ci 1c surges
- overload surges
- cyclic overloads (crushers etc.)
- incorrect run curve selected
-- voltage compensation switch on
- previous overload, starts shorten
time available
- lightly loaded motor causes
relay to see start cond1t1on
- hot RTD above trip temperature
- no RTD connected at motor_
- unshielded leads or nmse pickup.
- 11 using thermistor option
no thermistor connected
- not enabled inside relay
- set too sensitive
- noise
- set unt)aiance control higher
- change load distribu1mn
- check CT ral!os
- norma. w1 not cause nuisance
I
tripping unless continuous
I II
- increase or defeat mechanical
!
jam level.
- turn on cyclic overload switch or
defeat memory_
- use run curve with longer trip times
- increase maximum load control
setting.
- consult Instruction Manual
Section 310
- use emergency restart to dm-
charge memory before test
I
- decrease maximum load control
setting
- allow motor to cool.
- disconnect RTD wires running
from relay to terminals in
switchgear.
- shield wires. check for correct
connections. reroute away from
nmse sources
- place jumper across unused
thermistor terminals.
- check relay switch settings
[Manual Section 31 Di
I
I
I
- increase G/F trip level
I
- increase G/F time delay
- twist ground fault wires together
I
and route away from heavy
· , current conductors. _J
, All relay ~n-d1-ca-to~~1ft ___ n_o_c_o_nt_ro_l _po_w_e_1 ____ --+-_-c-he_c_k-fo-1-su_p_p_ly-vo-lt-a-ge_a_t__ !
-,. L. . -· .
______ I
- control power applied to wrong
1erm111als
35
terminals 15 and 16 I
- damaged companents. return relay .
for repair. .
Courtesy of NationalSwitchgear.com