Cover - Train Lighting - Indian Railways Institute of Electrical ...

3.6 TROUBLE SHOOTING INSTRUCTIONS FOR 4.5 KW ERRU
Sr. Type of
No. Defects
1. Regulator
output is less
(or) no
generation.
Probable Cause Check Remedy
a. HRC fuse
blown.
b. Field fuse
blown.
c. A loose
connection in the
field winding (or)
open (or) short
Ckt.
d. Field winding
is earthed.
e. Phase winding
may be open
(or) short ckt
(or) earthed.
f. 3Φ bridge
rectifier may be
open (or) short
ckt.
Check Fuse If fuse blown,
change the fuse.
Check Fuse If fuse blown,
change the fuse.
Remove the field If a connection
connection from between two field
Reg. Check the field is broken, join
connection in the the two leads by
Alternator in brazing of the
between the field leads. If field coil
winding and check defective,
the continuity of Alt remove the coil
field cables. If carefully and
continuity is OK, replace it with
check the resistance the new field coil.
of field coil.
The resistance of
new field coil at
20 o C is 4.0
±0.5Ω.
Check the megger
value of the filed
coil.
Check the leads,
continuity &
resistance of the
phase winding.
Check the 3Φ
bridge rectifier by
using multimeter,
after removing
the bus bars from
3Φ bridge
rectifier.
If megger value
is less than one
MΩ, send the Alt
to shop for
proper attention
of field coil.
If the leads are
open, braze the
leads with coil
termination. If
the phase
winding is short
(or) earthed,
send the Alt to
shop
for
rewinding.
Replace the 3Φ
bridge rectifier,
if found
defective.
GENERAL SERVICES : TRAIN LIGHTING 39