Page 372 - Electrician 1st year - TT - Malayalam

Table 1

Trouble Shooting Chart
Problem Possible cause Corrective action

Mixer does not run. a) Overload trip might have tripped. a) Reset the overload relay and advice the customer
not to overload the mixer in future.
b) No power at the outlet. b)If the mixer is running in your shop but not
running a t the customer’s house ask the
customer to get the socket repaired.

c) Defective power cord or plug. c)Test, repair or replace the power cord/plug.
d) Locked shaft. d) Unplug the supply and try to rotate the shaft
by hand. Clean t he bearings; lubricate t he
bearings as advised by the manufacturer. If the
shaft is still tight, recondition or replace the
bearings. The shaft might have got bent.
Replace the shaft or armature assembly.

e) Worn out brushes. e) Replace the brushes and loose springs
f) Open circuited. f) Check the field and armature windings.
If found defective get it rewound or replace.

Blows fuse when a) Shorted power cord. a) Replace the cord.
switched on.
b) Locked shaft. b) As in ‘d’ above.

c) Defective armature or field coils. c) Test the windings for short. If short is found,
rewind or replace.
d) Poor insulation resistance. d) Check, test and repair.

e) Low capacity fuse. e) Check the capacity of the fuse against the
mixer rating. Replace if required.
Mixer runs but a) Overloading of mixer. a)Bring down the load in the mixer or advise the
b e c o m e h s . t o c u o t s m g o t r e g i h a r o f o h c r e a p a y t i c m x i . r e
b) Time rating of mixer is exceeded. b) Check the duration the mixer is switched on by
the customer and compare with the mixer
rating. Advise accordingly.
c) Bent shaft and rotor is rubbing the c) Check, repair or replace if required.
stator.
d) Improper coupling. d) Check, repair or replace if required.
e) Shorted winding. e) Check, test and rewind if required.

Bad sparking a) Struck or worn out or loose a) Check, reshape the brushes, replace the
at motor brushes. u r b s h e . s s n i r p g r o s reposition the brushes for proper
tension.
b) Pittings or uneven commutator b) Use sand paper or turn the commutator on a
surface. lathe.

352 ഇലക്്ടട്്രരീഷ്്യൻ (NSQF - പുതുക്തിയ 2022) േതി. സതി . റവണ്തി എക്്ടസതിർസസസ്ട 1.11.96