TROUBLE SHOOTING THE MARKET FORGE CO. CONTACTOR
The following table lists the major causes of trouble encountered with contactors and the suggested remedies:
CONTACTS
TROUBLE
CAUSE
REMEDY
Contactor Chatter
1. Low Voltage
2. Defective or incorrect coil.
1. Check voltage condition. Check momentary
voltage dip during starting. Low voltage
prevents magnet sealing. Check coil
voltage rating.
2. Replace Coil, rating of coil must match the
line voltage.
Welding or Freezing
1. Abnormal inrush of current.
2. Low Voltage preventing mag
net from sealing.
3. Short Circuit.
1. Check for grounds or shorts in system.
2. Correct voltage condition.
3. Remove short fault and check to be sure
fuse or breaker size is correct.
Short Contact
Button Life
and/or overheating
of contacts
1. Filing or dressing.
2. Interrupting excessively high
current.
3. Discolored contacts caused
by insufficient contact pres
sure, loose connections, etc.
4. Dirt or foreign matter
on contact surface.
5. Short Circuit.
1. Do not file silver tips. Rough spots or dis
coloration will not harm tips or impair their
efficiency.
2. Check for grounds, shorts or excessive
current.
3. Check contact carrier for deformation or
damage, clean and tighten connections.
4. Clean w ith Acetone.
5. Remove fault & check to be sure fuse or
breaker size is correct.
COILS
TROUBLE
CAUSE
REMEDY
Open Circuit
1. Mechanical damage.
2. Burnt-out coil due to over-
voltage or defect.
1. Handle and store carefully. Do not handle
coils by the leads .
2.
Replace coil.
Overheated Coil
1.
Over-voltage or high ambient
temperature.
2.
Wrong coil.
3.
Shorted turns caused.
4.
Under voltage, failure of
magnet to seal in.
1. Check application and circuit.
2. Check rating (voltage and frequency) if
incorrect, replace with proper coil.
3. Replace coil.
4. Correct system voltage. Install new coil.