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TD03309002E
Technical Data
Page
6
Effective: January 2005
Storage, Handling,
Installation and
Maintenance of Controllers
Table 3. Contactor Troubleshooting Chart, Continued
Defect Cause Remedy
Contacts, continued
Short Contact Life or
Overheating
Filing or dressing
DO NOT FILE SILVER CONTACTS.
Rough spots or discoloration will not harm
contacts or impair their efficiency.
Interrupting excessively high currents Install larger unit. Check for grounds, shorts or excessive motor currents.
Excessive jogging Install larger unit rated for jogging service.
Weak contact pressure Replace contacts and springs. Check contacts for abnormal wear or damage.
Foreign matter on contact surface Clean contacts with freon. Take steps to reduce entry of foreign matter into
enclosure.
Short circuit or ground fault Remove fault and check to be sure fuse or breaker size is correct.
Loose connection in power circuit Clean and tighten.
Sustained overload Check for excessive motor load current or install larger unit.
Magnetic and Mechanical Parts
Noisy Magnet Broken shading coil Replace magnet and armature.
Rust or dirt on pole faces Clean with freon.
Low voltage Check system voltage and coil voltage rating.
Misalignment or mismating of magnet pole
faces
Realign or replace magnet assembly.
Failure to Pick Up and
Seal
Low voltage Check system voltage and voltage dips during starting.
Wrong coil or wrong connection Check coil marking and wiring.
Mechanical obstruction With power off, check for free movement of armature and contacts.
Coil open or overheated Replace.
Failure to Drop Out Sticky substance on pole faces Clean pole faces with freon.
Voltage not removed Check coil circuit or length of leads from supply voltage to coil. May be
excessive.
Worn or rusted parts causing binding Replace unit.
Contacts welded See
Welding
under contacts.
Coils
Open Circuit Mechanical damage Replace with new coil.
Handle and store coil carefully.
Overheated Coil Over-voltage or excessive ambient
temperature
Voltage should not exceed 110% of coil rating. 40°C is maximum ambient.
Incorrect coil Check coil rating and replace with proper coil.
Shorted turns caused by mechanical damage Replace coil.
Under-voltage/failure of magnet to seal in Correct system voltage. 85% of rated coil voltage is minimum allowable.
Dirt or rust on pole faces Clean pole faces with freon or equivalent solvent.
Mechanical obstruction With power off, check for free movement of armature and contacts.
Overload Relays
Nuisance Tripping Sustained overload Check for motor or electrical equipment grounds and shorts, as well as excessive
motor currents due to overload. Check motor winding resistance to ground.
Loose or corroded connection in power circuit Clean and tighten.
Loose heater screws Clean and tighten.
Incorrect heater Check heater sizing and ambient temperature and replace with correct heater.
Failure to Trip Relay previously damaged by short circuit Replace relay and heaters.
Incorrect heater Check heater table and replace with correct heater.
Relay contact welded or not in series with
contactor coil
Use manual trip to check circuit. Check circuit for a fault and correct condition.
Replace entire relay as required.
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