Problem
Contacts
Contacts Chatter
Welding
Coils
Open
Circuit
Overheated
Coil
Failure to Drop-Out
Cause
Low Voltage
Abnormal Inrush Current
Insufficient Contact Pressure
Foreign Matter Preventing Contacts
from Closing
Foreign Matter Preventing Proper
Latch Motion
Short Circuit
Excessive Inrush Current
Filing or Dressing
Foreign Matter on Contact Surface
Mechanical Damage
Incorrect Coil
Low Voltage
Wrong Coil or Wrong Connection
Mechanical Obstruction
Coil Open or Overheated
Sticky Substance on Pole Faces
Release Coil not Energized
Contacts Welded
Corrective Action
Check supply voltage, especially during starting. Check coil voltage rating.
Increase voltage or change coil rating as required.
Check for grounds, shorts or excessive load current.
Replace contacts and springs, check contacts for abnormal wear or damage.
Check supply voltage to coil, especially for momentarydip during startup.
Clean contacts with LPS CFC-Free Electro Contact Cleaner.
Contacts used at low currennt and voltage should be cleaned with Freon.
Clear latch mechanism of foreign matter.
Check that latch mechanism moves properly.
Remove fault and check to be sure fuse or breaker size is correct.
Use next larger size contactor.
DO NOT FILE SILVER CONTACTS. Rough spots or discoloration will not
harm contacts or impair their efficiency.
Check for grounds, shorts or excessive currents. Use next larger size contactor.
Replace contacts and springs, check contacts for abnormal wear or damage.
Clean contacts with LPS CFC-Free Electro Contact Cleaner.
Take steps to reduce entry of foreign matter into enclosure.
Remove fault and check to be sure fuse or breaker size is correct.
Clean and tighten.
Replace with new coil. Handle and store new coils carefully.
Check coil rating and replace with correct coil.
Check coil marking and wiring.
With power off, check for movement of armature, contacts and latch
mechanism.
Replace.
Clean pole faces with LPS CFC-Free Electro Contact Cleaner.
Check coil, coil circuit or length of leads from supply voltage to coil.
Coil may be open or lead length is excessive.
Replace unit.
See welding under contacts.
TROUBLESHOOTING
These instructions do not purport to cover all details or variations in equipment nor to
provide for every possible contingency to be met in connection with installation,
operation, or maintenance. Should further information be desired, or should problems
arise which are not covered sufficiently for the purchaser’s purposes, the matter should
be referred to the local Siemens Sales Office.
8
Weak Contact Pressure
Low Voltage Preventing Magnet
from Sealing
Short Contact Life
or Overheating
Interrupting Excessively High Currents
Short Circuit
or Ground Fault
loose Connection in Power Circuit
Magnetic and
Mechanical Parts
Failure to Pick-up and Seal
Worn or Rusted Parts Causing
Binding
Check system voltage and voltage dips during starting
The contents of this instruction sheet shall not become part of or modify any prior or existing
agreement, commitment or relationship. The sales contract contains the entire obligation of
Siemens. The warranty contained in the contract between the parties is the sole warranty of
Siemens. Any statements contained herein do not create new warranties or modify the existing
warranty.
Siemens Industry, Inc. 5300 Triangle Parkway, Norcross, GA 30092
A5E49381767A
