Echo Electric Motors

Motor Protec on - con nued Any Size Motor ▪ Any Applica on ▪ Expert Protec on Motor Accessories & Power Transmission Products

Common Causes of Relay Indications and Possible Corrections

Relay Indica on

Likely Cause

Correc on

Overvoltage Undervoltage Excess flow Bad bearings

Correct voltage problem at source Check wiring; contact u lity Review pump spec / applica on

Overcurrent

Replace bearings Clean out pump Clean out pump

Foreign material in pump

Jammed pump Restricted flow

Correct flow restric on

Undercurrent

Lack of liquid to pump

Shut down un l liquid is restored Repair mechanical components

Broken sha coupling or belt

Bad wiring

Examine and correct

Current Unbalance

Unbalanced power input Bad regula on from u lity Bad regula on from u lity

Reconnect single-phase loads to balance phases

Overvoltage

Correct voltage problem at source Correct voltage problem at source

Undervoltage

Wiring problem Broken wire Bad contactor

Examine and correct

Repair wiring

Single-Phase

Replace contactor

Blown fuse / u lity failure

Replace fuse / contact u lity

Phase Reversal

Miswiring upstream in electrical system

Exchange two phases at input to pump power panel Have motor tested and re-varnished if feasible

Small defect in insula on

Ground Fault

Contamina on in wiring or junc on boxes

Clean out contamina on Replace contactor / contacts

Faulty contactor

Contactor Failure

Bad connec ons on load side

Repair connec ons

Unblock air ven la on to motor cooling fins and general area. Clean motor of dust and debris.

Poor ven la on

Overtemperature

Unbalance condi on

See "current imbalance" above

Bearing fric on

Lube or replace bearings

Load exceeds motor's capability

Inspect the load to determine if it has changed

Jam

Check for mechanical jams, failed bearings, or other problem that would prevent the motor from turning.

Mechanical jam

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