ABB DC Machines DMI User Manual

44
Faults and remedies
Electrical
Fault Possible cause Remedy
Motor will not start at no load No armature voltage Check supply
Armature coils burnt out or short-
circuited
Clear short-circuit (generally
only possible in specialist’s or
manufacturer’s workshop)
Brushes not making proper contact Check pressure and position of
brushes, replace worn brushes
No excitation voltage Check supply
Open circuit in field winding Remedy open circuit
Interturn short-circuit in the armature
winding
Repair in workshop
Short-circuit between commutator
segments
Check commutator and eliminate short
Motor will not accept load Overload Check current input and eliminate
overload
Voltage decreasing Check supply
Motor overspeeding and hunting
under load
Brushes displaced from neutral zone in
opposite direction to rotation position
Set brush-bracket to mark under load
Fault in field circuit Eliminate fault
Auxiliary series winding wrongly
connected
Check connection and correct
Generator not supplying voltage Open circuit in excitation circuit Check excitation circuit for fault
Short in main circuit Check circuit
Open circuit or interturn short-circuit in
rotor winding
Check winding for open circuit or
interturn short-circuit
Voltage drop on unregulated
generator on load is too high
Speed reduction of drive too great Set drive to normal speed, drive too
weak
Incorrect brush setting Check brush setting, correct
Overheating in operation Overload Check voltage and current, eliminate
overload
Insufficient cooling air Improve cooling
Temperature of cooling air or water too
high
Clean internal and external air
passages
Insufficient cooling water Check flow rate of cooling water,
increase if necessary
Cooler or filter dirty Clean cooler, change filter

ABB DC Machines DMI Specifications

General

Brand	ABB
Model	DC Machines DMI
Category	Engine
Language	English