DC motor equalizer windings burn !

Hi
Do you know what happening can be cause a severe burn in EQUALIZER WINDINGS in a dc motor?
It shows a high current passed from a wire of equalizer windings.
Motor Specifications:

DC Traction motor
530 Kw
600 Vdc
2000 rpm

Thanx

 

[THooper]

If just one of the equalizers are burnt, It is more than likely a poor connection at the commutator riser.

If all the equalizers show signs of heat, overload, or insulation breaking down, it could possibly be a couple problems.
1. (MOST COMMON)Insulation breakdown.
2. (RARE, but possible) Too small of
wire used when rewind was performed last?



Kind Regards,
motorhead1

 

There is just one of the equalizers are burnt.
Please let me know, how a poor connection at the commutator riser can be cause this problem?

Thanx motorhead1 for your kindness.

 

[THooper]

A poor solder joint or tig weld connection, the more severe the stresses and the higher the joint current density, the less suitable solder will be. However, in most applications, provided the joint area is sufficient and the process properly controlled, either method is acceptable at the riser.

The disadvantage of soldered connections are that severe short time overloads cause some of the solder to melt. The connection then does not have sufficient area to safely carry the current, and the joint becomes a hot spot.

A couple concerns of a bad solder joint are electrical resistance and mechanical strength within the joint of the riser, it would be the same problems if we were looking at a loose terminal connection at a power supply source.

1. excessive heating
2. the line of current unbalanced.
(higher current)
The overheating will only get worse until insulation breakdown occurs and the end result of premature winding failure....