Discuss Melted motor terminal post? in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

-Matt

-
Reaction score
152
Customer has this 110KW (converted to 55KW) motor powered via a generator.

They had a problem with the generator cutting out on startup showing overload fault.

Having investigated this issue, along with the motor overload having been bypassed!! (will be rectifying this!)

when I took the cover off the motor I noticed the nylock nut had melted its plastic with signs of overheating.

whilst removing the link bar to test the coils, I found the whole terminal post had melted out of the insulating section. and pretty corroded terminals.

My assessment is a poor connection on the terminal posts .

The coils seem ok.

Im trying to get a motor expert to come out and give his opinion and repair option. however having trouble getting someone out quickly, and customer needs this running ASAP.

Can anyone think of a temporary or permanent, safe fix?
I guess it really needs new terminal block and posts?

What do you guys think?

Melted motor terminal post? IMG_2239.JPG - EletriciansForums.net


Melted motor terminal post? A0D60D25-C534-4971-9122-19DD222C1AAE.JPG - EletriciansForums.net
 
gorilla snot glue. :p:p:p
 
You may expect one post to fail for some reason but to me they are all showing signs of overheating. Get a specialist to look at it and don't attempt an ad hoc repair.
 
Ulimately a new block.
They're fairly standard, has the customer got an old / spare motor around?

But, you'll need a new crimp on the ends coming from the windings (or clean the existing up).

As W10 above, they all look to have damage, so clean up all the ring crimps from the windings and nuts /screws.
And the supply cables.

Then new ring crimp onto the supply cable, use a new /clean screw / nuts and washers to the damaged one.
Heat shrink over the joint if you've got any big enough (put on firts of course) tie wrap the joint away from the block so it doesn't bounce around.
 
I would want to know why they have ended up like that, yes a new block can be fitted but long term do you end up in the same situation or worse.
 
Hmm - someone has troubled themselves to bypass the thermal overload and now terminal plate has melted. Is the motor running overloaded or am I reading too much into this?

I suspect it was a temporary bodge that was never rectified, its been like that any least a year.

I actually measured the running currents of this motor a few weeks ago (with aim of getting onto grid supply) and it varied from around 50-100A, which FLC of 97A for a 55KW motor seemed ok.


You may expect one post to fail for some reason but to me they are all showing signs of overheating. Get a specialist to look at it and don't attempt an ad hoc repair.

Hopefully a specialist will get out tomorrow.

How has it been converted to 55kw.

That is a question I asked, but they don't know was the answer...
 
If they were solid connections, I find it difficult to understand why a terminal would burn out like that before a winding going down.
Looks like a complete rewind and terminal block, who knows the internal damage done. How do the windings read?
 
There isn't a Variable speed drive somewhere is there?

Nope, from soft starter (55KW) direct to motor.

However im not overly familiar with soft starters and did note the motor was wired in star, I would have expected delta?


If they were solid connections, I find it difficult to understand why a terminal would burn out like that before a winding going down.
Looks like a complete rewind and terminal block, who knows the internal damage done. How do the windings read?

I did wonder if it was a loose connection on the star link connection?

However now wondering if it should have been in delta?

The readings were pretty low, all around 0.5ohm, which did seem low for a motor this size?


Good question the only way I can think of is that they sent it to get rewound to 55kW. Bit expensive though.

Yes I couldn't work this out, im sure it would have been cheaper to just get a 55KW motor!

But its apparently been in this configuration for several years...
 
Continuing the miss marple theme...has any water been running off that truss section?
 
And is it getting any cooling through the vent , or is it all gunged up with the crud we can see on the outside.
 

Reply to Melted motor terminal post? in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock