Melted motor terminal post?

[-Matt]

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?

 

[-Matt]

Similar to this;
LOVATO 11RF180 THERMAL OVERLOAD RELAY 120-200A RANGE (600427) | eBay - https://www.ebay.co.uk/itm/292991963327

That looks like it! I was wondering if the base was a generic part the overload connects to, but looks like its all 1 unit.

It doesn't even look like the O/L is used. Dependent on the type of soft start, the O/L protection may well be built into that.

Have you measured that all of the windings are balanced, through the cable to the motor?

If they are, then yes the SS is likely kaput.

Its an ABB soft start which does not have overload protection, the L3 has been bypassed from the overload.

The motor is balanced.

So looks like the soft start is ----ed, in which case I am going to get a 110KW soft start.

Im thinking of going for one of the Schneider digital soft starts which has built in overload:

https://uk.rs-online.com/web/p/products/7106451/?cm_mmc=aff2-_-uk-_-octopart-_-7106451

Going to have a chat with my wholesaler in a bit to see how fast he can get one and for a better price than RS!

 

[Bobster]

So looks like the soft start is ****ed, in which case I am going to get a 110KW soft start.

Im thinking of going for one of the Schneider digital soft starts which has built in overload:

https://uk.rs-online.com/web/p/products/7106451/?cm_mmc=aff2-_-uk-_-octopart-_-7106451

Going to have a chat with my wholesaler in a bit to see how fast he can get one and for a better price than RS!

What is the motors duty cycle? (How many times an hour does it start and stop?).

Does it start under fully loaded in normal situations?

You may need to look at a SS the next frame size up 132KW. Either of these will not fit in the existing control panel looking at the size.

If you start installing a new control panel, you're going to take responsibility for the design and safety of the machine. Just to let you know this.

This will involve a CE declaration.

 

[-Matt]

What is the motors duty cycle? (How many times an hour does it start and stop?).

Does it start under fully loaded in normal situations?

You may need to look at a SS the next frame size up 132KW. Either of these will not fit in the existing control panel looking at the size.

If you start installing a new control panel, you're going to take responsibility for the design and safety of the machine. Just to let you know this.

This will involve a CE declaration.

Thanks, Its pretty much started once a day and then just runs all day.
Its always started empty, so the motor can spin freely.

TBH I don't think I will get any 110KWn soft start to fit in the existing enclosure, so its going to need a bigger enclosure anyway.

 

[Bobster]

The sizing of SS catches a lot of inexperienced people out, but if only starting once an hour empty you should be ok with a 110KW frame size.

You will also likely need semi conductor fuses to protect the SS to meet manufacturers installation instructions.

I haven't seen the application, so I can't offer any in depth advice.