Insulation for large crimps?

[Max1882]

Hi all, new to the forum so go easy!Ha......At work we have a pump with a 3 phase motor attached.....the wires that come from the winding are 50mm....The lid with the incoming flex has 70mm tails.....yes i know this is wrong but i was going to use 70mm through crimps and just crimp it a bit tighter on the side with the 50mm tails.......My problem is how can i insulate these crimps? 2/3/4 layers etc of heat shrink? Someone has mentioned self amalgamating tape? or can you get more heavy duty sleeving etc? BTW it'sa74kw motor pulling 140 amps....Any help welcome.....Thanks....

Max

 

[Morgan keith]

Yeah think heatshrink is probably the best thing for it. The adhesive lined waterproof heatshrink is probably a better choice than the normal stuff

 

[Beavstro]

Well as a suggestion, you method of crimping is a bit cowboyish, if you don't want to seek out the correct crimps I would use a 70mm2 ring crimp and a 50mm2 ring crimp and bolt them together, and yes, some good quality heat shrink.

 

[Beavstro]

A quick google search has found the perfect crimp...
https://www.electriciansforums.net/attachments/utiliux-pdf.120424/

 

[Marvo]

You get some very heavy duty heat shrinks that you'd only need a single covering, They can be expensive, try Farnell or RS Components.

 

[Deleted member 72666]

Or you could try: Silweld
My local wholesaler stocks these in various colours.

 

[Max1882]

Well as a suggestion, you method of crimping is a bit cowboyish, if you don't want to seek out the correct crimps I would use a 70mm2 ring crimp and a 50mm2 ring crimp and bolt them together, and yes, some good quality heat shrink.

I know it's not ideal but obviously ring crimps with a nut and bolt through aren't exactly ideal for trying to get some heat shrink round? IMO?

 

[Engineer54]

How are you going to crimp a bit tighter on the side of the 50mm cable?? Die's are die's and will only crimp down to what is required for a 70mm cable!! So what method are you intending to use, to get a 70mm crimp to securely crimp a 50mm cable??

Do the job correctly use a reducing 70mm-50mm through crimp connector, they are available though maybe not from all wholesalers! Cover with good quality thick wall heat shrink or amalgamating tape...

 

[Knobhead]

Is this in the motor terminal box? A motor that size will have six winding ends to a connection block.

I don’t believe a word of this.

 

[Engineer54]

Is this in the motor terminal box? A motor that size will have six winding ends to a connection block.

I don’t believe a word of this.

Seen quite a few (mainly Yank) motors, that just have the winding ends to connect on too.

 

[Knobhead]

With no terminal block?

The usual reason for no terminal block is its been smashed.
Submersible pumps will have a flexible cable to be terminated remotely.

It would be interesting to see a photograph.

 

[Marvo]

Many of the submersible pumps we come across in mining applications have an IP69K rated plug and socket built into the body of the pump.

I'd also say unequal CSA wires in the same ferrule is not a good idea. Beavstro's idea of bolted ring lugs works for me but I can't help thinking in a motor of this size there'd be space to mount a terminal block somewhere.

 

[Engineer54]

With no terminal block?

The usual reason for no terminal block is its been smashed.
Submersible pumps will have a flexible cable to be terminated remotely.

It would be interesting to see a photograph.

Next time i see one, i'll get a photo of it for you...