Motor Terminations

Status
Not open for further replies.

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
comments concerning 480V only - zip to 200hp

This is the spec that most of my customers use:

ring tongue lugs (uninsulated-crimped if not already on the T leads)
SS nuts and capscrews - generally no washers, cut short so they only stick out a thread or so
fiberglass tape (27?)
130
88 or 33

The fiberglass tape prevents a lot of evils. Makes removal/repair a lot easier.

You guys are getting addictive - and I've got a paying job this week

Later

ice


For many years in the trade many of use followed that procedure except we used 2510 VC tape rather than 27 Fiberglass. To me, if it's a taped connection wheather rings wth screws&nuts or wirenuts, the VC or Fiberglass tape is a necessity for strength and future removability.(nothing worse to remove than a split bolt with rubber tape).
More recently the most common thing I see is the NSI Polaris motor lead connectors
I notice 3M has this product for those interested:https://www.youtube.com/watch?v=nrdYO-_gjW8
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
For many years in the trade many of use followed that procedure except we used 2510 VC tape rather than 27 Fiberglass. To me, if it's a taped connection wheather rings wth screws&nuts or wirenuts, the VC or Fiberglass tape is a necessity for strength and future removability.(nothing worse to remove than a split bolt with rubber tape).
...
I have never used VC or fiberglass tape as the first layer. I have never had any issue removing the 130C where it has been correctly installed..that is wrapped sticky side out.

I hate when they have used VC with adhesive...that always seems to leave a gooy mess when you take the tape off.
 

SceneryDriver

Senior Member
Location
NJ
Occupation
Electrical and Automation Designer
I use these for smaller motors with good success. Vibration proof as far as I can tell, removable, and quick to install.

http://www.mcmaster.com/#6878k97/=w32ji8

The size shown will do 10ga splices. McMaster also has a smaller version as well for little motors.


I've also used these:

http://www.mcmaster.com/#7618k672/=w32knj

If you have room in the peckerhead, "Eurostrip" terminal blocks are the way to go. When used with crimped wire ferrules on the motor leads, they can be successfully put together and taken apart many times without issue.



SceneryDriver
 

Fulthrotl

~Autocorrect is My Worst Enema.~
When splicing together the motor leads in the peckerhead, if the leads are 10 wire, is it acceptable to use regular wire nuts and then tape with rubber tape and super 33? Is there an actual code that says rubber tape must be used for splicing motor leads in a peckerhead?

Thanks

i've done it that way. use good wire nuts, that
can be taped up and will seal.

if i've got to do bolted connections, i hypress lugs
on, bolt them togeather with short nuts and bolts,
so there isn't an issue with a protrusion.

then varnished cambric, for dielectric strength,
self vulcanizing rubber tape for cushioning the insulation,
and scotch 33+ for the top layer.

little motors, i use the wago lever nuts shown earlier.
good up to #12, and they do NOT come loose.

i just made up a bunch of eurodrives,and the bosch motors
have a really nice terminal block inside. set the jumpers for
the voltage, hypress on some lugs, and you are done.

bring your metric stuff. all the hardware is metric.
 

tom baker

First Chief Moderator
Staff member
Attached is a picture of a split bolt used on a 100 hp fire pump motor. I had to pick out all the rubber and re-terminate. Took hours.
Opps sorry I will attached the picture later.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
This amazes me. :D

It must be as rare as NM in a multistory commercial building to you.
Just not something that is done in my area of work...mostly industrial, at least not around here. Even when I was doing commercial service calls, I never found a motor connected using split bolts. If it wasn't ring terminals and bolts, it was wire nuts.

I think just like regional "slang" terms, there are a lot of installation practices that are also regional.
 

big john

Senior Member
Location
Portland, ME
All our motor guys use crimp-lugs and bolts and then tape/heat-shrink, and they're pretty die-hard about it.

There's a sound argument about the permanence of this type of connection for making up the winding groups because those will rarely if ever be separated in the field.

However, I've always wondered how much of this is just termination voodoo from a time when no better options existed. I am very tempted to say that Polaris blocks of the right stranding class would work fine for doing field terminations. Unfortunately, we'd have to take a risk to prove it.
 
Status
Not open for further replies.
Top