# Question on motor termination



## Chops146 (Aug 26, 2018)

Couldn't you use a 10-12 with a ¼" hole as well and ¼" hardware? It would look cleaner IMO.


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## Navyguy (Mar 15, 2010)

I have never actually used them, but I have heard good things at trade shows about them.

Cheers
John


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## SpaceMonkey (Sep 19, 2018)

Looking at 3M and T&B catalogs, I am seeing various stud sizes for standard 10-12ga terminals, yeah 1/4" will work better.


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## SpaceMonkey (Sep 19, 2018)

Navyguy said:


> I have never actually used them, but I have heard good things at trade shows about them.
> 
> Cheers
> John


Thanks for the input, but I'm pretty well set on using crimp ring and bolts.


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## glen1971 (Oct 10, 2012)

SpaceMonkey said:


> Terminating a 30HP motor, and want to use the ring and bolt method. Unfortunately most everyone where I work would only use wirenuts for this, so I wanted to get some help from you guys.
> 
> Feeder is 8awg THHN, leads in the peckerhead are either 10-12awg. Now I've used a lot of the yellow-blue-red crimp terminals before, but anything 8awg or bigger the crimp lugs(T&B Blackburn) get far larger than the smaller yellow insulated crimp terminals that I will use on the motor leads.
> 
> Is there any issue with using a 8awg crimp lug with a .25" hole bolted to a smaller yellow crimp terminals(10-12awg) that has a 3/16" hole?


Change the motor leads to 10RC14 crimp lugs (1/4" hole), use #8 1 hole crimp lug with a 1/4" bolt, and 1/4" x 3/4" bolts and hardware.. Tape and/or boot to finish it up and Bob's your uncle..


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## paulengr (Oct 8, 2017)

Best to match hole size to bolt. That way there is better contact and less sloppy loosening that can lead to failures.

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## SpaceMonkey (Sep 19, 2018)

Thanks a bunch guys, I'm doing this specifically for less chance of failure so I might as well do it right!


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## splatz (May 23, 2015)

glen1971 said:


> Change the motor leads to 10RC14 crimp lugs (1/4" hole), use #8 1 hole crimp lug with a 1/4" bolt, and 1/4" x 3/4" bolts and hardware.. Tape and/or boot to finish it up and Bob's your uncle..


Just curious, wondering why not a shorter bolt?


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## gpop (May 14, 2018)

SpaceMonkey said:


> Terminating a 30HP motor, and want to use the ring and bolt method. Unfortunately most everyone where I work would only use wirenuts for this, so I wanted to get some help from you guys.


Most company's have a rule about wire nuts and motor terminations. Where i work any thing over 20hp should not be wire nutted. As we have a lot of motor over 20 we stock a lot of different styles of connectors. We avoid rings if possible as they are a pain to use and the ring will probably have to be cut off if the motor is un-wired. (we un-wire a lot of motors so the wrenches can move the motor out of the way to service gearboxes etc.)

If the other guys are using wire nuts it might be a good idea to ask why. If it just laziness then i would go with a ring if that's all i had on hand but they might have another reason that's worth considering.


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## glen1971 (Oct 10, 2012)

splatz said:


> Just curious, wondering why not a shorter bolt?


I couldn't remember offhand if a 1/2" bolt would be long enough with the crimps, washers and a nut so said 3/4". I used to carry both 1/2" and 3/4" just in case the splice needed one or the other..


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## JRaef (Mar 23, 2009)

The _*only*_times I have ever seen motor connections come loose is when they were done with wire nuts... just sayin'...


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## bill39 (Sep 4, 2009)

Boy, what a can of worms. Discussing the “right” way to terminate motor leads can lead to fisticuffs. It’s almost as hard as getting everybody to agree that the earth is flat.


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## SpaceMonkey (Sep 19, 2018)

So a couple more question on the fine details...

For a 1/4" bolt with 1/4" stud holes, is it necessary to use washers?

What type of lock nuts do you guys recommend?


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## glen1971 (Oct 10, 2012)

SpaceMonkey said:


> So a couple more question on the fine details...
> 
> For a 1/4" bolt with 1/4" stud holes, is it necessary to use washers?
> 
> What type of lock nuts do you guys recommend?


I've always done it so that the nut and/or bolt head don't dig into the ring connector and cause a sharp spot... I also use lock washers (flat washers with a slit in them and slightly twisted - just so everyone knows what kind of washers I mean)... First wrap of tape is 88, sticky side up..


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## gnuuser (Jan 13, 2013)

glen1971 said:


> Change the motor leads to 10RC14 crimp lugs (1/4" hole), use #8 1 hole crimp lug with a 1/4" bolt, and 1/4" x 3/4" bolts and hardware.. Tape and/or boot to finish it up and Bob's your uncle..



but use brass if possible! steel nuts and washers can act as a solid core transformer and build enough heat to melt under a high current load
you can use steel bolt but need brass washer and nut.


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## glen1971 (Oct 10, 2012)

gnuuser said:


> but use brass if possible! steel nuts and washers can act as a solid core transformer and build enough heat to melt under a high current load
> you can use steel bolt but need brass washer and nut.


Never heard of that before, but makes sense (non-ferrous I assume).. Haven't had to replace one that I've done that melted (knock on wood)..


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## Instrumentation (Mar 11, 2018)

bill39 said:


> Boy, what a can of worms. Discussing the “right” way to terminate motor leads can lead to fisticuffs. It’s almost as hard as getting everybody to agree that the earth is flat.



I'm sitting in the split bolt sections.


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## sparkiez (Aug 1, 2015)

JRaef said:


> The _*only*_times I have ever seen motor connections come loose is when they were done with wire nuts... just sayin'...


This brought up an interesting thought of mine. The only time I've ever seen wirenuts come loose is when they were improperly installed. People like to trim off like 1/4" of wire at the end and try to make a connection. I was taught that they are "wire nuts" not "insulation nuts".


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## splatz (May 23, 2015)

One thing I thought of going back to @SpaceMonkey 's original post - why use an insulated terminal on the smaller one? In my opinion the uninsulated crimp terminals make a better connection anyway since you're not crimping through plastic / nylon. You're going to have to tape the whole thing up anyway, it's a little less bulk.


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## sbrn33 (Mar 15, 2007)

I would use a small split bolt if at all possible. I would not use Polaris connectors any more. Learned that lesson. Any crimp is suspect in my book.


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## bill39 (Sep 4, 2009)

sbrn33 said:


> I would use a small split bolt if at all possible. I would not use Polaris connectors any more. Learned that lesson. Any crimp is suspect in my book.


What happened with the Polaris connectors? Although I've never used them they seem foolproof if installed properly.


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## JRaef (Mar 23, 2009)

Instrumentation said:


> I'm sitting in the split bolt sections.



Me too. I busted too many knuckles doing split bolts in tight spaces to give up and let people get away with something easier... You all have to pay your proper dues!
:vs_mad:
And get the heck offa my lawn while you're at it! :wheelchair:


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## paulengr (Oct 8, 2017)

bill39 said:


> What happened with the Polaris connectors? Although I've never used them they seem foolproof if installed properly.




The insulation rubs through over time. Also they gall pretty easy so if you try to reuse often you don’t get a properly torqued connection.


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## micromind (Aug 11, 2007)

sbrn33 said:


> I would not use Polaris connectors any more. Learned that lesson.


Same here, I've seen far more Polaris connectors burn up the everything else combined. Even the ones designed for fine stranded wire.


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## SpaceMonkey (Sep 19, 2018)

splatz said:


> One thing I thought of going back to @SpaceMonkey 's original post - why use an insulated terminal on the smaller one? In my opinion the uninsulated crimp terminals make a better connection anyway since you're not crimping through plastic / nylon. You're going to have to tape the whole thing up anyway, it's a little less bulk.




Only reason is that in my area the insulated terminals are much more available(was actually able to find some with the 1/4” stud I was looking for). Also my nice ratcheting crimper is for insulated terminals. I’ll probably see if I can get a set of dies for uninsulated eventually


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## SpaceMonkey (Sep 19, 2018)

I have another rookie question...

Can you only use a split bolt on an “in-line” connection or can you use it with both conductors entering the bolt from the same side?


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## cad99 (Feb 19, 2012)

SpaceMonkey said:


> I have another rookie question...
> 
> Can you only use a split bolt on an “in-line” connection or can you use it with both conductors entering the bolt from the same side?
> 
> ...




Can be used both ways. Where I work 4160 motors are crimped and bolted. 480v are split bolts. Use split bolts in this fashion in the pecker heads. Then used inline if we have to add length/refeed after an incident. 


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## Chops146 (Aug 26, 2018)

SpaceMonkey said:


> I have another rookie question...
> 
> Can you only use a split bolt on an “in-line” connection or can you use it with both conductors entering the bolt from the same side?
> 
> ...


IMO, it's easier to tape up, and fit in the peckerhead, split bolt connections with the wires coming in side by side rather than from opposite sides. I may be wrong so try it out and see what you like better. 88 and 33 are way cheaper than blue smoke releases. Ymmv.


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## splatz (May 23, 2015)

SpaceMonkey said:


> I have another rookie question...
> 
> Can you only use a split bolt on an “in-line” connection or can you use it with both conductors entering the bolt from the same side?


I am always looking for an excuse to post the 3m taping videos. Not surprisingly they go pretty heavy on the tape LOL. 

The split bolt is pretty hard to beat, you can use it for a side by side splice, an inline splice, or a tap and run connection. 

With crimp on rings you lose a little wire every time you have to undo and redo the splice, with wire nuts or split rings you might not lose any wire.


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## SpaceMonkey (Sep 19, 2018)

What type of lock nut/washers do you guys like to use for bolted connections?


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## splatz (May 23, 2015)

SpaceMonkey said:


> What type of lock nut/washers do you guys like to use for bolted connections?


I don't think I have used them for this but the Bellville washers are pretty good, I see they are aka "Disc Springs" at McMaster Carr.


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## SpaceMonkey (Sep 19, 2018)

splatz said:


> I don't think I have used them for this but the Bellville washers are pretty good, I see they are aka "Disc Springs" at McMaster Carr.




What would be your next choice? I tried a couple places around me and nobody had them


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## splatz (May 23, 2015)

SpaceMonkey said:


> What would be your next choice? I tried a couple places around me and nobody had them


A regular split lock washer, which I am not sure does much at all, and cross my fingers.


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## JRaef (Mar 23, 2009)

SpaceMonkey said:


> What would be your next choice? I tried a couple places around me and nobody had them
> 
> 
> Sent from my iPhone using Tapatalk


The more common term that hardware people will know them by is "Belleville washers" or "Conical washers". They are convex (or concave depending on which side you look at) and made from spring steel so when tightened, they flatten out and their spring tension is always pushing against the bolt/screw threads, keeping them tight..










https://en.wikipedia.org/wiki/Belleville_washer


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## SpaceMonkey (Sep 19, 2018)

Thanks for all the help guys.

What material do you guys prefer for the nut and bolt? Stainless?


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## paulengr (Oct 8, 2017)

splatz said:


> A regular split lock washer, which I am not sure does much at all, and cross my fingers.


They promote looseness. Do not use helical spring washers aka split washers. Lock washers is NOT what they are. No such thing as a lock washer. Lock nuts but not lock washers.


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## paulengr (Oct 8, 2017)

SpaceMonkey said:


> Thanks for all the help guys.
> 
> What material do you guys prefer for the nut and bolt? Stainless?


Depends. Stainless helps in corrosion but grade 8s are cheap sold by the pound at tractor supply. If you get it tight enough the joint is gas tight anyways.


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## SpaceMonkey (Sep 19, 2018)

paulengr said:


> They promote looseness. Do not use helical spring washers aka split washers. Lock washers is NOT what they are. No such thing as a lock washer. Lock nuts but not lock washers.
> 
> 
> Sent from my SM-T350 using Tapatalk




Are you referring to the nuts with the piece of nylon? 


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## paulengr (Oct 8, 2017)

SpaceMonkey said:


> Are you referring to the nuts with the piece of nylon?
> 
> 
> Sent from my iPhone using Tapatalk


A washer that is split and basically a single turn spring is officially called a helical spring washer. The common misnomer is a 'lock washer'. It actually creates looseness. It is supposed to take up slack in the joint like the Belleville washers mentioned earlier but since it has only a tiny amount of tension in one spot it doesn't do that job well. But it actually makes things worse. See the following.

http://www.boltscience.com/pages/helicalspringwashers.htm

The nylon/nut thing is a nylock which is a lock nut. You can also get various lock nuts with a deformed thread in various designs that work well. Thread locker adhesive (loc tite) also works well. MbS also works (Never Seez) but it's not a locker. It's a thread lubricant that makes the torque more consistent when tightening, promoting better tightening. All of these have been tested in electrical joints and have no issues. The only one I'd be nervous about is the nylocks due to the very low softening temperature (about 130-135 C) for plastics. With no pressure on it it's one thing for insulation but quite another for a fastener under tension.

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## splatz (May 23, 2015)

paulengr said:


> Thread locker adhesive (loc tite) also works well. MbS also works (Never Seez) but it's not a locker. It's a thread lubricant that makes the torque more consistent when tightening, promoting better tightening. All of these have been tested in electrical joints and have no issues.


I did not know Loctite was approved for electrical connections. I have always had good luck with that in mechanical applications. I just figured if you're getting that on the mating surfaces you'd be creating a high resistance joint. 

I figured if it was allowed, T&B would be selling it for 20 times the price of regular Loctite


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## glen1971 (Oct 10, 2012)

paulengr said:


> They promote looseness. Do not use helical spring washers aka split washers. Lock washers is NOT what they are. No such thing as a lock washer. Lock nuts but not lock washers.
> 
> 
> Sent from my SM-T350 using Tapatalk


Guess I got a lot of rework to do on tons of motors.. Never had issues of them becoming loose.


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## Going_Commando (Oct 1, 2011)

I don't hate ring/bolt connections, though I have seen them loosen. I'm a split bolt guy. I have also seen a pile of burnt up polaris connectors, and though they are super convenient, I only use them for temporary connections now.


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## John Valdes (May 17, 2007)

glen1971 said:


> Guess I got a lot of rework to do on tons of motors.. Never had issues of them becoming loose.


Yea. Me too.
I was a bit surprised to see how far this thread went. I mean how many ways can you terminate a motor?
Especially a 30 HP I think was the OP's comment. That size motor most likely comes from the factory with ring lugs and 1/4" hole. 

Many motor manufactures are supplying ring terminals on new product. I have seen some guys cut them off. Why?
I prefer lugs and bolts over a split bolt any day of the week. Even compression lugs.
Its faster and IMO more reliable.

And whatever method you guys use, please make it up so the next guy can get it apart. 
You used to be able to get varnish cambric without a sticky side. If its still available use it or wrap the connection glue side up until the connection is covered then rotate the roll and use the sticky side.
Remember, it could be you taking this connection apart.

I was disappointed to hear the Polaris connectors were not holding up.


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## paulengr (Oct 8, 2017)

splatz said:


> I did not know Loctite was approved for electrical connections. I have always had good luck with that in mechanical applications. I just figured if you're getting that on the mating surfaces you'd be creating a high resistance joint.
> 
> I figured if it was allowed, T&B would be selling it for 20 times the price of regular Loctite


I'd have to look up the testing to find it again. In a nut/bolt connection it's all common hardware which does not need Listing. Basically all electrical connections where loc tite would be used work the same way. You apply pressure and crack the oxide layer on the metals then squeeze to the point where the metal smears and squishes at the joint. Electrical joints are effectively cold welds. Any liquids or pastes if they are actually in the joint such as electrical joint compound are pushed out of the way. The nuts and bolts are not intentional conductors...They are fasteners. So conductivity, coatings, etc., don't matter with them in the first place. It's more valuable to brush the conductor to try to clean some oxide off or do it chemically with electrical joint compound. Bus bar manufacturers specify doing that as well as using Belleville washers and thread lube.

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## paulengr (Oct 8, 2017)

glen1971 said:


> Guess I got a lot of rework to do on tons of motors.. Never had issues of them becoming loose.


Self loosening is rare. It's called the Jost effect. You can Google that. The conditions are only under severe vibration, not something I would ever expect in a peckerhead. Lock "washers" promote self loosening, if it happens. They don't "lock" anything or promote consistent joint tightness. "Lock" washers including the split ones, star ones, and serrated ones have been used for years on faith and belief that they prevent looseness. Actual testing has proven otherwise, so installation practices need to change. NASA and automotive plants eliminated these years ago in their specs.

The argument that it's been done that way for years is stupid. Soldering joints has been around since the days when we used the telegraph joint and coated the solid core wire in solder. It seemed like the right thing to do and was practiced for decades if not centuries. Automotive companies did research on it and found that soldered joints are weaker. Do you still solder joints knowing that it weakens the wire and promotes strand breakage?

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## paulengr (Oct 8, 2017)

John Valdes said:


> Yea. Me too.
> I was a bit surprised to see how far this thread went. I mean how many ways can you terminate a motor?
> Especially a 30 HP I think was the OP's comment. That size motor most likely comes from the factory with ring lugs and 1/4" hole.
> 
> ...


The big thing with varnished cambric is it doesn't stick. I just use vinyl tape upside down the same way.

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## bill39 (Sep 4, 2009)

paulengr said:


> The big thing with varnished cambric is it doesn't stick. I just use vinyl tape upside down the same way.
> 
> Sent from my SM-T350 using Tapatalk


There is varnished cambric that is sticky. Don’t know the number but have used it.


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## SpaceMonkey (Sep 19, 2018)

I have some 2520 varnished cambric. 2510 is the “no adhesive” one. The adhesive is pretty mild on the 2520, sticky side out seems to work fine 


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## Going_Commando (Oct 1, 2011)

I use the "sticky" varnished cambric and have had to cut my joints open. The cambric even with the weak adhesive is way easier to crack open than any other combo I've tried. Cambric, rubber, then 33 or 88 is a time proven combo that provides solid electrical and mechanical protection. 

Around here it is hard to get ring terminals larger than #10 with any regularity. None of the supply houses have consistant stock. I try to keep a variety in the t&b crimper case, but I ain't perfect, and the crimp tool lives in the shop. Split bolts are easier to stock since you have more overlap with wire range. I stock up to #10 rings in the truck, so I will either ring and bolt or use barrel crimps and wrap cap for smaller motors, and use split bolts for bigger ones for emergency calls. If I have time to plan ahead and have lead time I will order ring terminals to fit and grab the crimp tool.


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## John Valdes (May 17, 2007)

paulengr said:


> The big thing with varnished cambric is it doesn't stick. I just use vinyl tape upside down the same way.





SpaceMonkey said:


> I have some 2520 varnished cambric. 2510 is the “no adhesive” one. The adhesive is pretty mild on the 2520, sticky side out seems to work fine


Yes it comes both ways now. When I first started it came without a sticky side. 

I still have a partial roll of "friction" tape somewhere.
We always used that for the last layer for mechanical protection. I don't remember if friction tape had any dialectic properties or not.
But it went on last.
I think POCO's may still use friction tape?


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