Industrial motor wire connections

[Snapped-off]

What's out there for wiring up motors in industrial applications? I found polaris lugs and those seem like they might be the ticket, but wanted to get some opinions from the pros. Our motors are all 12 wire 14awg, and our phase wires are 12awg.

We currently use wire nuts but every few months it seems we end up with a short somewhere in a peckerhead when the connections fail.

Some guys wrap them up in tape, but they still fail cause I just fixed one like that last night. One guy just tried out a machine screw/nut a few weeks ago and balled it up in tape. Haven't had issues with it but seems excessive.

Failures are definitely from the nuts vibrating loose over time.

 

[PCustoms]

Ring terminals and a bolt.

We used to use Adhesive lined heat shrink over that, crimp then end of the shrink to itself while hot. Sealed against heavy vibration and oil.

 

[Snapped-off]

Ring terminals and a bolt.

We used to use Adhesive lined heat shrink over that, crimp then end of the shrink to itself while hot. Sealed against heavy vibration and oil.

We had a guy do that with another repair a few weeks ago, minus the shrink tube. Just seeing what else is out there.

 

[PCustoms]

We had a guy do that with another repair a few weeks ago, minus the shrink tube. Just seeing what else is out there.

It's been a few years, but that was the most reliable method we found in a high vibration, oil soaked environment.

Next option, which removed the need for electrical work, was a Meltric HP rated plug.

 

[mm08822]

It's been a few years, but that was the most reliable method we found in a high vibration, oil soaked environment.

Next option, which removed the need for electrical work, was a Metric HP rated plug.

Meltric?

How would a plug eliminate the internal connections?

 

[Firebrick43]

Uninsulated ring terminals w bolts, then cambic tape, two wraps of rubber splicing tape, and two wraps of electrical tape

Wire nuts on industrial motors and pumps has been against professional standards since 2007.

It’s all right here on the how and why

https://techtopind.net/files/download-item/pdf_documents/Lead_Connection_Recommedation_document.pdf

 

[PCustoms]

Meltric?

How would a plug eliminate the internal connections?

Yes, autocorrect.....

I don't recall how the plug connects, but it address the wire nut/bolt etc. Issue that the OP described and removed the need for an electrician at our facility.

 

[PCustoms]

Uninsulated ring terminals w bolts, then cambic tape, two wraps of rubber splicing tape, and two wraps of electrical tape

Wire nuts on industrial motors and pumps has been against professional standards since 2007.

It’s all right here on the how and why

https://techtopind.net/files/download-item/pdf_documents/Lead_Connection_Recommedation_document.pdf

This works too.

We had at least one guy on staff that couldn't follow instructions, this the heat shrink rule was implemented. Pretty hard to eff up and when I caught someone not following it was easy to document.

 

[TurnipTruck]

Uninsulated ring terminals w bolts, then cambic tape, two wraps of rubber splicing tape, and two wraps of electrical tape

Wire nuts on industrial motors and pumps has been against professional standards since 2007.

I can attest that this is all I ever saw in heavy industry peckerheads (<600v) until a decade ago when we got the heavywall goo-filled heat shrink.

 

[logixjock]

Uninsulated ring terminals w bolts, then cambic tape, two wraps of rubber splicing tape, and two wraps of electrical tape

Wire nuts on industrial motors and pumps has been against professional standards since 2007.

It’s all right here on the how and why

https://techtopind.net/files/download-item/pdf_documents/Lead_Connection_Recommedation_document.pdf

I was taught 2 wraps of friction, 2 wraps of rubber, and 3 wraps of vinyl many years ago. The peckerhead cover would barely fit back on most of the time. Glad I got into controls after that.

 

[Firebrick43]

I was taught 2 wraps of friction, 2 wraps of rubber, and 3 wraps of vinyl many years ago. The peckerhead cover would barely fit back on most of the time. Glad I got into controls after that.

If you were not neat with your job sometimes they would not fit! I had an apprentice several times tell me it wouldn’t and I would re wrap it and it would, but tight. The rubber tape is where most go wrong.

This works too.

We had at least one guy on staff that couldn't follow instructions, this the heat shrink rule was implemented. Pretty hard to eff up and when I caught someone not following it was easy to document.

The one thing I hated about glued heat shrink was removing it and not damaging the wires. If you laid the cambic and splicing tape sticky side out it was relatively easy to remove

 

[nadogail]

This works too.

We had at least one guy on staff that couldn't follow instructions, this the heat shrink rule was implemented. Pretty hard to eff up and when I caught someone not following it was easy to document.

Those who can’t or won’t follow instructions have no place in my crew.
If I gave them bad instructions, I am responsible. Failure to follow instructions can be reason for termination.

 

[nadogail]

I at the airport and relearning why I am generally quite content not traveling. At the very least everybody is minding their manners and the staff is both professional and respectful.

Much of the two legged scenery is attractive and the rest makes the attractive ones look better.

Posted in the wrong thread, my bad.

 

[Snapped-off]

Seems like ring terminals and fasteners are the industry standard. Probably switch over to that as failures happen.

I'd still like to try out a polaris or similar multi tap connector and see how they hold up.

 

[Firebrick43]

Seems like ring terminals and fasteners are the industry standard. Probably switch over to that as failures happen.

I'd still like to try out a polaris or similar multi tap connector and see how they hold up.

I think you will find Polaris connectors will be too large to fit in the pecker head.

We looked into them years ago for larger motors (instead is split bolts) and they were to large.

 

[Snapped-off]

I think you will find Polaris connectors will be too large to fit in the pecker head.

We looked into them years ago for larger motors (instead is split bolts) and they were to large.

What size motors? All our stuff is pretty small at 3hp - 15hp. Probably 100 motors give or take.

 

[Bert_]

I like split bolts as being the best honestly but I use a lot of wire nuts on small motors

 

[Firebrick43]

What size motors? All our stuff is pretty small at 3hp - 15hp. Probably 100 motors give or take.

The ones we tried were for 40 hp motors if I recall correctly.

I know they make smaller ones but the peckerhead is smaller as well.

 

[Firebrick43]

I like split bolts as being the best honestly but I use a lot of wire nuts on small motors

See the link on post 6

 

[Bert_]

See the link on post 6

The link only opens a blank page, nothing to read

A crimp on a ring terminal can fail too. I'm not going to suggest either is right or wrong, I use wire nuts almost exclusively for anything #10 or less and don't see many failures. I think a split bolt is the best connection but they are time consuming.

 

[Firebrick43]

A crimp on a ring terminal can fail too. I'm not going to suggest either is right or wrong, I use wire nuts almost exclusively for anything #10 or less. I think a split bolt is the best connection but they are time consuming.

It works on two different discrete devices I have. Since its a PDF your browser is probably saving it to downloads

I guess it’s a possibility although I haven’t seen it yet but have seen 8 or 9 wire nut failures on motors.

But as quoted by the document that sections of the NFPA 79 and NEC state “twist on wire connectors shall NOT be used”

The NFPA is telling you it’s wrong.

And maybe for the sake of your job/business/ property you should take heed lest it’s confiscated by the civil courts if the wire nut was to cause a fire and cause property damage or worse.

 

[PCustoms]

In the application I was responsible for a wire nut would have been rattled to peices in days, if not hours.

 

[dutchgray]

I have always just used the terminal block that comes in the motor from the factory, usually a set of studs connected to the windings and you connect using ring terminals and nuts. But I am in the UK.
I do not understand how American motor manufacturers get away with having bare winding ends being the acceptable standard.

 

[Firebrick43]

I have always just used the terminal block that comes in the motor from the factory, usually a set of studs connected to the windings and you connect using ring terminals and nuts. But I am in the UK.
I do not understand how American motor manufacturers get away with having bare winding ends being the acceptable standard.

A hell of a lot of American motors have terminal blocks and smaller motors up to say 7.5hp.

To be honest the places I worked didn't have a lot of tweener motors, its was mostly 3 or 5 hp motors for coolant pumps on each machine or skipping to big 40hp pumps, 100 hp spindle motors, even a few 200 hp motors running high pressure (10k psi) washing machines.

While there may be one out there, I have never seen a german motor with terminal blocks. And most of the equipment I have worked on has been german.

You get into the big stuff there is no terminal blocks on any that I have seen.

 

[Snapped-off]

I have always just used the terminal block that comes in the motor from the factory, usually a set of studs connected to the windings and you connect using ring terminals and nuts. But I am in the UK.
I do not understand how American motor manufacturers get away with having bare winding ends being the acceptable standard.

We use Toshiba motors. Just bare wire ends. Sometimes they're already twisted together for high voltage, but still just bare ends.

We don't get a lot of failures, but with all the motors we have it does happen occasionally.

 

[Snapped-off]

So I'm going to look into ordering 6 connectors, either polaris or burndy to try out on a motor and see how long they last, and also some dedicated non insulated ring terminals with the tapes. I know we don't have cambric, but we've got rubber and vinyl.

 

[sparky 1971]

For motors that have #14, 12, 10, or 8, I use wire nuts. #6 and larger, the split bolts are coming out.

You gotta use good wire nuts. I am partial to Ideal. Orange 73B wire nuts, orange twisters, orange/blue twisters, tan twisters, red wing nuts, gray twisters, and blue wing nuts are all stocked on my truck.

 

[Firebrick43]

So I'm going to look into ordering 6 connectors, either polaris or burndy to try out on a motor and see how long they last, and also some dedicated non insulated ring terminals with the tapes. I know we don't have cambric, but we've got rubber and vinyl.

take pics of the smaller motors with the Polaris connectors, I am curious.

 

[cybrdyke]

3M Motor Lead Boots are awesome!
CD

 

[Snapped-off]

3M Motor Lead Boots are awesome!
CD

Looks like they still need to be fastened together with ring terminals.

 

[rkevins]

we would bolt connections the use these boots from Thomas Betts

 

[Snapped-off]

we would bolt connections the use these boots from Thomas Betts

How big are those? Got a link?

 

[cybrdyke]

Looks like they still need to be fastened together with ring terminals.

Yes. Makes it much easier to get to the connection, which doesn't have to be wrapped in tape or gooped up or anything.
CD

 

[Zrsnopro97]

How big are those? Got a link?

Those look pretty slick, have you checked grainger and/or mcmaster carr for them?

 

[Snapped-off]

Those look pretty slick, have you checked grainger and/or mcmaster carr for them?

No I found the multi-tap connectors in both Polaris and Burndy on Grainger. They're pricey though! I didn't look for the other stuff yet. I'll do that today

I'll show you the rest of the stuff I've been looking at and you can check it out tomorrow. That cambric tape is pricey as hell too.

I can see why we've been using wire nuts...

 

[mm08822]

It works on two different discrete devices I have. Since its a PDF your browser is probably saving it to downloads

I guess it’s a possibility although I haven’t seen it yet but have seen 8 or 9 wire nut failures on motors.

But as quoted by the document that sections of the NFPA 79 and NEC state “twist on wire connectors shall NOT be used”

The NFPA is telling you it’s wrong.

And maybe for the sake of your job/business/ property you should take heed lest it’s confiscated by the civil courts if the wire nut was to cause a fire and cause property damage or worse.

NFPA 79 is a guidence doc only. I doubt it has been legally adopted, anywhere.
Where in NFPA 70 (NEC) does it prohibit?

 

[Firebrick43]

NFPA 79 is a guidence doc only. I doubt it has been legally adopted, anywhere.
Where in NFPA 70 (NEC) does it prohibit?

First, NEC 70 (AKA NFPA 70) is the professional standards for wiring of the building/structure/ect that supplies equipment or "outside" the equipment. It is NOT how the equipment "inside" is wired. The standards in NFPA 70 have been adopted AS code in all 50 states.

Second, its more that a "guidance document". Its a set of professional standards that machine builders use, and yes, from the above sentence it is not the NEC which is why I didn't say code but "professional standards" in post 6.

All industrial machinery sold in the USA is going to be built to NFPA 79 standards.

As quoted from the NFPA

"In the US, Authorities Having Jurisdiction (AHJs), will use NPFA 79 as part of their enforcement activities to check equipment on-site – but this is often refined further by local interpretation of the standard and the application of additional local laws on-site, such as the NFPA 70 National Electrical Code, NFPA 70E Standard for Electrical Safety in the Workplace and CFR 1910 – Federal Law"

OSHA will fine after accidents if equipment is not built or maintained according to professional standards.
OSHA does not quote from the NEC 70 when giving fines, it quotes from NFPA 70, the "professional standard"

The NEC Sec. 110.3(B)
"Installation and Use. Listed or labeled equipment shall be
installed and used in accordance with any instructions included
in the listing or labeling."

In plain terms, follow the instructions and standards the manufacture built to, which again, all industrial equipment is built to NFPA 79

One unique item that NEC does cover because they are not always inside or directly part of a machine is pumps. As already cited in post 6.

"NEC 70HB-2014 695.6 Power Wiring (D) Pump Wiring. All wiring from the controllers to the pump motors shall be in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, liquidtight flexible metal conduit, or liquidtight flexible nonmetallic conduit Type LFNC-B, listed Type MC cable with an impervious covering, or Type MI cable. Electrical connections at motor terminal boxes shall be made with a listed means of connection. Twist-on, insulation-piercing–type, and soldered wire connectors shall not be permitted to be used for this purpose"

Then lastly, civil tort. If some one is injured, killed, or property damaged and they find the cause to be wirenuts hooking up a motor, it is very unlikely even a good lawyer can convince a judge or jury that its not their fault when they ignored "professional standards" If death occurs even criminal negligence is possible.

 

[rkevins]

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we bought them from the wholesale house we got all our supplies from.
There are at least 2 sizes I have used. We would wire nut and tape if the supply wire was 8, 10, or 12 after that up to 500mcm was lugged and bolted it sped up production and stopped accidental arcing from not being taped correctly after we started using the boots and the time saved made up more than the cost difference

 

[sparky 1971]

It's been about a month ago, but I replaced a small three phase motor for an exhaust fan. It came already wired from for 480 and 4-7, 5-8, and 6-9 were factory connected with wire nuts. I remember it well because I needed to make it 208 and I couldn't get the stupid wire nuts off. I had to cut them in order to make the switch.

 

[mm08822]

First, NEC 70 (AKA NFPA 70) is the professional standards for wiring of the building/structure/ect that supplies equipment or "outside" the equipment. It is NOT how the equipment "inside" is wired. The standards in NFPA 70 have been adopted AS code in all 50 states.

There are still small pockets where that is not the case. Adopted means legislated into effect and enforcable for each state/locale.

Second, its more that a "guidance document". Its a set of professional standards that machine builders use, and yes, from the above sentence it is not the NEC which is why I didn't say code but "professional standards" in post 6.

Guidance document meaning non-enforcable. It also means optional to comply with any or all of it. No one is questioning the years of best practices compiled into NFPA 79.

All industrial machinery sold in the USA is going to be built to NFPA 79 standards.

As quoted from the NFPA

"In the US, Authorities Having Jurisdiction (AHJs), will use NPFA 79 as part of their enforcement activities to check equipment on-site – but this is often refined further by local interpretation of the standard and the application of additional local laws on-site, such as the NFPA 70 National Electrical Code, NFPA 70E Standard for Electrical Safety in the Workplace and CFR 1910 – Federal Law"

All machinery sold in the US in not built to NFPA 79. EN 60204-1 is also a standard for purchased equipment and easilly approved by FM and other Insurance Co's. Yes equipment from the EU is sold in the US.
That statement above in red is part of an NFPA infomercial. It starts with "thou shall" and quickly back-pedals.
Until it is legislated into effect, it holds no more legal weight than a comic book. Customers of equipment purchased may spec to NFPA 79 but that is a business - business transaction requirement.

OSHA will fine after accidents if equipment is not built or maintained according to professional standards.
OSHA does not quote from the NEC 70 when giving fines, it quotes from NFPA 70, the "professional standard"

What? NFPA 70 is the NEC.

The NEC Sec. 110.3(B)
"Installation and Use. Listed or labeled equipment shall be
installed and used in accordance with any instructions included
in the listing or labeling."

And every motor sold strictly prohibits the use of wirenuts? Really? Probably most are silent on that detail.

In plain terms, follow the instructions and standards the manufacture built to, which again, all industrial equipment is built to NFPA 79

One unique item that NEC does cover because they are not always inside or directly part of a machine is pumps. As already cited in post 6.

"NEC 70HB-2014 695.6 Power Wiring (D) Pump Wiring. All wiring from the controllers to the pump motors shall be in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, liquidtight flexible metal conduit, or liquidtight flexible nonmetallic conduit Type LFNC-B, listed Type MC cable with an impervious covering, or Type MI cable. Electrical connections at motor terminal boxes shall be made with a listed means of connection. Twist-on, insulation-piercing–type, and soldered wire connectors shall not be permitted to be used for this purpose"

You have selected fire pumps to make your point. Fire pumps are considered expendable when life safety and building destruction is present. The mindset is to run it until it dies or burns up with the rest of the building. A very different situation than the other 99.9% of motors installed with overload protection settings to shut down the motor and protect it.

Then lastly, civil tort. If some one is injured, killed, or property damaged and they find the cause to be wirenuts hooking up a motor, it is very unlikely even a good lawyer can convince a judge or jury that its not their fault when they ignored "professional standards" If death occurs even criminal negligence is possible.

So you say. If the equipment was installed meeting enforcable codes in effect at the time, then the requirements were met.