# Hard Pipe for Motor



## kdoyle2011 (Feb 8, 2013)

Where in the code book does it say you can't hard pipe to a motor.


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## Pete m. (Nov 19, 2011)

kdoyle2011 said:


> Where in the code book does it say you can't hard pipe to a motor.


It doesn't.

Pete


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## Dennis Alwon (May 9, 2009)

I am not certain the NEC states this however the motor installation may require flexibility in which case it may not be hard wired.


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## oldtimer (Jun 10, 2010)

Dennis ! On post #3 I realize that when you say hard wired , you mean hard Piped .

Just thought I would bring this to your attention before someone jumps on it !


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## Dennis Alwon (May 9, 2009)

oldtimer said:


> Dennis ! On post #3 I realize that when you say hard wired , you mean hard Piped .
> 
> Just thought I would bring this to your attention before someone jumps on it !


TY-- yes I meant hard piped...:thumbsup:


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## KennyW (Aug 31, 2013)

I don't think it does, but the other side of the coin is, just because the code does not expressly prohibit something, doesn't automatically make it good practice. 

The majority of industrial sites I work at would prohibit such a practice and I would think twice about what the perceived benefit would be. 

The other hint is 430.223 "Raceway Connection to Motors". They make a point of allowing a flexible connection from a raceway to a motor. Yes they just allow it, not require it. 

At any rate, even if the motor is rigidly mounted I'd consider at least just using MC. Makes it much easier to replace, and all motors vibrate a little.


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## Pete m. (Nov 19, 2011)

KennyW said:


> I don't think it does, but the other side of the coin is, just because the code does not expressly prohibit something, doesn't automatically make it good practice.
> 
> The majority of industrial sites I work at would prohibit such a practice and I would think twice about what the perceived benefit would be.
> 
> ...


I agree with what you say. 

Pete


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## Big John (May 23, 2010)

I think the value of flex is often really overrated, and we use it mostly because that's the way it's always been done.


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## don_resqcapt19 (Jul 18, 2010)

Big John said:


> I think the value of flex is often really overrated, and we use it mostly because that's the way it's always been done.


I think we really use it because it is much quicker and easier than trying to hard pipe the motor.


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## Big John (May 23, 2010)

don_resqcapt19 said:


> I think we really use it because it is much quicker and easier than trying to hard pipe the motor.


 I don't find anything faster or easier about installing a flexible whip on a pipe run as opposed to landing that same pipe directly at the device. Takes extra labor to make up the whip, and often extra time to get the conductors through it.


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## Jlarson (Jun 28, 2009)

We have a few places with motors that are piped with RMC. Real pain when you go to replace one because the pipe is always in just the right spot that it's in the way of lifting/shoving/prying the new motor in place.


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## KennyW (Aug 31, 2013)

Big John said:


> I think the value of flex is often really overrated, and we use it mostly because that's the way it's always been done.


If it's really that tough to pull te cables through 6 feet of sealtite and put 2 connectors on, then I'd consider that the value of MC cable in such a situation is really underrated, and makes the whole question a non-issue.

Besides the fact that, like JLarson said, if we went into an industrial site and hard-piped right to motors the maintenance department would be chasing us with torches and pitchforks.


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## ponyboy (Nov 18, 2012)

Big John said:


> I think the value of flex is often really overrated, and we use it mostly because that's the way it's always been done.


Agreed. That being said, even I've never hard piped a motor. Yet


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## sparkywannabee (Jan 29, 2013)

Running pipe to a motor is the most chicken**** thing i have ever heard of, we have hundreds of motors in our plant, some on equipment that was put together before it came in, anything that does not have cord or SO is LFMC, period, no rigid, EMT, flex, mc, etc. Anybody likes pipe that much is a wanna be plumber or needs to come out of the closet.


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## Big John (May 23, 2010)

:thumbup: Awesome. Try visiting some other plants sometime. Lots of hard pipe out there.


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## millelec (Nov 20, 2010)

prefer flex. remove and re-install motor/pump combos for overhaul/repair. things are aggravating enough without hardpipe. initial installation might be easier in pipe, but flex works better on a repeat basis. (just mho :jester


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## 360max (Jun 10, 2011)

Big John said:


> I think the value of flex is often really overrated, and we use it mostly because that's the way it's always been done.


I have always used flex, but either way, your looking at at _locknut_ holding it together


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## Wirenuting (Sep 12, 2010)

The only time I've ever hard piped a large motor is when the whole unit is sitting on an anti-shock base. Even then you flex into the unit..


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## don_resqcapt19 (Jul 18, 2010)

Big John said:


> I don't find anything faster or easier about installing a flexible whip on a pipe run as opposed to landing that same pipe directly at the device. Takes extra labor to make up the whip, and often extra time to get the conductors through it.


In my area they want the motor terminal box opening on the bottom side of the terminal box. Hard pipe would almost always require an additional conduit fitting or two, and an union (most all of the motor terminal boxes that I see have a threaded opening). Conduit labor is always greater than flex labor. The conduit fittings and union will cost more than the LFMC and two connectors.

Our installations almost always have the control conductors for the HOA in the same raceway as the motor conductors and the wire will be pulled to the Tee fitting where the wiring will be split between the motor and the HOA, and not directly to the motor, so no additional wire pulling labor.


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## Big John (May 23, 2010)

360max said:


> I have always used flex, but either way, your looking at at _locknut_ holding it together


 13,000 horsepower, 4" rigid:










I agree with y'all that flex can definitely make changing a motor easier, but I've also swapped a lot of hard pipe with little trouble. I see a ton of hard pipe on large frame motors where a couple feet of flex wouldn't make a bit of difference in the overall difficulty of removing it.

I guess my point is to actually think about the install instead of doing it "just because": If hard pipe isn't gonna screw future maintenance and it makes my job easier, you bet I hard pipe. But if maintenance or vibration/sound calls for flex, so be it.


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## ponyboy (Nov 18, 2012)

sparkywannabee said:


> Running pipe to a motor is the most chicken**** thing i have ever heard of, we have hundreds of motors in our plant, some on equipment that was put together before it came in, anything that does not have cord or SO is LFMC, period, no rigid, EMT, flex, mc, etc. Anybody likes pipe that much is a wanna be plumber or needs to come out of the closet.


I'm gonna hard pipe a 2 hp motor this week sometime and take a picture. Just for you. I hardpiped this 1.5 MW generator last year. How does this make you feel?


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## sparkywannabee (Jan 29, 2013)

Running pipe to a generator or compressor or other equipment, which we all do, is not the same thing as running pipe to a motor Einstein. The vibration is going to cause the insulation to rub through and short or ground, eventually. It should be against code, and i think i am going to make a suggestion to the powers that be, so you better hurry up with that 2 HP and get grandfathered in.


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## ponyboy (Nov 18, 2012)

sparkywannabee said:


> Running pipe to a generator or compressor or other equipment, which we all do, is not the same thing as running pipe to a motor Einstein. The vibration is going to cause the insulation to rub through and short or ground, eventually. It should be against code, and i think i am going to make a suggestion to the powers that be, so you better hurry up with that 2 HP and get grandfathered in.


Lol. What's your stance on piping into transformers?


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## sparkywannabee (Jan 29, 2013)

Big John said:


> :thumbup: Awesome. Try visiting some other plants sometime. Lots of hard pipe out there.


I would, but they don't let me in the door, they are worried i'll start ripping out all the piped motors and putting in liquidtight.


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## sparkywannabee (Jan 29, 2013)

ponyboy said:


> Lol. What's your stance on piping into transformers?


Once again, i thought we were talking motors. Transformers can be hard piped but flex or lfmc is preferrable.


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## ponyboy (Nov 18, 2012)

sparkywannabee said:


> Once again, i thought we were talking motors. Transformers can be hard piped but flex or lfmc is preferrable.


What about air conditioners?


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## ponyboy (Nov 18, 2012)

ponyboy said:


> What about air conditioners?


I hardpiped a hi bay fixture once


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## sparkywannabee (Jan 29, 2013)

ponyboy said:


> What about air conditioners?


depends, do you mean like the heating/cooling Carrier units. If its rooftop, probably LFMC, pad mount, probably pipe. If you ever peek inside one of those units you wont find any comp or fan motors hardpiped either.


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## sparkywannabee (Jan 29, 2013)

ponyboy said:


> I hardpiped a hi bay fixture once


once again, not a motor.


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## Next72969 (Dec 9, 2012)

sparkywannabee said:


> Running pipe to a motor is the most chicken**** thing i have ever heard of, we have hundreds of motors in our plant, some on equipment that was put together before it came in, anything that does not have cord or SO is LFMC, period, no rigid, EMT, flex, mc, etc. Anybody likes pipe that much is a wanna be plumber or needs to come out of the closet.


 oookkkkayyy


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## ponyboy (Nov 18, 2012)

sparkywannabee said:


> once again, not a motor.


What about like a laser or a big cnc. There's like 100 motors in them right?


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## ponyboy (Nov 18, 2012)

Servos?


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## Big John (May 23, 2010)

sparkywannabee said:


> ...The vibration is going to cause the insulation to rub through and short or ground, eventually. It should be against code....


 The one in the picture I posted vibrates so much that you could feel in the soles of your feet while standing outside in the parking lot. It's been running fine for 30 years. It's really rare I see anything that vibrates so much it _needs _flex.


ponyboy said:


> I hardpiped a hi bay fixture once


 Why do you hate your customers?


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## ponyboy (Nov 18, 2012)

Big John said:


> Why do you hate your customers?


You can't take me so serious Johnny


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## sparkywannabee (Jan 29, 2013)

I am not trying to ruffle any feathers, step on any toes here guys, its just that in my limited experience, wires running in pipe in high vibration areas don't do as well as liquidtight, almost like its flexibility is a shock absorber. Just last month, on this big oven we have, the wires in the pipe to the hi-temp limit were rubbed thru and tripping the contrl power breaker to the whole panel. I cannot recall ever seeing wires rubbed thru in LFMC, although i am sure it happens. That big motor John worked on has a lot of pipe, probably with a bunch of 750 in it, maybe that holds up better than 12 thhn in 1/2" pipe, or maybe its time is coming,i am sure they megger the conducters pretty often. BTW, funny thing about hi bays, in our old building, 120,000sq ft., all of the damn things are hardpiped.


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## don_resqcapt19 (Jul 18, 2010)

Big John said:


> ...
> I agree with y'all that flex can definitely make changing a motor easier, but I've also swapped a lot of hard pipe with little trouble. I see a ton of hard pipe on large frame motors where a couple feet of flex wouldn't make a bit of difference in the overall difficulty of removing it. ...


Yes a couple of feed of large diameter LFMC is really not that flexible.


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## don_resqcapt19 (Jul 18, 2010)

ponyboy said:


> I hardpiped a hi bay fixture once


I have seen 2x4 lay-ins hard piped (EMT)...won't be fun to replace the fixtures when the time comes.


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## Big John (May 23, 2010)

ponyboy said:


> You can't take me so serious Johnny


 Me either. :whistling2:


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## ponyboy (Nov 18, 2012)

Big John said:


> Me either. :whistling2:


Touché


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## RICHGONZO1 (Mar 5, 2012)

Either way, hard piping to a standard lower HP induction motor up to couple hundred HP is just not convenient for the maintenance required because everything fails eventually. The big dogs, hopefully some preventative maintenance was done on it such as PDMA, should be changed out during a scheduled outage where time really isn't holding up production. In the real world, production rules and the faster you change that motor, the more money your company or whoever writes your check makes. We have all seen services fail in hard pipe and flex or god forbid tech 90 cable, I believe in the KISS method, keep it simple stupid!


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## varmit (Apr 19, 2009)

Way back when, most industrial locations used RMC directly into the motor peckerhead. I have been in pump rooms with 50 plus motors- all hard piped. 
The next evolution was that no flex could be longer than 18 inches. Now most folks just rope out cable.

One thing that made hard piping of motors practical back then was that almost all motors, down to the smallest were rebuilt and identical spares were stocked. Now days, the price break on rebuild/replace of a motor is usually about a 25 HP motor.


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> Yes a couple of feed of large diameter LFMC is really not that flexible.


Well sure it does on large diameter flex .


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## piperunner (Aug 22, 2009)

ponyboy said:


> Lol. What's your stance on piping into transformers?


 Well you flex them they vibrate .:thumbsup:


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## piperunner (Aug 22, 2009)

ponyboy said:


> I'm gonna hard pipe a 2 hp motor this week sometime and take a picture. Just for you. I hardpiped this 1.5 MW generator last year. How does this make you feel?
> 
> 
> View attachment 34701
> ...


 
Well we done a few 45 MW generators in vero and we use flex duct to attach 
they were GE . 
:thumbup:


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## ponyboy (Nov 18, 2012)

piperunner said:


> Well we done a few 45 MW generators in vero and we use flex duct to attach they were GE . :thumbup:


Well you are the best after all


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> I have seen 2x4 lay-ins hard piped (EMT)...won't be fun to replace the fixtures when the time comes.


Well hope the fixture was UL stamped inside with the words pass thur fixture 
or that's not NEC code . Plus they must be idiots to do that anyway its cheaper to jumper in with a whip in like normal electricians not to replace but theres some rules in some states that the fire marshal would like them to fall down one at a time then the whole ceiling at once .
When you putting out a fire and the ceiling falls . 
The code book is just a book but doesn't apply to every job or state some folks do quality work for the future some just hack it per the code .:thumbup:


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## piperunner (Aug 22, 2009)

ponyboy said:


> Well you are the best after all


 Well keep that to yourself pony don't let BBQ hear that .:laughing:


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> Well hope the fixture was UL stamped inside with the words pass thur fixture
> or that's not NEC code .
> Plus they must be idiots to do that anyway its cheaper to jumper in with a whip in like normal electricians not to replace but theres some rules in some states that the fire marshal would like them to fall down one at a time then the whole ceiling at once .
> When you putting out a fire and the ceiling falls .
> The code book is just a book but doesn't apply to every job or state some folks do quality work for the future some just hack it per the code .:thumbup:


First the branch circuit wiring did not enter the fixture as they set boxes on top of each fixture and pulled the ballast wires up into the box. Second, there is no listing required if you are only passing the lighting circuit, two wire or multiwire, itself through the fixture along with one additional two wire lighting branch circuit. 

The code book does apply to all jobs, but the code book is only a minimum standard. The minimum standard is only for the safety of the installation and not for quality work.


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> First the branch circuit wiring did not enter the fixture as they set boxes on top of each fixture and pulled the ballast wires up into the box. Second, there is no listing required if you are only passing the lighting circuit, two wire or multiwire, itself through the fixture along with one additional two wire lighting branch circuit.
> 
> The code book does apply to all jobs, but the code book is only a minimum standard. The minimum standard is only for the safety of the installation and not for quality work.


Well that's something I cant agree with the code book( dosent apply) to all jobs . Plus you need to explain your self better when you type a post .
Never seen anyone pull the ballast wires out of a 2x4 to the box that's hack .
I look at it this way your on the operating table having a quad by pass and you hear the doctor say to the intern hey just do a couple of minimum cross stitches the insurance doesn't pay for that extra stuff . LOL :thumbup:


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> ...
> I look at it this way your on the operating table having a quad by pass and you hear the doctor say to the intern hey just do a couple of minimum cross stitches the insurance doesn't pay for that extra stuff . LOL :thumbup:


Actually that is done every day...the quality of case is very much based on how much money you or your insurance company will pay.


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## sparkywannabee (Jan 29, 2013)

hey pony, that generator you installed, i wuz wondering about that pipe you ran, did the customer not want to pay to bury it, if so would'nt it have been better to elbow up and run it overhead. Reason i say that is, where i work at 20 jackasses would make that the new smoking area, sitting, standing on those pipes, hiding out behind the genny. Good quality work, though.


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> Actually that is done every day...the quality of case is very much based on how much money you or your insurance company will pay.[/quote
> 
> What you agree with what I said about bypass surgery wowa brother your
> into the code to much . You need to take a day off from all the forms your on .:no: Its just common sense to use flex on any motor or transformer doesn't have to say it in the code book . That's my point


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## 360max (Jun 10, 2011)

piperunner said:


> don_resqcapt19 said:
> 
> 
> > Actually that is done every day...the quality of case is very much based on how much money you or your insurance company will pay.[/quote
> ...


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## ponyboy (Nov 18, 2012)

Where are all these "vibrating" transformers? I probably install at least a transformer a week going on 3 years since I took this gig, with sizes ranging from 30 to 500 kva. I have never witnessed a transformer vibrate so much that it would loosen a wrench tight steel locknut. It's just not happening.


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## ponyboy (Nov 18, 2012)

sparkywannabee said:


> hey pony, that generator you installed, i wuz wondering about that pipe you ran, did the customer not want to pay to bury it, if so would'nt it have been better to elbow up and run it overhead. Reason i say that is, where i work at 20 jackasses would make that the new smoking area, sitting, standing on those pipes, hiding out behind the genny. Good quality work, though.


The inside floor is raised 4' above parking lot grade. Digging up the parking lot and burying it would've been more than what I did, it also would've been more work to go high. If guys wanna hang out and eat their lunch by the gen I couldn't care less. It's 4" grc and they couldn't hurt it if they tried


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## MHElectric (Oct 14, 2011)

ponyboy said:


> Well you are the best after all


:laughing:

I used to work with a guy just like him. He would curl his lips if he stepped foot on a MC job, he would talk all kinds of nonsense about these great & mysterious RMC jobs he had done in the past, he would think his way was THE ONLY WAY, he would interrupt everything anyone would say to him with his opinion, and he would start everything he said with "Well,..." :laughing: 

I get a goofy laugh every time I read his posts.


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> don_resqcapt19 said:
> 
> 
> > Actually that is done every day...the quality of case is very much based on how much money you or your insurance company will pay.[/quote
> ...


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## piperunner (Aug 22, 2009)

360max said:


> piperunner said:
> 
> 
> > ...if it was that much common sense it would be code, not all installs need or warrant flexable connections , whether vibration is there or not. It is still a locknut holding things together.
> ...


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> 360max said:
> 
> 
> > ...
> ...


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> piperunner said:
> 
> 
> > It would be a rare case where the hard pipe would be cheaper than flex...no matter how good you are with conduit, you can't bend, cut, thread and install conduit as quick as you can install flex.
> ...


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## MTW (Aug 28, 2013)

Piperunner, have you ever been in the GE plant in Schenectady, NY? Probably not. There are literally hundreds of transformers in there, all connected with RMC. Next time I'm there, I'll let them know they all need to be connected with flex. :laughing::no:


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## MTW (Aug 28, 2013)

ponyboy said:


> Where are all these "vibrating" transformers? I probably install at least a transformer a week going on 3 years since I took this gig, with sizes ranging from 30 to 500 kva. I have never witnessed a transformer vibrate so much that it would loosen a wrench tight steel locknut. It's just not happening.


Piperunner knows more than every electrician and code making panel in existence. You are to respect his authority, got it?


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## MTW (Aug 28, 2013)

piperunner said:


> Don please don't tell me about conduit or what we cant do with it we don't work in a office ive been in the field my whole time please .


And yet you still don't know anything. :laughing:

I connected an machine control cabinet to a 75 Kva transformer with Hoffman gasketed wireway last week. Hard connection with bolts all the way. I guess this won't meet your approval. :laughing:


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> don_resqcapt19 said:
> 
> 
> > Well listen Don you basically don't have a clue to what you talking about how pipe is easy to install and cheaper flex is a bitch to install . We install 4 inch seal tight and greenfield all the time the time in labor is way more then just installing a stick of EMT . Give it up your not going to sway my opinion on flex its been done that way for years on projects. I can not help it if you or anyone on this site hard pipes into a transformer or a motor there doing what the code book says but show me were in the code it tells you to install EMT into a motor or show me were it directly says run EMT into a transformer ?
> ...


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> piperunner said:
> 
> 
> > First I don't install EMT and I don't work in an office and have been doing this for 40 years.
> ...


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## MTW (Aug 28, 2013)

Etch this in stone. Piperunner has declared it, therefore it is so.


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## Fibes (Feb 18, 2010)

piperunner said:


> Plus you need to explain your self better when you type a post .


Well, considering the source that's got to be the funniest line ever submitted on ET. :thumbup:

BTW, it would help if everybody replying to piper started their posts with "Well"


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> don_resqcapt19 said:
> 
> 
> > Well for your company it might be more expensive running rigid or EMT its faster and cheaper for us . We don't buy 90 s we bend it never buy any elbows ever .
> ...


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## buddhakii (Jan 13, 2011)

I hard piped a little 5kva xfmr one time. It's the last time I will do it unless I see a spec for it. Engineer made me change it to flex. Not sure about other areas but it's pretty much industry standard here to flex into motors and xfmrs. 

Don, are you guys limited to bottom entry on all your enclosures as well? I'm seeing that spec a lot more. It can make things a real pia sometimes.


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## don_resqcapt19 (Jul 18, 2010)

buddhakii said:


> ...
> Don, are you guys limited to bottom entry on all your enclosures as well? I'm seeing that spec a lot more. It can make things a real pia sometimes.


Yes, unless the design of the equipment makes that physically impossible. 
The issue is water getting into the equipment. All conduit systems in wet locations leak and entering via the bottom helps prevent the water from getting into the equipment...of course the conduit has to be arranged to drain per 225.22.


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## MTW (Aug 28, 2013)

Typical Piperunner conversation: Piperunner declares something to be hack and wrong because he decided it is. Numerous electricians with decades of experience and code knowledge reply and tell him that he's the one who is wrong. Piperunner replies by digging in his heels and continuing to be contrary. Priceless. :laughing:


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## Big John (May 23, 2010)

ponyboy said:


> Where are all these "vibrating" transformers? I probably install at least a transformer a week going on 3 years since I took this gig, with sizes ranging from 30 to 500 kva. I have never witnessed a transformer vibrate so much that it would loosen a wrench tight steel locknut. It's just not happening.


 It's totally possible. If you don't use flex, the transformer can vibrate so much that if not secured it will actually start to walk. Worst case scenario it ended up out the door and down the street. Went to Taco Bell. Ordered a burrito supreme and a cherry Coke then it paid with pennies. True story. So you always use flex on transformers.


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## MTW (Aug 28, 2013)

Someone should do an experiment where they try to find the exact frequency of vibration where a locknut will actually begin to loosen. I guarantee it's not 60 hertz. :no::laughing:


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## piperunner (Aug 22, 2009)

Well I really enjoy MTW comments and a few others.
Times have changed on large projects today sound vibration its important my friends . Sound its air borne but vibration is ground borne its going to cause problems and the owners today and the engineers today don't read a code book . They are changing if the code cant keep up with high tech stuff besides its not life safety so they may not ever . It might never change but my work electrical is different then your work MTW . 

Theres new rules that the NEC is not up to date on. Companys are looking to eliminate problems that the NEC code book is not .

If your working in new York city ask anyone who works for CON ED whats new like the citys new noise ordinance of sound and what ABB has done to eliminate transformer vibrations for CON ED . 

Engineers on new projects in the last 10 years spec this you don't see it because you don't do the jobs we do . Sorry but your still in the stone age MTW .

We purchase and not just our company theres plenty of contactors from 30 kva to 65 mega watt transformers yes HV mega watt transformers that are 
designed for silent operation just about every new job we do were installing more and more special cut laminated cores or spring vibration .
Big jobs I hear are using low flux density cores this is whats new I cant help if the NEC is not up to date with what engineers want and the products on the market that folks with money need or want . Get educated heres what you need to read go to ABB look at what they build today .

New York City Con ED is getting new transformers just like other citys today 
we see it because we only do new work . You going to see new transformers in the near future and you already have seen LEDs take off . So keep up your smart remarks or uneducated talk about what or how things are done you have no clue .


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## Pete m. (Nov 19, 2011)

piperunner said:


> Well I really enjoy MTW comments and a few others.
> Times have changed on large projects today sound vibration its important my friends . Sound its air borne but vibration is ground borne its going to cause problems and the owners today and the engineers today don't read a code book . They are changing if the code cant keep up with high tech stuff besides its not life safety so they may not ever . It might never change but my work electrical is different then your work MTW .
> 
> Theres new rules that the NEC is not up to date on. Companys are looking to eliminate problems that the NEC code book is not .
> ...


Sound transmission and/or annoyance is not a safety concern. Therefore you wont find those requirements in the NEC. The job spec's can and often do exceed the requiremtns of the NEC.

Take a spin through 90.1. It will outline the purpose of the NEC. What you are describing may be "best practices" based upon an engineering study or two but it has nothing to do with the NEC.

Pete


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## MTW (Aug 28, 2013)

piperunner said:


> you have no clue .


Well you are just the greatest electrician who has ever lived.


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## piperunner (Aug 22, 2009)

Pete m. said:


> Sound transmission and/or annoyance is not a safety concern. Therefore you wont find those requirements in the NEC. The job spec's can and often do exceed the requiremtns of the NEC.
> 
> Take a spin through 90.1. It will outline the purpose of the NEC. What you are describing may be "best practices" based upon an engineering study or two but it has nothing to do with the NEC.
> 
> Pete


 Well yes it is the best practice that's why we use flex and don't hard pipe 
that's my point .

What your missing in my post is you follow NEC rule at work .We use it to pass inspection but go beyond it most of the time .
I don't need to spin through 90 .1 been there done that I know what the NEC is trust me. 
yes its not life safety so its not needed by the NEC . But if you have a core that vibrates at fundamental 1st 3rd 5th 7th odd HF you have a electrical problem and if you think vibration is not a issue your very wrong .
I like the comments it moved across the floor or it wont loosen up a locknut.
It will over time loosen up lugs wire & locknuts bad couplings in you pipe run.
Vibrating metal at a freq you cant physically see with your eyes .Ill bet lots of transformers over the years have failed burned out or loose wire or what ever do to the old Hum we think is normal . And that's not 60 cycles its at 120 cycles the sound you hear and part of the heat of that transformer .


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## socalelect (Nov 14, 2011)

All hail pipe runner all hail pipe runner


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## Next72969 (Dec 9, 2012)

socalelect said:


> All hail pipe runner all hail pipe runner


 this post will be deleted sooner or later :whistling2:


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## socalelect (Nov 14, 2011)

next72969 said:


> this post will be deleted sooner or later :whistling2:


ibtl


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> ... But if you have a core that vibrates at fundamental 1st 3rd 5th 7th odd HF you have a electrical problem and if you think vibration is not a issue your very wrong . ...


 Using the flex does not change the vibration of the transformer core.


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## piperunner (Aug 22, 2009)

don_resqcapt19 said:


> Using the flex does not change the vibration of the transformer core.


Well it eliminates transfer dampens it . Now we know this because we do sound test on our transformers per our specs . One way to lower vibration in a transformer is to lower the primary voltage which is done on some jobs .
low flux density is one way another is cut the laminations not like the standard cut laminations you get of the shelf or buy real expensive transformers with a core made of Metglas amorpous .
enclose it or move it out of the area . So whats your point you cant stop whats inside totally but you can have silence in a electrical room .That's the plan that's why we use flex because it eliminates issues that I guess you cant see clearly you must understand that flex is used by 90 % of contractors . I don't understand is the comments made on this forum about anything that is not code related its just a standard way to do stuff trust me theres more to it then the NEC.


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## chicken steve (Mar 22, 2011)

piperunner said:


> We purchase and not just our company theres plenty of contactors from 30 kva to 65 mega watt transformers yes HV mega watt transformers that are
> designed for silent operation just about every new job we do were installing more and more special cut laminated cores or spring vibration .
> Big jobs I hear are using low flux density cores this is whats new I cant help if the NEC is not up to date with what engineers want and the products on the market that folks with money need or want . Get educated heres what you need to read go to ABB look at what they build today .
> 
> .


So this next generation of Xformers are engineered to internalize vibration?

~CS~


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## MTW (Aug 28, 2013)

piperunner said:


> I don't understand is the comments made on this forum about anything that is not code related its just a standard way to do stuff trust me theres more to it then the NEC.


You should stick with running pipe from point A to point B and just stay silent about everything else.


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## don_resqcapt19 (Jul 18, 2010)

piperunner said:


> ...So whats your point you cant stop whats inside totally but you can have silence in a electrical room .That's the plan that's why we use flex because it eliminates issues that I guess you cant see clearly you must understand that flex is used by 90 % of contractors . I don't understand is the comments made on this forum about anything that is not code related its just a standard way to do stuff trust me theres more to it then the NEC.


You said in a previous post that using flex would reduce the transformer core vibrations...It will not and that is what I was commenting on.

Yes, the reason that flex is often required by the design specs for a transformer is the elimination of noise. 

As far as comments on the code in this thread, the original question was about what the code requires, it was not about how you, or I, or anyone else would do the installation. It simply is not a code violation to hard pipe a motor or a transformer, but the use of flexible connections for those items is the most common installation.


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## Big John (May 23, 2010)

You would think that post would pretty decisively end this thread. You'd be wrong. :laughing:


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## Peewee0413 (Oct 18, 2012)

Why hard pipe? Flex makes replacing a motor easier. I'm sure someone posted this, but didn't feel like reading back.


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## CFL (Jan 28, 2009)

I just hard piped a chiller in a room full of chillers connected with flex. It was much easier than using flex, and cheaper, and faster. I had people saying my connections would loosen up. I would say "what about all of hundreds of connections on the chiller?". As far as noise, it's a chiller room, not to concerned about that.


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## bostongtp (Apr 9, 2014)

And you shouldn't....did you even comprehend his statement?? I know you read it. We don't pipe in motors because like the majority said VIBRATION. These installs are supposed to last a long time, motors aren't exactly quiet, why would you attach it to a pipe?? So you can hear the customer complain when she hears 30decibels of motor vibrations?? It makes for a better install. Let's not re-invent the wheel.


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## Big John (May 23, 2010)

Somebody didn't read post #20. :whistling2:


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## bostongtp (Apr 9, 2014)

*oops*



Big John said:


> Somebody didn't read post #20. :whistling2:


Thought I was a hero bro. Sorry for the reiteration Bigjohn.


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## Peewee0413 (Oct 18, 2012)

Oh wow, another old thread notification...









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## Almost Retired (Sep 14, 2021)

Peewee0413 said:


> Oh wow, another old thread notification...
> 
> 
> 
> ...


and every time you tell us that it drags somebody else in with you
stop commenting and drowning us along with you please


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## Peewee0413 (Oct 18, 2012)

Almost Retired said:


> and every time you tell us that it drags somebody else in with you
> stop commenting and drowning us along with you please


Oh shat...Didn't think about that.....I'll remember next time...

Sent from my SM-S908U using Tapatalk


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## Wardenclyffe (Jan 11, 2019)

Twenty year old thread,...



https://www.automationdirect.com/adc/overview/catalog/wiring_solutions/bulk_multi-conductor_cable/continuous_flexing_motor_supply_cable


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## Peewee0413 (Oct 18, 2012)

Wardenclyffe said:


> Twenty year old thread,...
> 
> 
> 
> https://www.automationdirect.com/adc/overview/catalog/wiring_solutions/bulk_multi-conductor_cable/continuous_flexing_motor_supply_cable


lol...
I'm sorry guys....Blame it on Tapatalk...I'll most definitely look at dates before typing from now on...Its only on ET, I have tons of other automotive forums that don't do this random notification BS.

Sent from my SM-S908U using Tapatalk


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## Wardenclyffe (Jan 11, 2019)

I always get to the third or fourth post before the date hits me,...


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