Motor lead taping

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MattS87

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Yakima, WA
No issues here just curious on what everyone else does. The NEC does not have a standard for the taping of motor leads but I was taught; cambric, rubber tape, finished with 33+. However in the past 2 years we have transitioned to a newer product http://www.alliedelec.com/thomas-betts-tbft201-36/70092452/ which replaces the cambric and rubber tape. Not only does it make for a faster install time but it comes off a whole lot easier than the rubber tape. Has anyone else used this, or how do you tape up motor leads?
 
I don't use the cambric...just use 130C and 33+ for the ones we tape, which are only the smaller ones now. For bigger ones, we use the Raychem Gel Caps.

For those who don't like not using the cambric first, I have never had any trouble removing my tape, assuming that the 130C was installed per the instructions...sticky side out. You just cut a lengthwise slit in the tape and grab it with two pairs of pliers, and open the splice up...it comes completely off with no issues.
 
I have never understood the extreme measures some electricians take with motor lead connections. Wire nuts taped up so they don't vibrate loose work fine for smaller motors.

Nut bolt and tape works well too, although I have never quite understood why so many electricians use so many layers of insulation. A couple of layers of black tape is adequate insulation.
 
petersonra said:
Nut bolt and tape works well too, although I have never quite understood why so many electricians use so many layers of insulation. A couple of layers of black tape is adequate insulation.
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I don't know what a nut bolt is but if you mean a split bolt and tape I can tell you why the extra insulation. A motor vibrates and the splice/tap may be there for many years and you worry the vibration may cause the bolt to rub through a bit of insulation.

I'm not sure what black tape is either. Many types of tape are black. Many of those will dry out and crack in no time at all. It's important to use the right type of tape ( all tape is not created equal even if it's black ).
 
growler said:
I don't know what a nut bolt is but if you mean a split bolt and tape I can tell you why the extra insulation. A motor vibrates and the splice/tap may be there for many years and you worry the vibration may cause the bolt to rub through a bit of insulation.

I'm not sure what black tape is either. Many types of tape are black. Many of those will dry out and crack in no time at all. It's important to use the right type of tape ( all tape is not created equal even if it's black ).
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Nut, bolt, and tape is a connection made with ring tongue terminals connected together with a nut and bolt, and then insulated with black tape, although the color does not matter. It could be some other color if you wanted to pretty it up some. http://www.tapeplanet.com/Pink-Electrical-Tape-10-pack-7-mil-3-4-in-x-66-ft-p/el766clpi10.htm
 
petersonra said:
Nut, bolt, and tape is a connection made with ring tongue terminals connected together with a nut and bolt, and then insulated with black tape, although the color does not matter. It could be some other color if you wanted to pretty it up some. http://www.tapeplanet.com/Pink-Electrical-Tape-10-pack-7-mil-3-4-in-x-66-ft-p/el766clpi10.htm
Click to expand...

I have seen plenty of these fail because of not using cambric and/or rubber tape. If all you do is 10HP and less ok, but around here we have as high as 12000HP. Granted when you get that big everything is bus bar but tape up a 300HP motor with 2 layers of tape and tell me how long that lasts :)
 
I worked for a machine tool builder and we used the nut and bolt method and then wrapped with 33+ for small motors. For large motors we used nuts and bolts but heat shrinked instead of tape.
 
MattS87 said:
I have seen plenty of these fail because of not using cambric and/or rubber tape. If all you do is 10HP and less ok, but around here we have as high as 12000HP. Granted when you get that big everything is bus bar but tape up a 300HP motor with 2 layers of tape and tell me how long that lasts :)
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It lasts until it fails:D

You didn't say what type/thickness of tape would be used either.
 
I became a J-man at a steel mill. Motors up to and including 10HP we used ring tongues and stove bolts (courser thread than machine screws, square nuts). Larger all got Kearneys (split bolts). If you used a wire nut on anything (and got caught), you could lose your job.

Varnished cambric went over the connection, then a layer of at least 5 wraps of 3M #130 rubber tape, finished with 3 wraps of 3M #33+ vinyl tape. we all carried all 3 hanging on the tape chain of our tool belts at all times.

As it was taught to me, the varnished cambric was so the NEXT GUY didn't cuss you out, because it wouldn't stick to the connection, even after years of heat and oil etc. The rubber tape was for protection against vibration of the connection against the side wall of the peckerhead. The black vinyl tape protected the rubber tape from coming unraveled before it could fuse. Some guys from other jobs came in with doing the "sticky side out" routine on the rubber tape, they were told to change. The reasoning I heard given was that over time and heat, the rubber is designed to fuse into a solid mass, the glue was only there for the initial install. So without the cambric it would still be difficult to remove. This may have been somewhat unique to us being a steel mill where more heat was always present. Later when I did a lot more pump work, I began using the sticky-side-out routine and no cambric (I went to a supply house and asked for some once, got a blank stare), never experienced a problem.
 
Jraef said:
I became a J-man at a steel mill. Motors up to and including 10HP we used ring tongues and stove bolts (courser thread than machine screws, square nuts). Larger all got Kearneys (split bolts). If you used a wire nut on anything (and got caught), you could lose your job.
Click to expand...
We use ring terminals and bolts no matter how large the motor it. I have never seen a motor around here connected with a split bolt. We also did not use wirenuts.

Taping the connections is labor intensive and so I started using the Raychem Gel Caps a number of years ago for the larger motors. They don't fit in the motor junction boxes unless the motor is over 5 hp, but they are cost effective with our labor rates. The maintenance guys love them when they have to change a motor....just open the snap clip and pull them off. The silicone gel insulation says in the outer sleeve as you pull the sleeve off the connection, and they are re-useable.

Varnished cambric went over the connection, then a layer of at least 5 wraps of 3M #130 rubber tape, finished with 3 wraps of 3M #33+ vinyl tape. we all carried all 3 hanging on the tape chain of our tool belts at all times.

As it was taught to me, the varnished cambric was so the NEXT GUY didn't cuss you out, because it wouldn't stick to the connection, even after years of heat and oil etc.
Click to expand...
Some of the messiest motor connections I ever took apart were made using the adhesive type varnished cambric as the first layer. That was used in a number of the plants around here. As far as using the cambric, I was told we needed to use it too, but after I showed them how easy the connection is to remove when you wrap the 130C sticky side out, they no longer asked me to use the cambric.
The rubber tape was for protection against vibration of the connection against the side wall of the peckerhead. The black vinyl tape protected the rubber tape from coming unraveled before it could fuse.
Click to expand...
Yes, you needed the plastic to keep the rubber in place.
guys from other jobs came in with doing the "sticky side out" routine on the rubber tape, they were told to change. ...
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They were doing it per the instructions if they were using 130C.
 
Surprised nobody uses Polaris grays in motors.

Have often thought the labor savings on those would far outweigh the initial cost.

No idea how they would stand up to vibration, though.
 
iwire said:
Going to be honest here, I have never read tape instructions. :)
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Often I don't either, but I came across that somewhere and it does work well when you do that.

A long time ago, at a parent teacher conference, the teacher commented that my son does not always read the directions before starting something....I commented that dad doesn't do that either....teacher was not impressed.
 
Jraef said:
I became a J-man at a steel mill. Motors up to and including 10HP we used ring tongues and stove bolts (courser thread than machine screws, square nuts). Larger all got Kearneys (split bolts). If you used a wire nut on anything (and got caught), you could lose your job.

Varnished cambric went over the connection, then a layer of at least 5 wraps of 3M #130 rubber tape, finished with 3 wraps of 3M #33+ vinyl tape. we all carried all 3 hanging on the tape chain of our tool belts at all times.

As it was taught to me, the varnished cambric was so the NEXT GUY didn't cuss you out, because it wouldn't stick to the connection, even after years of heat and oil etc. The rubber tape was for protection against vibration of the connection against the side wall of the peckerhead. The black vinyl tape protected the rubber tape from coming unraveled before it could fuse. Some guys from other jobs came in with doing the "sticky side out" routine on the rubber tape, they were told to change. The reasoning I heard given was that over time and heat, the rubber is designed to fuse into a solid mass, the glue was only there for the initial install. So without the cambric it would still be difficult to remove. This may have been somewhat unique to us being a steel mill where more heat was always present. Later when I did a lot more pump work, I began using the sticky-side-out routine and no cambric (I went to a supply house and asked for some once, got a blank stare), never experienced a problem.
Click to expand...

This is how I started out as well. The j-man i was taught from said if the connection doesn't look like a light bulb then it fails in his book. I have been know to over-tape stuff, but I'm one of those 'do it once' kinda guys i guess. As far as directions, I'm guilty of not reading them until I do something wrong.
 
MattS87 said:
This is how I started out as well. The j-man i was taught from said if the connection doesn't look like a light bulb then it fails in his book. I have been know to over-tape stuff, but I'm one of those 'do it once' kinda guys i guess. As far as directions, I'm guilty of not reading them until I do something wrong.
Click to expand...
Is it ok if the "light bulb" looks like a spiral type compact fluorescent lamp?:cool:
 
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