OT:Electrical Question

I am learning electrical and automation and have a somewhat basic question.

When replacing large motors like 200 hp and above and using split bolt connector they have to be insulated. I was told to wrap the connector first with scotch 2520 varnished cambric tape then wrap it with rubber splicing tape which is tacky on one side only then go over it with scothc super 33 electrical tape. Does this sound correct?

The rubber tape they carry here is scotch 130c linerless rubber splicing tape and they also have scotchfil electrical insulation putty which is rubber tape that is sort of tacky on both sides.

What is the main difference between the linerless rubber tape and the scothcfil putty tape?

Is this the correct method and order of doing this. The fellow that told me this way is not too sure of himself so I figured I would ask.

There are many ways of doing this yours will work. I like to back wrap the split bolt first sticky side out with 33 so as when disconnecting (cutting off tape) the split bolt is not embedded with sticky stuff

Look at this from 3M.

http://multimedia.3m.com/mws/mediaw...Tc4xTVEVuQEcuZgVs6EVs6E666666--&fn=IS5302.pdf

or this:

http://energy.te.com/getDocument.aspx?PRD_ID=2045

I use Burndy insulated connectors. Strip, insert, tighten set screw, push screw caps on, done.

When I had time and had the correct size in stock I would use splicing setups made for motor use like what @brucechase posted.

When I was in a hurry and I was out of motor splices I did it like @BCE123.

The Burndy connectors that @Alaric posted are nice as well. I used them several times, but I had trouble getting them in the area where I lived at the time.

Alaric said:

I use Burndy insulated connectors. Strip, insert, tighten set screw, push screw caps on, done.

Click to expand...

I loudly second that!!!! Burndy's are sweet. If you ever need to take them off, (and you have dealt with the high voltage tape and all that fun sticky stuff), these things are worth their weight in gold.

-Dave

It should go without saying, but check the voltage rating on any insulated connector system you may use, especially since a 200HP motor might be a medium voltage (>1kV) motor.

I was told that when using the burndy and polaris type connectors they were good fr 1 or may 2 uses only. if they are used past that they tend not to hold torque the connection gets loose and stuff releases smoke. Is there anything to that?

I've heard that too Tim. I usually replace them if they are pretty beat up or the setscrews don't turn like new.

This is how I, and most of the other guys in the shop do it the other way. I only use this method if there are already crimps on all the leads and I don't want to cut and restrip the(usually) already short wires to use insulated taps instead.

Wrap with varnished cambric at least 2-3 inches down past the end of the crimp onto the wire. Then cut 2-3 strips of Scotchfil insulation putty about 4-6 inches long or so depending on the size of the connection. I take these and lay them over the end of the wire covering the sharp corners of the crimps. So if you have all the wires pointed at you, this insulation putty looks like a plus sign overlapping the ends of the wires.

Then, get out your roll of 130C, I like the 2" wide stuff unless the peckerhead is real tight, and start wrapping at the bottom just above the cambric, wrap around all the scotchfil making sure you are stretching the 130c tight enough it turns gray while you apply it. Wrap until your have a nice tight rubber ball that you can feel no sharp corners through.

When you're finished with that, start at the bottom again with Super 88 going as low as you can but staying on the cambric, I usually leave a little cambric exposed, and wrap to the top and back down to the bottom.

That's it, you're finished.

Forgot to mention, some of the guys skip the scotchfil and just use rubber tape. But I think it saves quite a bit of time not having to wrap that much more rubber tape on it. Either way is fine.