680.74 (again)

Status
Not open for further replies.
ryan_618

ryan_618

Senior Member
Location
Salt Lake City, Utah
I plan on submitting a code change for the 2008 on 680.74, but I would like some opinions before I do.

In the portion that discuss double insulated motors, it tells us that they SHALL NOT be bonded. I would propse to change this this to IT SHALL NOT BE REQUIRED to bond them.

As written, it would be a violation to bond a double insulated motor. While I think there is probably no reason to bond it, it should not be a vioaltion to do so. I can't think that bonding them would be detrimental, but I am not 100% sure on that. does anyone have anything to add?
 
Re: 680.74 (again)

Ryan: You have hit on one of my favorite subjects.

The purpose of the double insulation concept is to eliminate any possible contact with a ground wire or surface.

Think of bare handed live high voltage work. A lineman is perfectly safe as long as there is no complete circuit.

I always say; do not provide the other half of a lethal circuit by indiscriminate grounding.

You are thinking Ryan, but insulation and isolation is safer than grounding.
 
Re: 680.74 (again)

Mike Holt has made that comment, Bennie may of as well.

And regarding "Think of bare handed live high voltage work. A lineman is perfectly safe as long as there is no complete circuit" posted by Bennie. An accepted menthod to maintain very high voltage lines (112 kV) is with a chopper and a work platform. The worker wears a mesh suit to reduce static electricty. Maintenance can be done on the lines without shutting down.

[ February 28, 2004, 01:38 PM: Message edited by: tom baker ]
 
Re: 680.74 (again)

Just to reiterate what Bennie has said, it would defeat the purpose of the double insulated motor if you were to connect to the motor with the bonding conductor. So changing the wording to that section would not be a good idea and would not be accepted as a change anyway.

Pierre
 
Re: 680.74 (again)

While on this subject, everyone with crawling babies please tape up the co-ax connector on the back of TV sets supplied by cable. Also check the attachment cords for exposed strands of copper wire.

A baby was electrocuted by touching the grounded connector while standing on the cord that had one strand exposed.
 
Re: 680.74 (again)

Tom Baker. I have done that type of high line work. Also have bonded from a fixed platform and aerial device. When we had to repair a problem at night you would see the blue devils running all over the person that was bonded on. God I miss linework.
 
Status
Not open for further replies.
Top