Add FPN to 250.130(C)

[petersonra]

Re: Add FPN to 250.130(C)

so do they plan to undo things they required beyond the outlet?

 

[charlie]

Re: Add FPN to 250.130(C)

If everyone would see it our way, it would be a done deal. We have only one vote on each panel. You should have seen all the discussion on Panel 10 to get rid of appliance and extension cords.

 

[tom baker]

Re: Add FPN to 250.130(C)

There is a very good comment by the Edison Electric Institute about listing of decorative lighting and why this does not belong in the NEC. Charlie is a rep of that institute. We have a much longer NEC this time due to the requirements to list extension cords, GFCI for vending machines and so on, these requirements do not belong in the NEC. There are product listing requirements.

 

[mc5w]

Re: Add FPN to 250.130(C)

Perhaps the term "equipment grounding conductor" should be changed to "equipment grounding and bonding conductor". Part of the purpose of equipment grounding is that a lot of things such as concrete floors, concrete walls, plumbing, and so forth have natural connections to the earth.

The safety bonding system does need a reference point and the most logical is to use the earth and if it exists, the system neutral or corner grounding of the system.

Natural connections to the earth also pose a problem when current flow in the soil, such as from failing underground wiring, partially energizes all kinds of things. I encountered an instance where properly grounded water supply plumbing and a washing machine has nasty tingle voltages on them. The problem was that current flow from a failing underground power line was partially energizing the drain pipes and concrete floor respectively. The power line construction was cloth covered rubber inside of ungrounded galvanized steel conduit that was rather rusty. Grounding and bonding the conduit would not have helped because it was so rusty.

In his book "Old Electrical Wiring" David Eli Shapiro relates an instance where electricity was crawling up the slime inside of a plastic drainpipe for a shower. He never did find the source. I also know a mobile home park that has tree roots and grass roots that are penetrating the O-rings of gasketed 3034 PVC sewer pipe. Plus, concrete manholes and handholes are also a point for soil electricity to enter. Evidentally, we need to communicate to the plumbing and sanitary engineering people that gasketed sewer pipe joints need to be wrapped with copper coil or other effective means of discouraging plant roots.

As electrical systems age there will be more in the way of these kinds of problems.

 

[mc5w]

Re: Add FPN to 250.130(C)

As for expanding GFCI requirements, some things are ill thought out. For instance, most older refrigerators are incompatible with GFCI protection because the compressor has too much insulation capacitance. This is no more of a hazard than how a 480 volt motor **WILL** have a nasty tingle voltage if it is not grounded properly. A good alternative would be to have an extra wire that is hooked up to a relay that does continuous monitoring of the equipment ground - this is one of the things that is done in mines to make extension cords up to 13,800 volts that are as safe as breakfast food. The equipment ground is what keeps you from getting shocked by a refrigerator.

Similarly, the engine block heaters and wiring for diesel trucks does not work with GFCI because salt water forces its way in at 55 MPH. The salt water creates too much leakage current even during the summer and early fall. Again, no hazard if the truck is grounded. If you are worried about electrocution hazard from cord cuts what you really need is to put the cord in liquidtight flexible metal conduit ( done in factories and now legal ) or to use shielding of the conductors regardless of voltage which is what is done in mines in addition to monitoring the equipment ground.

Sure, GFCIs are cheap but they also work on the premise that using the human body as the equipment ground is acceptable. For that matter, a 50 amp or 60 amp cord on a jobsite is just as hazardous as a 20 amp cord. Just because there are FEWER 50 amp or larger cords does not diminish the hazard level not that cords in this size are not available in cheap residential grade cords that have a J in the designation.

NEC does have some business regulating cords because of the extent that they are used in factories, construction sites, outdoors, carnivals, exhibition halls, stages, older houses, and what have you.