Submitted by: Kerry Johnson

"What's Wrong Here?"


[This message has been edited by Joe Tedesco (edited 03-04-2002).]

Installer gets an "E" for effort! Wouldn't it have taken less effort to spend 25 cents at the local hardware store for a nipple. As opposed to $10 in labor notching that piece of copper, or is it a copper raceway? I guess all this is support for properly trained and licensed personel!

Some NEC I see violated:
Top left
250-148
370-17B

Bottom left
370-29

Right
370-17B
110-12
What did I miss?

Great calls wirewiz

I would also call 99 or 02 NEC Section 300-14. last sentence for lower left.

" .... Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening."

What else?

Does anyone have any additional references?

Thanks Joe
Would the top left require the same as 300-14? If the conductors were ever tapped there would not be 6 inches available from each point of entrance?

Yes, I agree and the issue would also come up when an extension ring was added.

That's what is behind the rule cited above. If the wires pass through unbroken, they are not required to meet the 6 inch rule. A proposal was sent in, and was rejected when an electrician asked that the length of the "loop" be 12 inches so as to avoid the problem with less than 6 inches.

Upper Left

After talking to Kerry. I learned that the conduit entering the back of the box stubbs through a block wall. Instead of comming straight into the box, it comes in at an odd angle. Therefore a connector wouldn't have been square to the box. That's propably when someone got the idea to notch the conduit and bend it over.

During the remodel this "system" was removed.

What is the voltage?
Would a bonding bushing be required for the broken concentric ring?

Redsy:

If this was service equipment supplied at any typical building supply voltage, the code would call for bonding bushings where their were concentric or eccentric rings still present, and when the voltage is over 250 volts to ground the bonding could only be accomplished in the same manner for services. See 2002 NEC 250.97

We should also remember that so-called "donuts" are not going to satisfy the bonding requirements - they are only used to correct a mistake!

Voltage at the broken knockout is 208V 3P. It is branch circuit wiring feeding a HVAC condensing unit. Does it need a bonding bushing? If the knockout was still intact, would a bonding bushing required?

John:

No, because the voltage to ground is not over 250 volts, but a bushing that will conform to 300.4(F) would be required.