Electrical code Q

[Dean Hoffman]

There has to be 20 feet or more of 1/2" rebar. The pieces can be fastened with the regular rebar ties. I think one is done once the 20 minimum is reached. No need to fasten all the rebar. Rules are tougher for livestock buildings. I would think the concrete crew could handle that part. The bad thing would be waiting for an inspector. We don't have inspection for what I do in Nebraska so I can't speak from personal experience. I've been told they do want to actually see the rebar before the pour. This is from the 2008 U.S. Code:

2008 NEC?250.52 Grounding Electrodes.

(A) Electrodes Permitted for Grounding.

(3) Concrete-Encased Electrode. An electrode encased by at least 50 mm (2 in.) of concrete, located horizontally near the bottom or vertically, and within that portion of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 6.0 m (20 f.t) of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (½ in.) in diameter, or consisting of at least 6. 0 m (20 ft.) of bare copper conductor not smaller than 4 AWG. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means. Where multiple concrete-encased electrodes are present at a building or structure, it shall be permissible to bond only one into the grounding electrode system.

End quote. .

From:

That is the national code. Localities can change it as they please.

[Don Klipstein]

Either that was a capacitive source (brighter lightning-like spark) or the current was a couple milliamps. The capacitive source is a different story - the quantity of concern is joules. I seem to think that a somewhat common figure for threshold of significant or high chance of electrocution from that is 10 joules, and my father made me not store more than 1 joule in a high voltage capacitor until I was 17 or so. I seem to think that in a monitor or a TV set, a couple to a few tenths of a joule is stored. (I would not bet my life on surviving whatever that actually is.)

Sounds to me about 26-30 KV. There is a need for lower voltage - to reduce production of X-rays and to make the X-rays easier to block with a thick CRT face made of leaded glass.

High frequency reduces the bite. I describe that in:

Best Regards,

[Tony]

Yes, right at the ground rods I disconnected the ground wire going to the main panel. I didn't separate the 2 rods. The hot to the two rods did indeed trip the 30 amp breaker. To be fair though, it was after a few days of heavy rain.

[jamesgangnc]

I'm reminded of that old popular science "worm collecor" project that involved two ground rods, a light bulb and 120vac. :-)

[Steve Barker]

yes