Note that full coverage of how to install a grounding electrode
	system is well beyond the scope of this FAQ.  The comments made
	here are primarily so that the reader understands what it is
	for, and some of its characteristics.

	The grounding electrode system is a method by which the neutral
	and grounding conductors are connected to the common "earth"
	reference.  The connection from the electrical system to the
	grounding system is made in only one place to avoid ground
	loops.

	The grounding electrode system is _not_ intended to carry much
	current.  Ground faults (Ie: hot to grounded case short) are
	conducted down the ground wire to where it is interconnected
	with the neutral and hopefully the breaker/fuse trips.  The
	grounding electrode does not participate in such a situation.
	While the conductors involved in this are relatively large, they're
	sized for lightning strikes and other extremely short duration
	events.  The grounding electrode system is specifically _not_
	expected to have enough conductivity to trip a 15A breaker.

	The grounding electrode often has a moderately high
	resistance.  For example, according to the NEC, an acceptable
	ground electrode system may have 25 ohms of resistance - only
	5A at 120V, not enough to trip a 15A breaker.

	A grounding electrode system usually consists of a primary
	grounding electrode, plus possibly a secondary electrode.  A
	primary electrode can be (if in direct contact with the earth):
	10' of ground rod.  10' of well casing or metallic water pipe
	(must be connected within 5' of pipe entrance to house).  20'
	of copper wire buried in the bottom of the footings.  A
	secondary electrode will be required if the primary is a water
	pipe or (NEC) if the primary electrode is >25 ohms to the
	dirt.


User Contributions:
Dev
Dec 21, 2011 @ 12:00 am
In a fire protection circuit, circuts are shown witha no example 6,8,4etc. what it mean?these circuits are connected between smode detector,junction box etc
kevin
Dec 24, 2011 @ 12:12 pm
My daughter dropped a small necklace behind her dresser. The necklace crossed a plug terminal and shorted the receptacle.

I bought a new receptacle and installed the same. I still have no power  I suspect there could be a bigger problem,this is aluminum wiring.

I've killed the breaker and call an electrician but am curious as to what happened.P.s. there is a dimmer switch on the same circuit.
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