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Stratmando · Jul 3, 2008, 01:56 PM

I would carefully dig around the conduit that goes out of bottom of Meter Can. It should have a ground rod and Wire Attachment/Clamp. Just remember, if not at ground potential, it may be live.

stanfortyman · Jul 3, 2008, 02:30 PM

Guys, let's not get lost in the fact that a ground rod does NOT ground anything. A ground rod will NOT prevent a shock, and in some instance could cause one.

If you run a 3-wire feeder to a detached structure; ie: no separate ground, and isolate the neutral, a ground rod will ABSOLUTELY NOT "provide" a ground. Any faults to this ground will NOT trip any breakers and will only send current into the earth and bring up worms.

A ground rod is required at ANY detached structure with a feeder. This is NOT the ground that we rely on to cause a breaker to trip upon a short circuit. It is for lightning protection for the most part.
The ground that causes a short circuit is the neutral bond in the main panel. This is carried to a detached structure by a four wire feeder with a separate ground and neutral, both being bonded at the MAIN panel.

Up until the latest NEC cycle a 3-wire feeder was allowed under certain circumstances to a detached structure. This let us run only an insulated neutral with the two hots to the detached structure and bond the neutral and grounds together. The sub-panel in this case is wired exactly as a main panel.
As with the 4-wire feeder a grounding electrode (such as a ground rod) is required.

KISS · Jul 3, 2008, 05:56 PM

I don't think we determined that this is a "detached structure" because it appears to be connected by a breezeway.

stanfortyman · Jul 3, 2008, 06:35 PM

I see. I have to humbly admit, I did not read every word of every post.

KISS · Jul 3, 2008, 07:01 PM

I need to edit mine: I meant to say "we have not determined that this is a "detached structure" since it is connected by a breezeway. Would you consider it "attached" or "detached"?

stanfortyman · Jul 3, 2008, 07:12 PM

That's always a tough call. I really think it depends on the structure.

I think there are only a very few instances where it could be considered detached.
If it is just a small piece of roof between two obviously separate structures I'd call it detached.

KISS · Jul 3, 2008, 07:20 PM

Did you mean attached rather than detached in the following sentence?

Originally Posted by stanfortyman

I think there are only a very few instances where it could be considered

Originally Posted by stanfortyman

I think there are only a very few instances where it could be considered detached.

.

chiefengineer · Jul 3, 2008, 09:49 PM

Originally Posted by stanfortyman

That's always a tough call. I really think it depends on the structure.

I think there are only a very few instances where it could be considered detached.
If it is just a small piece of roof between two obviously separate structures I'd call it detached.

Background on the breezeway:
It was built/connected to main house (about 20 feet, 6 feet wide) with steel roof.
The steel is not connected to the steel roof of the house (which is galvalume, but the breezeway is bonded to the garage only).

The main house panel feeds the garage panel by a 100A breaker from what I can see. Didn't know there was such a thing, but magic marker says so.

The house and garage "meet" in the lightswitch in the house's mudroom. This is 2 blue plastic boxes separated and one coverplate (plastic).

In terms of digging for a rod, that seems logical... but I also have a whole lot of panels looking identical some of which the coop told me they put in... all in plastic disappearing to earth... maybe it is so complete nothing shows... or maybe they think the transformer protects the circuits?

Stratmando · Jul 4, 2008, 05:28 AM

I haven't read every post either, Did you try turning off breakers 1 by 1 to determine the circuit it is on?
I only mention the ground rod as I thought it was mentioned not present.
The breezeway light has to have both switches ON? Is one switch switching a neutral?

donf · Jul 4, 2008, 09:52 AM

Hi,

Just a point of clarification. You said, "but I also have a whole lot of panels looking identical some of which the coop told me they put in..."

By Co-op, do you mean an Electrical Co-op, or do you mean a Co-op as in a group of co-op owners?

KISS · Jul 4, 2008, 04:31 PM

There is no point looking for grounds when there isn't any. i.e. garage panel
It's obvious it's not there.

The garage panel is in a "detached" structure.
The garage panel needs a ground from the main panel.
The garage panel needs a ground rod.
The garage panel needs to have the grounds and neutrals separated.
The garage panel needs the wiring cleaned up - no sheaths inside the panel.

That out of the way:

The 100 A feeder goes through a conduit?
If so, is it plastic or metal?
If it's metal is is continuous to the main panel?
If so, this could be your "missing ground"
What's the OD of the (wire+insulation"?
What's the wire gauge?
What's the size of the conduit?
Do you think you can fish another wire through the conduit to the main panel?
It can be sized smaller.

KISS · Jul 4, 2008, 04:35 PM

Digging for a ground rod connnection.

Not a useful exercise.

Garage panel doesn't have one.

You need a picture of the inside of the main panel.

You need a picture of the inside of the box next to the meter.

The inside of these components can revel the possibility of a ground rod like the garage panel did.

chiefengineer · Jul 5, 2008, 10:46 AM

Originally Posted by KeepItSimpleStupid

Digging for a ground rod connnection.

Not a useful exercise.

Garage panel doesn't have one.

You need a picture of the inside of the main panel.

You need a picture of the inside of the box next to the meter.

The inside of these components can revel the possibility of a ground rod like the garage panel did.

Thank-you for the excellent analysis. I live 30 miles from the gulf and things blow
In quickly, but I managed to look at some radar and get the panel back together
Before a monsoon hit (housePanel.jpg--attached).

As you can see (unless I don't know what I am seeing), there is no main shut-off so
I would have to have a service call to the utility to shut anything off to work on this.

I am guessing the panel is grounded via the meter which I can't open. I have also attached a pic of the rods entering the ground... the meter is the only thing with
Conduit entering the ground... the panel runs are plastic at the point of ground entry
(at least). But no rods anywhere in sight.

The panel has mud dawber nests and cobwebs I would clean up if I could shut it off, and there is a large bare wire touching the panel on
The right. There is no conduit to the garage, just large gauge black encased wire going
Through plastic... if there is a ground to the garage from the house I don't see where it is attached to the house panel. This
Had to be an underground run of about 100 ft. almost entirely under a building slab (the garage). Furthermore the garage panel is in a central plasterboard stud wall far from
Any potential outside grounding location. It would appear I'd have to go up out the panel
Through the attic and back down... and although there's a shut-off in the garage, there's none for what feeds it (?).

My next move will be to move wires as suggested in the garage panel.

donf · Jul 5, 2008, 11:21 AM

I'm new to this thread, but I'm curious if you made sure the switch plate was properly grounded to the switch?

You ground the plate by using the bare wire ground to the screw in a metal box. If the box is plastic, attach the ground wire to the switch's grounding screw. Once the switch is grounded, then the metal faceplace will be grounded when it is mounted to the switch's yoke.

KISS · Jul 5, 2008, 11:45 AM

Plastic is conduit. This looks like an outside panel which provides a bunch of disconnects to smaller panels. I'm not sure what I'm seeing here either, but if you can get a vacuum cleaner hose and clean out the cobwebs, and take another picture that would be great.

It won't bite down at the bottom. That doesn't look like an enclosure appropriate for outside.

KISS · Jul 5, 2008, 02:33 PM

This looks like your main panel. There is a screw to the right of the large middle cable coming in from the top. This looks like the bonding screw.

If you get the cobwebs away, we can see how many wires are going to the meter base.

From what we seen so for, the existence of a ground rod is slim.

Is it time to put a lid on this can of worms?

KISS · Jul 5, 2008, 02:35 PM

The outside enclosure should probably be rated NEMA 3 or NEMA 3R. I don't think it is.

See: http://www.admeng.ca/documents/Nema_Enclosures.pdf

KISS · Jul 5, 2008, 02:40 PM

This would be the likely place to feed the garage panel.

chiefengineer · Jul 5, 2008, 03:08 PM

Originally Posted by KeepItSimpleStupid

There is a screw to the right of the large middle cable coming in from the top. This looks like the bonding screw.

I thought of blowing the thing out before the big rain hit, I could let the T-storms
Wash the whole thing out but it'd probably kill my box. (see my forecast... little
Likliehood I'll get in there soon). Yes, the box is old and bent... Square D 20 yrs. Old,
Put in by the coop.

The bonding screw on the top middle is a ground? That would explain why I just did
The following which seems to have "solved" the grounding mystery:

I had time to cap all the loose wires with tape
In the garage panel, then moved the 220V ground
Wire that was on the right side ground bar to the
Right side neutral bar.

I also carefully inspected the power coming from the
Outside panel's 100A breaker and found the wires to be
Of an immense gauge... probably 6.

There were 3 on wires on the uppermost
Take-off that led from the bottom of the panel, yet only
Two coming from the main panel breaker. This led me to suspect that
One of them is a ground(!) leading somewhere into the dirt
That I can't see... possily because they built onto this garage
Structure behind it and left the ground underneath(?).

I checked a couple of outlets and got 115V ground to hot after
This switch.

chiefengineer · Jul 5, 2008, 03:15 PM

Originally Posted by donf

I'm new to this thread, but I'm curious if you made sure the switch plate was properly grounded to the switch?

You ground the plate by using the bare wire ground to the screw in a metal box. if the box is plastic, attach the ground wire to the switch's grounding screw. Once the switch is grounded, then the metal faceplace will be grounded when it is mounted to the switch's yoke.

This seemed like an excellent idea to me, as I had just done this... see my attached pics.

After I switched the 220V wiring in the garage
panel to look identical (all 3rd wires to neutral bar)
I retested the breezeway switches and got identical test
results to the original test.

I pulled the garage switch controlling the breezeway light
and took two pictures (attached). There are two groups of
romex for this switch (my analysis may be wrong here):

Romex 1 = Ground on neutral terminal on left side
Neutral wire to neutral terminal on right side
Hot married to Romex 2 neutral
Romex 2 = Hot to hot terminal on left side
Ground to ground
Neutral married to Romex 1 hot

Oh, and one thing I noticed was that the ground screw was on
the top of this switch, which after seeing these high res
pics indicates this switch is upside down. Do you think
the installers noticed such a thing... or should I proceed
to rewire this as is except right side up?