wiring a sub panel in garage

[Glotharg]

I have a problem that I don't understand...
I ran 60 amp service to the garage. I used #6 wire, 1 black, 1 red 1 white, from a 60 amp breaker in the main panel, attaching the white (common) to the common lug into a 100 amp service sub panel out in the garage... red to one side, black to the other... and white to the common insulated lug.

Outside the garage, I have a 6 foot... maybe it's 7ft... copper pole buried in the ground and a solid copper wire from the panel attached to it. (Code says I need 2... but I have one for now until I finish)
Somehow, I am getting a completed circuit once I connect the sub panel to that ground wire going outside...

There is no continuity between the common lugs and the sub panel.. everything is ok... until I connect the ground to the sub panel, then I get a short somewhere...

I even disconnected the ground lug bank so it would act as an 'insulated' ground lug...not touching the panel at all, and connect the bare wires to it, I still get a reading of 119v...

The garage is all romex 3 wire and plastic boxes. I don't understand what my problem is...

I disconnected the wires from the main panel... nothing is broken or shorting in the underground lines... I am baffled.

[HayZee518]

a sub panel needs four wires. two hots a neutral and an equipment ground. the neutral bus in the sub panel is isolated above ground - no connection between it and the cabinet ground. the ground wire, the fourth wire from the main gets tied to an auxillary ground bar that is fastened to the cabinet. at your main. black hot to a 2 pole breaker, the red to the other breaker terminal. both the neutral and bare equipment ground gets connected to the neutral bus in the main panel only.

[Glotharg]

ahhh.. so I am missing a wire... will that's gonna suck trying to fish that through by itself... damn..

[HayZee518]

60 amp service to a sub panel #6 THHN. #6 is good for 65 amps. easiest way is to tie a stout string onto a wire, pull it back through, tie on another wire and pull it back to the panel. use some "snot" if you have a few turns.

[Glotharg]

I ended up pulling it all out, and doing it over again. I went red and black to the 60 amp breaker from the main, into my left and right side of the sub. does my main have an insulated common and bound ground bank? maybe thats why I am getting continuity on the sub panel box and common... I will have to look at it again.. sigh..

[HayZee518]

sub panel

take a look at the following drawing. you will have either the top drawing or the bottom drawing. the neutral bonding screw or jumper is used in the main panelbox ONLY. It is NOT used in the sub panel. the neutral in grey connects to the isolated neutral bar. the other equipment ground [ brown] goes to the aux grounding strip

[Speedy Petey]

Can you post a pic of how you wired the sub-panel?
I suspect you simply wired something wrong.

[Glotharg]

I will take a pic and post it in a bit..

[Glotharg]

ok.. the very top wire to the left, is the ground from the main box to this box, the #6 white is unbound... you know the red and black... The thicker white at the bottom left is the ground that goes outside to the 7' grounding rod.
At this point, I don't get a shock anymore if I touch the garage door rails... If I go ground to the outlet.. then ground to the garage rail.. I don't get continuity... If I go live outlet side.. to garage door rail.. I got 120v... is that normal?
I think I got it now...

[jnaas2]

Where does the wire in the top left corner go to

[Speedy Petey]

From what I can see it is wired right.

Is that ground from the feeder white for a reason? Is that paint or something?

[Glotharg]

the top left white 12 ga wire goes back to the bound ground to the main... same ground lug as the #6 common.

[Speedy Petey]

How is that run? It looks like it comes from the same cable.
If it is separate that is not good.

[HayZee518]

ok, what you have is a main lug sub panel. the hots are where they belong. the neutral is not bonded to the chassis or cabinet ground. the aux ground is connected via the bare ground. branch circuits connect with the neutral to the neutral in the panel, the equip ground goes to the aux ground. you should be able to read 240 plus or minus between the black and red wires. you should read 120 volts between either leg to neutral NOT the equipment ground.

[Glotharg]

That's the problem.. I am getting 240 +/- across the hots..I am reading about 119 from either hot to the unbound Nutral lug bank. But I am getting about 110 from either hot to the bound lug bank.....

My circuits are all 3 wire romex... black to the breaker, white to the unbound nutral lug bank, and bare to the bound lug bank.

From the main:
I have 4 wires coming from the main panel, the 3 braded #6 wires. 2 hots from the 60amp breaker, and the white from a bound nutral lug bank. The #12 solid white wire also from the same bound lug bank.

in the sub panel, the solid #12 wire goes to the (far left, top) bound lug bank.
The red and black hots go to each side and the #6 braded white nutral, goes to the unbound Nutral lug bank.

What goes wack-job, is when I hook up the 2nd white braded wire comming from the 7' burried grounding rod, to the bottom of the bound lug bank.

my brain keeps telling me that there needs to be an unbound lug bank in the main panel, but there isn't.

Is it because I only have one earth ground? I know I need to drive another pole into the ground, and connect it to the first one.. but it shouldn't make that much of a difference...