This is a picture of my interior breaker panel.

I have an exterior breaker panel that houses a 100 amp main breaker
Which turns the interior (picture shown) off.

I need to change the metal block that the large white wire (C) is connected to.

Once I turn off the exterior main breaker...
How do I check to make sure the interior breaker panel is no longer hot.

Do I...

Set my multimeter to AC and volts to 1100 (next closest is 200)

Touch red to A ---- and black to C
Or
Red to B ---- and black to C

Any advice or any [ never-do-this ] type answers will be appreciated.

Danna

http://www.draftingdan.com/PICS/breaker.jpg

Do both. When the panel is hot A-C will be 120, B to C will be 120 and A to B will be 220.
Polarity of your meter (red or black) to A or (red of black to C) doesn't matter.

If this is a sub-panel, C should not be grounded to the case.

KeepItSimpleStupid...

Thank you for your reply

I think I see why the neutral bar needs replacing, is that heat damaging the large lug at the bottom?

The neutral bar needs to remain connected to the panel metal box, until there is a separate equipment grounding bar installed, bolted directly to the metal box using machine thread screws into threaded holes in the box.

Once the separate equipment ground bar is installed, THEN, remove the bonding jumper connecting the neutral bar to the metal box, AND relocate ALL the bare equipment ground wires from the neutral bar to the new ground bar.


Some cable connectors for each cable passing through the knockouts would be nice, required actually.

Whoever installed this panel should loose their license.

Perfect example of how NOT to wire a panelboard.

Damn. He's right. No ground bar. There is also no protection (bushing or strain relief) for the wires exiting the panel. Also the stripped part of the wires are to long. Sloppy.

Is this another area like here with no inspection?

Thanks for the replys...

The panel is 30 years old, no inspections around here at that time.

The white wire at location " C " goes to another panel on the exterior of the house.
It is connected there to what seems to be a grounding block. The same block also has a wire going to a rod in the ground (looks to be copper).

The exterior panel has my 100 amp main, central unit, stove, dryer, and hot water heater breakers.

If you notice at the top of the neutral bar, there was heat damage which happened approx 3 years ago.
The white wire "C" was actually cut and moved from the top to the bottom at that time.

But it seems the lug cannot be tightened as it should and it tends to move or come loose over time. Then heat builds up and causes the damage, that's what I'm being told anyway.

I guess I'll eventually have to change the entire panel.
Was hoping to get this lug secured for now, waiting for cooler weather to take on job as changing the entire panel... being in south Louisiana, cooler weather a few months away.

Welcoming any more suggestions.

Thanks
Danna

Adding New Electrical Circuits - Installing A Sub-Panel - An Overview (http://www.hammerzone.com/archives/elect/panel/sub_panel/01/overview.htm)

Seems like a good How to do. It's not obvious, but 6/3 with ground was used. Note the separate ground and neutral bars. I read elsewhere that sometimes 3 wire feeds are sometimes allowed.

Locktite 222 available here:

http://www.stanleysupplyservices.com/product-detail.aspx?pn=142-103

It's a low strength threadlocker. I've fixed many problematic loose connections on x-ray sets (10 KW), 1 KW arc lamp power supplies, electron beam power supplies (30KW). Works as designed.

Good point on using threadlocker. This stuff is also available at any local auto parts store or well equipped hardware store. Fel Pro makes similar products, though Loctite/Permatex appears to have a lock on the market...

The auto stores don't generally have the low strength stuff.

Sorry, I guess it depends on where you live. The stores in the Chicago area, at least the ones I frequent, carry the full Loctite line.