GFCI's

[Don Y]

Meter center has KWHr meter and mains input on left side (power feeds from below grade). Right side is just a "load center".

Two bus bars run the length (height) of the panel, interleaving the two "hot legs" (i.e., a double wide breaker ends up straddling both legs).

Bus bars have large "tongues" that protrude at right angles above the bars. Underside of breakers have a tight slot that grabs onto this tongue. (other "end" of breaker has a lip that clips over a metal/grounded mechanical support).

So, lift side of breaker that adheres to the tongue, pivoting on the other side that is clipped behind that metal lip. Breaker is then free to be removed -- save for any conductors that are tied to it (e.g., neutral pigtail, neutral load and hot load for GFCI; hot load for regular breaker)

Panel is at least 35 years old (so, I've been chasing down NOS spares before they become unobtanium). But, everything is still intact.

The GFCI's were purchased "new" many years ago. Note that there are 5 in the panel; three of which see everyday use (kitchen countertops plus bathrooms) and have never complained (despite large loads -- toaster oven, electric frying pan, hair dryers, etc.).

Fourth GFCI has just been "stored" in the panel. It was the candidate that I exploited to replace the GFCI for this outlet branch circuit.

I.e., too many coincidences wouold have to occur for me to conclude it was a GFCI (*breaker*) problem.

I'll look at it this weekend. I've got some candy that I've got to make, today (while SWMBO is "away")

[clare]

What GFCI breakers are you using in that "old ch" panel??

Are they listed for the panel? If it is an "old ch" panel the GFCIs were not original install - correct? or is it not that "old" a CH panel?

[clare]

On the Square D the 2 trip mechanisms are totally separate, and the GFCI load section is the same as the non GFCI breaker. No idea what breakers you have in the CH panel, but "generally" that is how they are made.

[dpb]

On 12/03/2015 3:20 PM, Don Y wrote: ...

Agreed, and all I'm suggesting doing is eliminating one possible source for that place...it could be there's a damaged area but not drastically such that it's visibly obvious that's let some moisture in and after a short time it "bakes" it out locally to the point the problem isn't apparent. But, as you've demonstrated, when it is off for any period of time, there's enough inside there to recreate the leakage path.

Now, granted, it's possible it's in one of these other locations but again, it seems silly and the _most_ time-consuming and least likely to reach nirvana quickest to start down all of the various other components looking for the case when there's still one common component that hasn't been yet eliminated. (Unless, of course, you just happen to be lucky and it's the first one you try, but that is again back to the luck of the draw, nothing you've done via "scientific method". At least I'm starting with a common cause location.

(Besides, just think how much fun you'll have when you can say "I told you so!!!!")

[Don Y]

In our case, the ground/neutral bus is located on the meter side of the panel. I.e., to gain access, you have to expose the AC mains on the output of the meter connection/input to main disconnect/output of main disconnect.

Of course, the bus bar is mounted against the rear of the panel, so you have to reach *into* the panel (with screwdriver) to open the lockdown screws in the bar. Then, reach in with your *fingers* to thread the neutral wire (or, neutral pigtail!) under the lockdown screw -- before tightening it.

So, all of the GFCI's must be located at the top of the loadcenter side of the panel -- else their pigtails won't reach the grounding bar! And, all the neutrals have to work their way up to the top of the box where they can cross over to the meter side to tie into the ground *and* neutral!

I.e., I don't like opening that side of the box! :>

You can replace a breaker just by prying the "tongue" side loose. Then, with the breaker IN YOUR HAND, you can leisurely remove the hot conductor from it! (and neutral, if a GFCI). You don't have to make any penetration into the box (and the bus bars waiting there!)

OTOH, if you opt to replace a GFCI with a non-GFCI, you now have to figure out how to get the branch circuit's neutral over to the meter side of the box!

(and, if you're only doing this to test a theory, you look for other ways to garner that information that are less involved! :> )

[Don Y]

Yes. Code requires them for kitchen countertop. etc. So, I just installed a bunch of them (bathrooms, countertops, outdoor and garage)

[Don Y]

CH GFCI's for this particular panel. Did my homework when I bought them. Hard to find cuz the panel is old -- can't just walk into a Lowe's/Home Despot and pick them up!

Took advantage of a contractor friend's discount to buy them from an (overpriced) electrical supply house, locally.

[Mark Lloyd]

[snip]

C9 lights? The 9 is the size of the bulb (I think 9mm across). IIRC power consumption is 7W.

[snip]

[Don Y]

Dunno. The "9" stuck in my mind. They are the "really big" incandescents (not to be confused with the smaller 4W and 7W (identical to the 4W in size) "night lights" you'd encounter in a house.

[I don't have any spare bulbs in store-bought packages; and the actual strings get stored in shoebox sized boxes (that aren't actually for shoes) cuz it's impractical to try to cram them back into the boxes in which they originally were purchased).]

For other incandescents, often the wattage is stamped in the metal screw base. I should see if I can read anything (that small) there...

[John G]

Many many years ago I worked as an electrician in a hospital that had an in door pool. Every day when the attendant turned on the Metal Halide HID ove rhead lights over the pool deck, the GFCI circuit breakers would trip. I c hanged the breakers and tighten the connections, but the symptoms never wen t away. When the circuit breakers were reset, the lights stayed on until t he pool closed when they were then intentionally shut off. The next day wo uld bring the same symptoms. I had surmised that perhaps the high humidity environment was causing condensation on the ballasts, but that was just a b est guess. After a while I gave up and just made it my business to turn on the pool lights every day.

John Grabowski

[gfretwell]

Since you are not paying for things you try that is not really a good analogy but without the right test equipment, eliminating things in the path is probably the only real way to go.

If I was really willing to "diagnose" this I would get a device type GFCI, Disable the trip mechanism and look at the output of the differential amplifier with a scope as I plugged in the lights, cords etc looking for the one that is the offender. You could calibrate your result using a pot and introducing a known fault value. My bet is you will see this thing cruising in the 3-4 ma range so any little glitch pushes it over.

[trader_4]

I always start on the path of trying to fully diagnose the problem instead of swapping parts. But anyone who has worked on cars has sure had many times where they wished they had the dealers stock of parts to try swapping something that is easily swappable to see if it fixes it.

Agree, that's the problem and why you're left with swapping. To conduct the required tests is going to require some advanced gear that homeowner's typically don't have. Even if I had it or had access to it, I wouldn't waste my time trying to figure it out.

[Don Y]

In addition to the expense and inconvenience, that opens up a whole can of worms. House is block so you can't move the box "an inch or two" to accommodate breakers in the new loadcenter being some different distance from where the wires come through the block.

Neighbor enhanced his service some years ago. A nightmare for him to "stretch" the wires to reach the new locations of the breakers. You roll the dice; if the wires don't reach, you're SoL (have to rerun the branch circuit).

Another neighbor had his panel catch fire (corroded mains). Same sort of issue -- can't just find "drop in" replacements for these sorts of things! (And, you're without power for the time it takes to tear down, install, rewire AND get inspected!)

"If it ain't broke, don't fix it!"

[Don Y]

"Stupid" may be a bit harsh. But, if you're not doing this sort of thing on a daily basis, it's easy to get focused on WHAT you are trying to do and forget HOW you should be doing it!!

When I was in school, I had to make some wiring changes to a friend's vehicle. Had soldering station sitting out on his vehicle (hood or trunk, I can't recall).

Realized the tip I was using was too small to convey enough heat to the work. Not keen on waiting for it to cool off...

Didn't have a rag handy to grasp it...

So, lifted my leg to use the fabric of my jeans (down by my ankle) to grab the tip and unscrew it. Then, holding the tip in my pant leg, lifted my ankle even higher to drop the (hot!) tip on the bumper. Set my leg back down -- tickled that I'd managed to do this without falling over -- and promptly picked up the tip with my right hand to place it in my *pocket*!

Of course, it never made it *to* my pocket. The sound of searing flesh was unmistakeable.

My buddy just looked at me and said, "I can't believe -- after that elaborate *dance* that you just did (to avoid touching the hot tip) -- that you just grabbed that!"

Too preoccupied with trying NOT to fall over that I'd forgotten WHY this had been necessary! :<

[Don Y]

Wouldn't explain why the other strings (alternate test load) tripped the breaker. They weren't *in* the tree.

Also wouldn't account for SWMBO's comment that *she* had had problem using the toaster oven on that circuit some months before.

"On grumbling about this ("yet another chore on my list") to SWMBO, she claims she took the toaster oven outdoors some months ago (WTF?) to "prepare" something and it wouldn't work, either."

[Don Y]

You haven't explicitly said it (and, as I suspect they are considerably ABOVE the pool, it might not be required?) but were teh HID's the load that the GFCI(s) were protecting? Or, were there other GFCI circuits and the "noise" (?) from the HID's interfering with them?

So, that's the same behavior I'm reporting? I.e., first ("cold") attempt to turn on causes breaker to trip (i.e., before it ever latches!). But, immediately thereafter, a subsequent attempt to turn on works properly?

How soon after the first failure would you reattempt? Would it seem logical that any condensate would/could evaporate in that time? (i.e., not liquid water, perhaps, but "dampness"?)

I will return to a more structure testing "program" this weekend (assuming nothing else rises to the top of the Honey-Do's). Among other things, I'd like to know if, once "holding", the crcuit will actually hold its full rated load. Or, if there is yet another set of symptoms to add to the list...

[clare]

Lots of scrounging - lots of fun.

[clare]

That's where you have to do your homework. I made sure the panel I purchased would fit. A few applications of the greenley punch - I didn't have to move a single wire - and all the wires were long enough to reach, after sorting out what went where.

If I had let the electrician supply the panel he usually uses there would have been a few junction boxes involved - and that I did NOT want!!!!

Or install a "stretcher box" - a surface mounted junction box to splice the wires. Nasty - but it works, passes code, and is not difficult.

This is where I differ. I say fix it while it is fixable - and on your schedule. Letting the panel decide when it has to be replaced never works out in your favour.

[clare]

The QO panel has a "sheilded" bus - you need to stick your finger in to touch it - I'll stick with "stupid" - or "extremely careless" - which when working around electricity IS "stupid"

[gfretwell]

When I was fixing things for a living, my first question on a support call was asking the guy who was working on it "Can you draw a circle around the problem"? (in an acre of computer room floor, that may not be as simple as it sounds)

Until you know for sure what box is failing, you really have to back up and reassess.

It was surprising how many times that just getting your head put of the box, turned a light on and got you on the right track. Isolating the problem does not mean simply throwing parts at it. You should learn something at each step.

In Don's situation,. I would start with a configuration that doesn't fail and keep adding stuff until you break it. Drag a known good space heater or heat gun out to the end of that extension cord and try that, bearing in mind, the fault could be on the neutral and that will not fail without a load.