220V dryer sparked on startup (3 wire) What to test?

[Nightcrawler®]

Oh, if you turn off the main, make sure to disable the generator, first.

[Stormin Mormon]

The power being horrendus, is worth it for view stupendous We live on a mountain Youth is our fountain And backup is our generatorendus

A tree branch takes out our power When we have wind or even a shower We go throw the transfer switch Try not to drive into the ditch And environmentalists all rally for the flower

The skyline it is all black I'm thinking of moving myself back I can't stand this condition I maintain my position We've got to buy a Generac.

[Stormin Mormon]

Have you noticed that some Usenet posters repeatedly say that they won't answer any more?

[trader4]

Sigh... It's been explained many times that the neutral and ground don't both go into the ground. You even took a pic of the 3 insulated service conductors where they enter your house. It was pointed out to you that the smaller one is the neutral. It runs back to the power transformer.

The neutral is connected together with an earth ground at your panel and at the transformer. Or as Doug says, at least they should be.....

[trader4]

Normally they run once a week to verify that they are operational, not to charge the battery. The battery is normally charged via the utility AC. Starting a generator just to charge a battery wouldn't be very efficient.

[trader4]

Keep calling me a liar, while cutting out the spot on reference I provided from the IEEE from a paper presented at an engineering conference on power. No comment on that, because it's irrefutable that their terminology and opinon on the exact question at hand is the same as mine. And at this point, it appears everyone else too, but you....

4520128

" Distribution engineers have treated the standard "singlephase" distributi on transformer connection as single phase because from the primary side of the transformer these connections are single phase and in the case of stand ard rural distribution single phase line to ground. However, with the adven t of detailed circuit modeling we are beginning to see distribution modelin g and analysis being accomplished past the transformer to the secondary. Wh ich now brings into focus the reality that standard 120/240 secondary syste ms are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/24

0 secondary is different from the two phase primary system in that the seco ndary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "

Pay special attention to the one sentence:

"Which now brings into focus the reality that standard 120/240 secondary sy stems are not single phase line to ground systems, instead they are three w ire systems with two phases and one ground wires. "

Feel free to admit at any time that you were wrong. Or keep cursing in the darkness, your choice.

[Stormin Mormon]

Anyone but me expect this thread to make the list?

[Nate Nagel]

If this is an older house there may not be a ground rod only a heavy bare copper wire connecting the ground/neutral bus of the panel to the water service entrance.

Any gas piping should also be bonded to ground, but that better not be the *only* connection...

nate

[trader4]

You see that big bare copper wire on the right side, that comes over the top and down part way on the left? It's a ground wire and it's connected right there to the neutral.

The neutrals in the house from your 120V loads carry current. The neutral leaving the house back to the Xformer carries the unbalanced current. Grounds don't normally carry current and are they for protection. If a hot wire in a grounded appliance made contact with the metal case, then current would flow in the ground wire.

Now it's a little more complicated than that, because the neutral is connected to ground at the service panel and the transformer. So, while the vast majority of the unbalanced current is going to flow back to the Xformer via the neutral because it's an excellent conductor, some small amount will flow via the earth too, because that is an alternate path. It's like having two resistors in parallel, one that's very low in ohms, one that is higher.

[trader4]

Perhaps. I just thought of another way to make krw's day. It's a little complicated and clearly over his pay grade. His position is that with split-phase service, there is only one phase present, that you can't say the two hot legs are

180 deg out of phase, etc, because it originates from only one phase of the primary distribution. Well, then what about open delta? Open delta allows a utility to provide 3 phase service for lighter loads using just TWO transformers, instead of

1. It saves the cost of an additional transformer. One transformer is connected to each of TWO primary high voltage lines. So, they have connections to only 2 primary phases, yet they deliver 3 phase power. According to krw's standards, that should be called 2 phase, because it only uses two of the transmission's 3 phases. Yet it's called 3 phase, there are 3 phases that you can see on a scope and just like the 240V/120V service it's done with transformers.

[bud--]

The top 2 breakers feed back through a conduit at the top of the service panel section. This very likely goes to the transfer switches. Two sets of wires then come back into the service panel. One exits out the top right. They are the feeders to subpanels that have backup generator power.

The transfer switch boxes each have a contactor (a large relay) that switches one feeder back and forth between normal power and generator.

Whatever is feed from the 2 top circuit breakers has backup power.

[Danny D'Amico]

I'm pretty sure the pool is not on the charger (it has three 1-3/4HP 240V pumps).

There is a man-sized blue tank which is the pressure tank with a bladder inside, and another powerful motor pressurizing the system to something like 80 psi; and, there are 10,000 gallons of water; so, it *could* be that the well isn't running on the generator, but that the pressure system is.

Thanks for pointing that out. I will check next time the power goes out.

Interesting idea. I didn't know they even existed. But, it makes sense. Even a basic automotive trickle charger would work just fine to charge the battery!

I wonder if the weekly startup also preserves the life of the motor?

It's scheduled. The generator fires itself up every Friday at the same time.

[Danny D'Amico]

East. Past where Summit road isn't Summit Road anymore.

[Danny D'Amico]

Wow. Just wow! That was clever and hilarious! And apropos all the way.

You should sell that to Generac for them to use as their theme song on the web site & in commercials!

Thanks for brightening my day!

[Stormin Mormon]

Thanks, glad my wit and poetry did some good. They are welcome to have the limerick for free. No credit needed.

[trader4]

Good luck explaining that to krw. According to him, the only proper term apparently is "opposite". What a precise engineering term...... I've even given him references to an IEEE paper delivered at a conference of power engineers that specifically addresses the point. But he just ignores it all.

[Danny D'Amico]

I am shocked! Not electrically shocked, but, mentally shocked. I was wrong about the neutral. Dead wrong. Not even close to right.

That huge bare copper ground wire looping around the circuit panel went into the exact same steel bar as all the white neutral wires of the electrical cables!

In fact, the electrical cable with both a bare copper ground wire and a white neutral wire connected to the very same "neutral/ground" bar!

I'm shocked. There's no difference, at the panel, between neutral & ground!

[Danny D'Amico]

Well, that huge bare copper wire *must* be the main ground. It does go straight down, as you can see from this picture:

But I can't tell where it goes from there. It is interesting to see all the rest of the wires go horizontally, except this ground wire, which goes straight down in the wall.

[Ralph Mowery]

That is what I have been trying to tell you.

They both go to the same place in the breaker box.

The only differance is mechanical. The neutral is usually white and the ground is either green, green with a white stripe, or not insulated. They may be differant sizes.

They do have to be marked and sized as per code to determin what wire is used for the neutral and which wire is used for the ground.

[Danny D'Amico]

This was the biggest shock to me of all!

You are totally correct! I was wrong. Dead wrong.

That big fat copper wire is connected at EXACTLY the same place as all the white neutral wires are!

For my entire life, I've thought they connected to the ground at different points. I never realized they connect to the ground at exactly the same point!

You can even see the neutral and ground wires of this cable which are both connected to the same steel strip!