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

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On Fri, 15 Nov 2013 23:40:45 -0600, Nightcrawler® wrote:

I do not know the answer to that question, but, I do know that all the hot wires on the distribution power poles are supposedly bare.
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You can't go outside and look at it? It is rather obvious.
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On Sat, 16 Nov 2013 16:16:25 -0600, Nightcrawler® wrote:

Here is a picture taken just for you:
http://farm3.staticflickr.com/2886/10915925156_0e21cf1404_o.gif
I wish I actually understood what you're trying to ascertain so that I could give you the answer you seek to help you explain it to me.
What I can *see* are three huge aluminum wires going into the circuit panel at the outside wall of the house (my power wires come from underground, which is the code around here).
All three are insulated; one, the smaller-gauge wire, is striped (presumably that's the neutral which, I believe, is tied to ground somewhere a few hundred yards away, and which theoretically carries the current back to the power company to complete their power loop).
What does the insulation on all three incoming cables tell you?
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On Mon, 18 Nov 2013 00:48:09 +0000 (UTC), Danny D'Amico

The neutral only carries the difference of the current in the other two wires - the reason it can be smaller.

That all three conductors are insulated?
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On Sun, 17 Nov 2013 21:13:46 -0500, krw wrote:

:)
Well, I was asking because I was told to see if the wires were insulated, so, now that I know they're insulated, I was trying to figure out why I was asked to find that out.
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On Mon, 18 Nov 2013 02:24:31 +0000 (UTC), Danny D'Amico

All it tells me is that it's a neutral (it does carry current). That it's smaller and insulated sounds normal to me.
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The main thing I was trying to figure out was what type of service entry that you had. I errantly thought that you had overhead, but I am glad that you clarified things.
All three wires go to the same location. There are terminations underground that you cannot see, and if you wanted to pop open an underground box cover you will see some termination points via direct burial connectors. Though, I am certain the utility provider has the lid locked or uses special 5 sided bolt(s) to secure the lid. The point, off in the distance, probably goes to the same box that feeds your house. As an aside, is there a metal (copper clad) rod sticking out of the ground underneath, or there about, your meter- main? If so, is there a wire coming off it (bare or green)?
Anyway, the picture that you show is obviously the feed, and the wire with the stripe is the "neutral", but as is evident there is not a ground connection in this section of the enclosure. The two bus bars going to the right go straight to the upper meter "stabs". Prongs that the meter slides into. There are four. The lower stabs feed the residence.
The "neutral" continues up into a raceway, before going to the right, via another bus bar, and comes down along side the meter, probably on the right side. There should be a lug at the end of this bus and this is where your ground bond will be done. Ground rods/ufer and metal water pipe (if present) within 10ft of said pipe's entry into the residence is what will be utilized to facilitate this process. It is possible that the ground rods might be inside the footprint of the building, underneath the structure. Not knowing how the place is built only has me speculating.
Hmmm, one thing I did not ask is whether or not you are the only customer on this feed. If so, there might not be an underground box, and the wires go straight to the transformer, and might do so even if you are not. Different places run their utilities in their own way. Regardless, the thingy you see off in the distance, which is grounded, is for the transformer center tap, and does not feed your service. That line will come straight off of the transformer.
Alright, I am done with this, for now.
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On Mon, 18 Nov 2013 10:40:18 -0600, Nightcrawler® wrote:

I'd *love* to know all of this information!
For example, given this is the service entrance, can anyone tell if my neutral is connected to ground at the house or if it's *not* connected to a ground at the house?
http://farm4.staticflickr.com/3780/10932993223_cb9139da3c_o.gif
Here's a closeup of the connections to the ground/neutral of the house:
http://farm6.staticflickr.com/5473/10932861244_a29b4ea518_o.gif
If anyone can explain how the neutral in the picture is different (or the same) as the ground, that would be enlightening to me (and others)!
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The National Electrical Code requires that it be connected to ground within some specific (and short) distance from where it enters the house. Whether it actually *is* so connected or not is a different matter. It certainly *should* be.

That big bare copper wire that loops up over the top of the service panel and back down the right side is your grounding conductor. Follow that, and see what it's attached to.
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On Monday, November 18, 2013 4:34:10 PM UTC-5, Danny D'Amico wrote:

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.
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I thought that myself, at first. I am still uncertain if this observation is correct. You will notice that the bare wire is split-bolted to two other wires on the right side of the panel. The color on my monitor is messed up and I was not able to determine the color of the wires (insulated) that are connected to the bare copper wire. If not green, or if there is not a ring of green tape wrapped around each of the insulated wires, something was done wrong.
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Checking the new angle, it would appear that you are correct. The first shot I looked at sort of hid that, or my monitor is getting so bad that I not only need reading glasses, but a new monitor, too. Probably both.
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On Tue, 19 Nov 2013 21:30:58 -0600, Nightcrawler® wrote:

I don't see any green tape, so, I'll look closer tomorrow in the daylight.
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Don't worry about it. My monitor is on its last legs and some things just don't show up right, nor clear. Sometimes it does not turn on at all. It is old, and I want to relocate where I do my computer work and get something mondo!
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On Tue, 19 Nov 2013 02:59:57 +0000, Doug Miller wrote:

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!
http://farm6.staticflickr.com/5535/10951789823_ffc7975152_o.gif
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!
http://farm4.staticflickr.com/3785/10951551955_219c18389a_o.gif
I'm shocked. There's no difference, at the panel, between neutral & ground!
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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.
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On Tue, 19 Nov 2013 15:03:26 -0800, snipped-for-privacy@optonline.net wrote:

OK. I understood what you *said*, I really did. But, what I *thought* I understood was that every third power pole (or so), there was a ground wire that went straight into the ground.
I've *seen* this wire with my own eyes (I'll have to go look for some power poles to snap a picture).
I always *thought* that bare wire was the neutral from the transformer (which you said isn't a neutral but I'm saying how I *thought* it was) going into the ground - so that it would complete the circuit to the power company (theoretically).
I *did* read all the posts about what happens between the breaker box and the transformer - but - that part still eludes me. It's my fault though - since it has been explained so, I'll just work on that separately.
Right now, I'm still working on the panel itself, which is a shocker to my pre-conceived (wrong) notions.
Shheesh. All these years, I've been treating them differently, when they're all connected to the exact same damn spot!
I couldn't been killed! :)
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On Tuesday, November 19, 2013 6:12:14 PM UTC-5, Danny D'Amico wrote:

That's right, the neutral is grounded periodically, which is what I said.

The utility neutral is grounded just like the neutral in your house is grounded. Just like you call the wire from your panel to the ground rod, water pipe, whatever the "ground", not the neutral, you call the wire grounding the utility neutral a ground wire.

No, you won't be killed if you treat them differently. They are different. Treating them the *same* is what can get you killed.
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On Wed, 20 Nov 2013 05:46:53 -0800, snipped-for-privacy@optonline.net wrote:

I just realized that the power pole, which has only three wires on it, must be adding the fourth to the ground only at the transformers.
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On Tue, 19 Nov 2013 15:06:23 -0800, snipped-for-privacy@optonline.net wrote:

I will read that. Thank you.
BTW, what's with the *red* wire here?
http://farm6.staticflickr.com/5540/10951792723_46b5882ec1_o.gif
How is it any different than the black wires?
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