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

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On Tue, 19 Nov 2013 18:47:36 -0500, Stormin Mormon wrote:

That's interesting. It must be the case, because that "romex?" cable has four wires in it. (1) a bare ground, (2) a white neutral, (3) a black power, and (4) a red wire, which, if it's a 220V cable, would then be the second power.
It makes sense that the red is merely the second 220V hot leg, as the only other red I've ever seen is a sometimes-hot switched 120V wire to a lamp or three-way switch.
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It was hard to tell from your pix but it looks like the red and black wire go to a 240 volt breaker. One goes to one of the hot wires and the other goes to the other so you have 240 volts across them, the white is the neutal an the bare is the ground.
The red is the same as the black but colored differantly so you know which is which.
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On Tue, 19 Nov 2013 19:31:49 -0500, Ralph Mowery wrote:

You are correct. I followed the romex? from the hole in the wall to the circuit breaker, and, that white romex appears to feed the 240V outlet in the garage that you can see on the right side in this picture:
http://farm4.staticflickr.com/3816/10933073015_e0c5ff74c3_o.gif
The funny thing is that there are *four* wires in that Romex? cable, but, we already determined this style of socket only has *three* connections.
Working backward, that romex? appears to come up the bottom right rectangular hole in the panel as shown here:
http://farm4.staticflickr.com/3785/10951551955_219c18389a_o.gif
And, then, it seems to connect to the 30A 220V breaker at the bottom left, top breaker:
http://farm4.staticflickr.com/3713/10951553445_08698c037a_o.gif
I'm not sure *why* we would want to know which leg is black and which leg is red but I have nothing against identifying which is which.
The only thing I don't understand is where the fourth wire goes in that Romex? cable because we already ascertained there are only two hots and a "grounded neutral" in the outlet on the wall.
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It makes things easier to troubleshoot if things go wrong, and there are certain applications where it is necessary to have specific color codes. It is preferential, especially in commercial/industrial work, to have everything color coded denoting phase/neutral/ground by color and by labeling of each conductor as to which panel they originate from and to which circuit breaker they are attached to or associated with.
Example: There are five panels labeled PNL 1, PNL 2...PNL 5. Two panels have conduits that intersect in a 16x16x4 screw cover junction box. To simplify what wires are what (let us say PNL 2 and PNL 4 have 3 wires each entering, among many others). There is a black a white and a green from PNL 2, with the hot coming from circuit breaker 6. The black and white wires would be labeled PNL2 6, or PNL2 CB6. Space on PNL2 6 is intentional. The green may be labeled only PNL2. Now, the wires from panel 4 consist of three wires that are Blue, White and Green. As you may suspect, the blue and white wires will be labeled PNL4 CB#. And the green will be PNL4. The color is done to let you know what phase and type of voltage and/or to distinguish each conductor from the other. The labeling gives source location and termination point. It just makes things easier when you have to go back in and start messing with things. It is not allowed to use the wrong color of wire for a specific voltage source.
You should not see a blue wire in the power distribution of a residential system. It happens and no one really gives a rip, but on principal this is not supposed to happen. Black, red, white and green are what you should see. Poly-phase systems are another discussion. That is where you will see blue, brown, orange, yellow and purple. There are more colors, but that is still another discussion.
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On Tue, 19 Nov 2013 21:56:18 -0600, Nightcrawler® wrote:

OK. I'm happy to know that the red is another hot for the 240V lines.
Thanks for clarifying that. Right now I'm more worried about the brown scorching... :)
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On Tue, 19 Nov 2013 21:56:18 -0600, Nightcrawler® wrote:

I noticed the aforementioned diagram shows a red and black coming out of the transformer:
http://farm8.staticflickr.com/7292/10955976554_054ba18de1_o.png
Interestingly, I see a ground on both sides of the transformer.
I wonder which ground it was that I remember seeing going down every third power pole?
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This is done to keep good continuity between the earth grounds. They perform a resistance check of the soil and determine the proper spacing of grounding electrodes to keep the potential equalized, and also to ground the neutral wire (if present) strung along with the power lines to eliminate transient/induced voltages. How many of these poles have transformers on them or other utility devices?
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On Tue, 19 Nov 2013 22:35:27 -0600, Nightcrawler® wrote:

That makes sense. I was going off of memory with "every third pole". I remember, as a kid, wondering what 'all those wires' were. Over time, I learned:
a) The three high wires were the three phases of power distribution. b) The low thick cables were the telephone (and then later, cable). c) The house only got two wires (now I know it's from the xformer). d) The transformers got two of the hot wires (I had thought). e) The ground was the return back to the power company (figuratively). f) Every third pole had a ground to ensure the power company got it.
From the aforementioned diagram, I'm realizing "d" above is wrong:
http://farm8.staticflickr.com/7292/10955976554_054ba18de1_o.png
Do I interpret the diagram correctly, that, of the three hot distribution lines on the power poles (each 120 degrees out of phase with the other), the transformer does NOT get two of those, but, it gets only one hot out of the three on the pole?
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Danny D'Amico wrote:

Hi, Yes, it is. You get 220V between red and black. 120V between neutral and either red or black.
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On Tue, 19 Nov 2013 16:47:13 -0800, Oren wrote:

I wasn't sure how they connect to the bars underneath. So, this panel seems to mainly feed three other panels with 100A service: 1. Pool 2. Rec room 3. Laundry room
Of the four baby breakers, two are 240V but only one is in use; while the other two are 120V but again, only one is in use. a. Garage 240V & well 240V b. Unintelligible 120V
I wonder what 120V circuit is so important that it has its own puny 30A breaker as the only 120V breaker in the entire circuit panel?
Does it feed the generator electronics perhaps? (PS: I can test it in the morning.)
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The breaker is sized to protect the conductor attached to it. In this case a 10 gauge or larger wire. The wire is sized to provide the proper ampacity to the device being powered. If you are powering a 25 amp device you would feed that device with a 30 amp breaker as long as the device does not have an inrush current that would trip the breaker. That is an entirely different discussion. In essence, motors draw much more current on start up than when running. This is a factor in selecting proper wiring/ protective methods.

Nobody here knows.
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On Tue, 19 Nov 2013 01:13:33 -0600, Nightcrawler® wrote:

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.
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If scheduled it is as trader4 stated. It is a maintenance cycle. Some stand alone units have their own A/C charger that switches off of utility when the generator is running. It all depends on how many bells and whistles are included with the package.
Generac is a reputable back-up power provider, and I would not think that they would not provide such a provision. Though, some people look at cost over functionality...until it is too late.
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On Tue, 19 Nov 2013 20:33:09 -0600, Nightcrawler® wrote:

Actually, I've had to replace the battery, so, I had to read the manual, and I'm positive it runs exactly one week after I hit the switch.
So, I'm positive it's a 7-day thing, to the hour.
It runs for 20 minutes, to the minute.
So, at least *this* generac is dumb.
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On Tuesday, November 19, 2013 10:27:09 PM UTC-5, Danny D'Amico wrote:

That it runs once a week is not a sign of the generator being dumb. I still bet that it runs once a week as a self-diagnostic, not to charge the battery. For one thing, how would it know that 20 mins is the correct amount of time to charge it? It's also kind of inefficient to take current out of a battery, just to charge it, when you don't have to.
Nightcrawler raised the issue that some cheaper generators might not keep the battery charged off of the utility AC. That may be true, but I've seen typical home Generacs and they do keep the battery charged off utility AC. They also have a charging circuit that charges the battery when the generator is running. But the once a week cycle is to exercise the generator, keep the brushes from oxidizing, verify that it runs OK, and if it doesn't it sets a code, an alarm, etc so that you know the gen is kaput before you need it.
What yours exactly does, none of us here know.
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On Wed, 20 Nov 2013 06:04:17 -0800, snipped-for-privacy@optonline.net wrote:

TO lay this one to rest, I snapped a picture of the placard on the generator next to the control panel:
http://farm3.staticflickr.com/2880/10989722255_a6d40085a1_o.gif
SET EXERCISE TIME INSTRUCTIONS Place Manual/Auto Off switch to "Off" position. Place and hold "Set Exercise Time" switch to "On" postion for 5 seconds. Wait 30 Seconds. Place Manual/Auto/Off switch to the "auto" position. Failure to wait 30 sec. may cause engine to start. If engine does start, it will shut off automatically within 2 min. Generator will now exercise every 7 days, at set time.
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On Tue, 19 Nov 2013 05:15:22 -0800, snipped-for-privacy@optonline.net wrote:

I was wrong, and I apologize.
I was shocked when I saw the white neutral wires, and the green ground wires, and the bare copper ground wires, all going to the exact same spot in the main circuit breaker box!
http://farm8.staticflickr.com/7392/10951790763_d01bc0a34e_o.gif
So, green/white/bare, are all the same connection, at the breaker.
This is so counter-intuitive, to me, that it took a while for it to sink in. I apologize for being thick headed. I just never would have thought all three are connected at the same spot!
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On Tuesday, November 19, 2013 5:31:08 PM UTC-5, Danny D'Amico wrote:

Realize that even though they are connected together, there is a difference. Current if flowing through the neutral wires on your 120V circuits, throught the neutral bar, and through the neutral to the transformer. Even though the ground wires are tied to the neutral, there should be no current flowing in the ground wires of the house circuit, unless something is malfunctioning. And there will be a little bit of current flowing from the neutral/ground connection to your grounding electrode, but most of the neutral current is flowing back to the transformer on the neutral service cable.
So, while they are connected together, the current flow is from white/neutrals to other white neutrals on the other hot leg/phase, or on the neutral cable back to the transformer.
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On Tue, 19 Nov 2013 14:48:21 -0800, snipped-for-privacy@optonline.net wrote:

Actually, I think I'm pretty clear on the "functional" difference, and, on the mechanical difference with respect to insulation and colors.
That's actually why I had a problem with them all connecting together. Sheesh. They're all "grounding" wires!

Yes. I can see the neutral bar is directly attached to the inch-wide neutral strap which, itself, is the center tap of the dedicated transformer for my house.

Yes. I do understand that. The ground wire doesn't "complete" a circuit, unless something is wrong.

I think I understand that also. The current 'wants' to flow back to the transformer over that big fat insulated striped aluminum wire; but some will flow down the much thinner bare copper wire to that grounding electrode driven into the ground.
http://farm6.staticflickr.com/5490/10953633174_68d624356b_o.gif
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On Tue, 19 Nov 2013 16:27:49 -0800, Oren wrote:

I wonder if the rusted screw is related to the burnt insulation on that wire that you pointed out to me?
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