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

[krw]

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?

[krw]

The person that took, what fifteen years, to finally learn to not top post? The one who constantly adds off-topic nonsense to threads? You think anyone is going to listen to your net-copping? You're deluded Mormon.

[Danny D'Amico]

I was always told that base 60 allowed the Babylonians to divide by the most numbers (1,2,3,4,5,6).

As I understand it, the Babylonians created the 360 degree circle by starting from pie sections.

BASE 16 didn't work for them: a) If you split a pie in half (vertically), you get 2 parts. b) If you split that in half (horizontally), you get 4 parts. c) If you split that yet again in half (with an "X") you get 8 parts. d) If you keep doing that, you get 16 parts e) This goes on depending on when you want to stop.

16 is dividable by 1,2,&4.

But, if you split into 12 parts instead of 16, you can now divide by more things, i.e., you can divide 12 by 1,2,3,4,&6.

If you keep dividing, your 12 becomes 60, and now you can divide by 1,2,3,4,5,&6 (and a few more).

So, the clock, I'm told, became 12 hours and 60 minutes.

How that 60 minutes multiplied by 6 to 360 degrees, I'm told, is just a matter of having better granularity.

So, if I understand what I really didn't understand, base 60 was merely more dividable by things than any other base the Babylonians could come up with.

But, I could be wrong because they came up with the Metric system for a reason ...

[krw]

Idiot. I've responded *MANY* times. You keep saying *exactly* the same thing in different ways and expect a different, wrong, answer. Sorry, but you may have nothing else to do in your life but argue, I'm done playing your game. If you haven't been able to read what I've written by now, I'm not wasting any more time on you.

As an engineer, you certainly suck.

[Danny D'Amico]

Very nice. Thank you. You're hope that the USENET is still alive & well! I'm printing it, and will leave it with the dryer and refer to it when I debug!

[krw]

You're wrong and can't read.

[Danny D'Amico]

Thanks for confirming that. It was wired professionally (Costco delivery team), and I never touched it since (except to plug it into the wall).

[krw]

Swap any two wires and the motor will rotate in the opposite direction. An induction motor (the most common type) won't rotate in lock-step, anyway. It will slip (rotate slightly slower) when loaded.

Yes! Someone who gets it! Please explain it to the dummy, Trader.

Precisely correct.

[Danny D'Amico]

:)

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.

[krw]

OMG! I thought it was only the US that used a non-French system!

Pi sections? No, it was because 12 (hours), 60(minutes), and

360(degrees) are such a beautiful numbers. They have so many factors.

Where did that come from?

Yep. It's a beautiful number.

Sure, but Pi had nothing to do with it.

A good reason but like anything French, it's certainly not perfect.

[krw]

All it tells me is that it's a neutral (it does carry current). That it's smaller and insulated sounds normal to me.

[Tony Hwang]

Hi, In summary between L1 and L2(240V) there is no phase to talk about. Between L1 and CT, L2 and CT(2 x 120V ) there is phase to talk about. If it were single phase one, this two legs will have alternating output. I had to dig out my old school text book. And I had to drag out my Tek. dual trace scope in a LONG time. Nothing to difficult to understand, really!

[krw]

Be careful. You might make a lot of smoke. ...if you're lucky.

...and 240V between them.

They're the opposite. That's the only way there could be 120V from each to ground and 240V between them. If there were less, they couldn't be opposite. There can't be more.

Imagine a circle of radius 120 units. From the center to any point on the circle it's 120 units. From one side of the circle to a point directly opposite is 240 units. Between any other two points it's something less than 120 units (never more).

[trader4]

Then the IEEE, the most respected electrical engineering organization in the country, must suck too, because here's a paper from the IEEE that specifically addresses the exact issue:

4520128

"Distribution engineers have treated the standard "singlephase" distributio n transformer connection as single phase because from the primary side of t he transformer these connections are single phase and in the case of standa rd rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Whi ch now brings into focus the reality that standard 120/240 secondary system s are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secon dary phases are separated by 180 degrees instead of three phases separated by 120 degrees. What all of this means is that analysis software and method s must now deal with an electrical system requiring a different set of algo rithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap tran sformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary."

Here's the essential point that says I'm right and you're wrong. I've seperated it out for you, since you clearly have a learning problem:

"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."

That's from a paper published by the peer reviewed IEEE and delivered at a conference of power engineers. Read it and try to learn something instead of hurling insults.

[trader4]

Yes. If you graph each hot vs the neutral, you will have two 120V sine waves that differ 180 deg in phase.

[trader4]

Sigh. Some engineer. Engineers talk in terms of the phase relationship of waveforms. KRW only understands "opposite"

And more obfuscation thrown in for good measure.

You could listen to KRW. Or you can listen to the IEEE (Institute of Electrical and Electronic Engineers) Here's a paper from the IEEE that specifically addresses the exact issue:

4520128

"Distribution engineers have treated the standard "singlephase" distributio n transformer connection as single phase because from the primary side of t he transformer these connections are single phase and in the case of standa rd rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Whi ch now brings into focus the reality that standard 120/240 secondary system s are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secon dary phases are separated by 180 degrees instead of three phases separated by 120 degrees. What all of this means is that analysis software and method s must now deal with an electrical system requiring a different set of algo rithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap tran sformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary."

From the above, here's the essential, irrefutable point:

"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."

That's from a paper published by the peer reviewed IEEE and delivered at a conference of power engineers, not from the flapping gums of KRW.

[Nightcrawler®]

The two wires are the same phase and that each in reference to the neutral show 180 degrees out of cycle. Both are on the same phase.

[Nightcrawler®]

Maybe he likes hairy bush. You know, when they get all slippery and wet, it is much easier to grab a handful and yank them back towards you. :-)

[Nightcrawler®]

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.

[Nightcrawler®]

No.