The wife said the dryer was sparking "in the back".
I moved things around, but didn't see anything so I tell the wife not to worry.
A week later, I turn on the 220v 3-wire dryer, and a single bright white spark
snaps in the back, between the dryer and the 4-foot 6-inch diameter aluminum
corrugated lint pipe connect to the outside vent.
Could it be static electricity?
Could it be the dryer frame is hot?
What do I test?
The only connection to the wall is the three-pronged 220v dryer cord, which
looks perfectly fine when I remove it from the wall outlet.
There is no specific "ground" wire from the dryer to anything (should I have
put a ground wire in to the 120 volt outlet nearby?).
What would you test?
If you need pictures, just ask.
My gut sense, is that something is loose inside
the dryer. Something (sounds like) is touching
the case of the dryer, and charging it.
I'd pull the plug, check for continuity between
power and ground prongs of the plug. I'd also
open up the case, and look for bare, burnt,
or loose wires.
Do you have any friends with electrical skills?
It could be static electricity. Is the 4 foot long vent pipe seperated from
the dryer by some material that does not conduct electricity ? If so you
may want to connect a wire between the pipe and dryer. It does not have to
be very large as almost no curent is going through it, just high voltage.
You may also want to look at the dryer where the power wire is. As this is
only a 3 wire cord make sure there is a strapgoing from the neutral wire to
the frame of the dryer. This should be factory installed so it can be used
for 3 wires or bent out of the way if a 4 wire cable is used.
While it may not trip a breaker, I would think it might if there was an
intermittant short in the power wiring.
What is your multi-meter doing? How about measuring things between vent
pipe and dryer body for a starter? 220V can kill.....
Tony,,, You can only get the one leg of voltage to ground on a 220 volt
system on a dryer. However that also is dangerous. The OP may have a sagging
heater coil that is touching the case. If he is not handy on this stuff,
time to get an appliance repairman to check and repair it. WW
That's interesting. I never saw a heater coil, let alone a sagging
Googling for images, I see these:
I'll have to look deeper...
On Thu, 14 Nov 2013 15:55:24 -0500, Stormin Mormon wrote:
This is the 3-pronged 220 volt cord connected to this dryer:
I think, IIRC, two of the prongs are 120 volt hot wires, 120 degrees
out of phase (that's the 220 volts); while the third, I think, is a
So, I think, IIRC, the 120V circuitry in the dryer (e.g., the light
bulb and the controls and perhaps even the motor) run off one of
the hot wires and the neutral; while the heater runs off the full
220 volts from the two hot wires and the neutral.
So, there is no ground that I know of, if I understood this correctly.
That's why I asked if you guys ADD a ground wire in this situation?
No, you misunderstood (or the reference you looked at was wrong; I
didn't check it) -- the third wire is the ground but NEC until
relatively recently allowed the ground to also be the neutral in
specific instances, the household dryer likely the most prevalent
followed closely by electric range.
The "blinding flash" _may_ have been one of the two heater coils failing
-- does the dryer still reach full temp and otherwise function properly
as far as you can tell? If it's now taking a lot longer for things to
dry, likely you did lose an element.
If, as somebody else noted, it didn't trip the breaker the likelihood of
a short other than the element is minute. In 60 yrs in a dry climate
I've never seen a static electricity flash from a dryer vent or even got
a shock so don't say it's not possible but surely sounds far-fetched
hypothesis to me.
OTOH, when wife sewed a lot or when were many cloth diapers so that
straight or safety pins accidentally getting in the dryer caused fair
number of element shorts when one would finally manage to get thru the
vent holes in the rear of the drum and land across a heater coil. Or,
they do eventually fail on their own...
You seem to understand this better than I do.
The way *I* understand a "ground" is that a ground wire carries no current
(unless there is a problem). The "neutral" wire, on the other hand, *always*
That's a pretty big difference (as I understand it anyway).
More specifically, the way I understand a ground wire, is that it goes
from the receptacle in the wall to the main breaker panel, where it
literally is driven directly into the ground (usually by some kind of bar).
In contrast, the neutral wire, as I understand it, goes to the same
breaker panel, but then it goes from there to the power pole, and then
from that pole it may travel hundreds of feet to a few more power poles,
but eventually, it too is driven straight into the ground.
The difference, as I understand it, is that the ground never carries
current (unless there is a fault), while the neutral is always carrying
current (and therefore it might have a potential on it).
Given that they're not at all the same thing, I then have trouble
understanding the statement that the ground is "also" a neutral.
Again, you seem to understand better than I do, but, the way I
described it above, a ground and a neutral are totally different
So, I don't understand how a ground can 'also' be a neutral.
The power comes into your house by 3 wires. At the pole is a transformer
that has a wire on each end of a coil and one from the center. If you only
used 240 volt devices there would be no need for the neutral wire. If the
power usage on each side of the 120 volt lines were exectally the same there
would not be any need for the neutral going to the pole. As the sides are
not exectally ballanced and often not ballanced very well at all, the
neutral carries the unballanced current. In the house the 120 volt circuits
use one of the hot wires and the neutral for the return.
At your breaker box the neutral is bolted to the frame of the box and it
also goes to the recepticls and other parts of the house. The ground wire
goes to a rod outside the house that is driven into the ground. It is
bolted to the frame of the breaker box. It then also goes whever the power
wires goes to such as the recepticals. In effect the neutral and ground
wire are the same wire, but perform differant functions. Often the neutral
or ground wire may be a differant size than the two hot 240 volt wires. If
the neutral and ground wires are the same size, there is no electrical
reason that you could not use either of them for the ground or neutral. YOu
do not want to do this as it can create great confusion to the people doing
the wiring. That is one reason the neutral is insulated and white and the
ground is either bare or green.
The two hot wires may be red and black or maybe just two black wires as it
does not usually mater which wire is hooked to which side of the 240 volt
YOu are correct, there should not be any current on the ground wire unless
there is a problem. If one of the hot wires shorts to the frame of the
dryer and there is no ground or neutral (on a 3 wire plug) connected to the
frame, it becomes 120 volts to ground and if you or anything conductive gets
between the frame and the real ground or another device that has its frame
grounded, there will be current flowing and could shock or kill.
If in the 3 wire circuit the neutral becomes disconnected down line of the
dryer, the frame of the dryer will become hot with 120 volts minus a small
ammount. That small ammount could be the timmer and light bulb in the dryer
that is still connected to one side of the 240 volt line.
That is the reason for using the 4th wire that is only connected to the
frame of the dryer in later years.
On Thursday, November 14, 2013 8:55:14 PM UTC-5, Danny D'Amico wrote:
That is true. But I have to be careful here. You said that the
neutral *always* carries current. I know what you mean, but there
are some here who insist on all cases being covered. So, to be
correct, it should be said the neutral carries the unbalanced
portion of the load in that 240V circuit. Whew. I hope DD
feels better now. The ground doesn't carry current unless something
It's tied to the ground system of the house at the panel.
It is for 3 wire appliances that were permitted to be installed
that way prior to the 90s when the code was changed. They use one
conductor for both the ground and the neutral.
As far as I know, the dryer works just fine.
My wife said it was making static sounds in the back, when she turned it on
about a week ago, which I had dismissed until I saw the bright spark at the
aluminum vent hose when I turned it on.
The spark happened quickly, so, I'm not exactly sure *where* it was, but, it
was *OUTSIDE* the dryer.
The white spark *appeared* to be between the dryer frame and the
aluminum vent hose, as shown in this picture in a RED mark:
This is good to know, since the static electricity idea was the only
one I could come up with that was benign.
I would agree that static electricity isn't likely, so, let's forget
But, if it's not something benign, then I need to figure out WHAT is
making that spark, and why.
The whole fact that there is no explicit ground is part of what confuses
I'll check to see if the body of the dryer is hot with respect to ground.
On Thu, 14 Nov 2013 21:40:25 -0500, Stormin Mormon wrote:
I may well be out of my league, but, I've wired 220 in
the past, and, well, *I* used two black and one white
(i.e., two hots and a neutral), and it worked, for me.
My problem at that time was that the wiring was in an
old house with screw-in fuses, so, that arrangement
above would tend to blow one fuse but not the other,
which wasn't really a good idea.
I could tell a fuse had blown 'cuz the motor would
hum instead of move for the compressor. But, when I
replaced the fuse, it would work again.
Dumb. Yes. I agree. Darwin award even? Perhaps.
But, clearly, *my* 220 in that case was two hots and
I supposed had I two hots and a ground wire tied to
the cold water pipe, it would have worked as well.
And, I must note, that I've *followed* the neutral
wire, in the olden days, when wires were above ground,
from the house, to the pole, to the next pole, to the
next (as far as I could tell anyway), until it went
straight into the ground.
Of course, I really didn't follow the wire directly,
but, I surmised the neutral went into the ground at
every third pole. At least that's what I remember
surmising way back when ...
So, *both* a ground and a neutral go into the ground.
The only difference, as I see it, is that the neutral
goes into the ground hundreds of feet away, and it
carries current; while the ground goes into the ground
at the edge of the house, and, it's not carrying current
(unless there is a fault).
So, given all that, I think we're talking semantics here.
I have two hots and this "thing" which goes into the
ground a few hundred yards from the house.
Apparently this "thing" is acting both as a ground, and
as a neutral. I'm going to check that this "thing" is
actually *connected* to the steel case of the dryer and
On Fri, 15 Nov 2013 22:14:25 +0000, Danny D. wrote:
By the way, the reason (I think) I know that this 'thing'
is a neutral (and not a ground) is that it *must* be
If the two hots were out of phase by 180 degrees, then
we wouldn't need this third 'thing'.
But, three wire distribution along the poles is such that
the hot wires are only 120 degrees out of phase (IIRC).
So, if I'm correct, my two hots are 120 degrees out of phase,
which means current *must* be going somewhere. That somewhere
is this third 'thing'.
Since this third 'thing' is designed to carry current, it's
clearly not a ground (since a ground isn't designed to carry
Now, again, the fact that this third 'thing' goes into the
ground makes it 'look' like a ground (to some); but it *must*
be carrying current; so, semantically, I wouldn't call it a
Still - I must profess ... this is only how *I* understand the
situation; and I may well be wrong (although I think it's this way).
So, I will try to explain what you guys are trying to tell me
in the next post (this is too long already).
On Fri, 15 Nov 2013 22:21:18 +0000, Danny D. wrote:
I think you guys are trying to tell me that this third 'thing'
goes from the wall to the dryer innards.
At the same time, it goes to the dryer steel frame!
So, if one of the hot wires were to touch the steel frame,
it would go into this third 'thing' and it would go back to
And, from the wall, it would go to the breaker box; and from
the breaker box to the power pole; and from the power pole
to another, and finally, a pole or three away, it would go
into the ground.
Back at the dryer, that would mean that the steel case of
the dryer is attached to the ground by a long wire of a
few hundred feet or more.
So, the steel case *could* have a potential on it!
(which would be the difference in voltage between the hot
wire and the ground a few hundred feet away).
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