What happens when electric neutral cut/disconnected?
Bill
a fully disconnected neutral with the two hots remaining connected.
So I was wondering what exactly would happen if a residential electric
service (3 wire 240/120 with neutral) lost just the electric company neutral
connection but had a good ground to the neutral bar in the main panel?
Would current flow to the ground connection?
If the load was not balanced between the two hots (only every other breaker
in use at the time [extreme situation]), could the ground wire potentially
carry say the full amperage of one of the hots?
Or in other words, should the ground wire in the main electric panel be
sized to carry the full load of one leg of the service should this situation
happen?
RBM
"Bill" <billnoma...@yahoo.com> wrote in message
news:6cijfmF...@mid.individual.net...
I don't believe I've ever seen an open neutral on a service, where the
ground was able to carry the load, although if it did carry the load, noone
would notice, and I wouldn't get involved. Typically you have lighting and
appliance imbalances, which tip off the property owner to the problem
>
Doug Miller
>I've seen "loose neutral" connections on electric service panels, but never
>a fully disconnected neutral with the two hots remaining connected.
>
>So I was wondering what exactly would happen if a residential electric
>service (3 wire 240/120 with neutral) lost just the electric company neutral
>connection but had a good ground to the neutral bar in the main panel?
Two 120V circuits turn into a single 240V series circuit, that's what happens.
This is very, very, bad, as it tends to let the magic smoke out of everything
on those circuits.
>
>Would current flow to the ground connection?
Nope.
>
>If the load was not balanced between the two hots (only every other breaker
>in use at the time [extreme situation]), could the ground wire potentially
>carry say the full amperage of one of the hots?
Not unless there's a ground fault.
>
>Or in other words, should the ground wire in the main electric panel be
>sized to carry the full load of one leg of the service should this situation
>happen?
No.
John Grabowski
The neutral conductor is the return path for the current back to the
transformer. If the transformer as well as the home had a good grounding
system and soil conditions were right, current would flow through the earth
to the transformer.
If there was not an ideal grounding system in place you could possibly have
220 volts going to circuits that shared a neutral conductor.
The electrical code does not require that your grounding electrode conductor
be the same size as your neutral conductor, which incidentally is normally
smaller than your hot conductors.
jme...@columbus.rr.com
Well any one circuit could have normal voltage or have anything
between 0 and 240 volts. I used to work for a photo studio that was
in it's second location. The first one burned up due to this little
problem. The second one also suffered from it on the first floor.
The basement (processing and finishing area where I spent most of my
time, was OK.
Under this conditions you can turn on one light and others may
become brighter or dimmer or some of each. You really don't want this
to happen.
Note. Having a good ground will not help, unless that ground is
also having problems.
S. Barker
experience some weird happenings with our lights and whole house fan. The
whole house fan is what tipped us off to the problem initially. It all of a
sudden just slowed down. Some lights were bright, some were dim. The TV
would not come on. After poking around a bit, i got out the (analog) meter
and found some outlets had about 80 volts and others had about 144. Then,
some how, i had the brilliant idea of turning on the oven. When i turned
the oven on, the fan went back to normal, the lights normal. The 240v load
apparently balanced the system. I was at somewhat of a loss at that point.
I was not near as experience in electrical things at that time. I called an
electrician friend of mine, he came down, poked around in the box some and
decided to loosen the ground on the buss. "OH! GUESS WHAT? Fire on the
ground" he said. I'm like "what's that mean"?. He said "well even though
i've never seen this before, it sure looks like an open neutral. So i get
on the horn with the power company. FYI, it was Kansas City Power and
Light. They come out, and basically look at what i'm experiencing and the
first thing the guy does is pull the meter. Then he measures the voltages
on the incoming legs. All is equal. Then he tells me the problem must be
on the inside. Puts the meter back in and the imbalance returns. "yep , he
says, problem is on your side". So at this point, i'm at wits end, not
knowing what to do, so I calls the fire dept and they say 'do you have a
fire'? I says no, but I will, if someone does not fix this power imbalance.
So that prompts a little higher level of action from KCPL, and they come out
again. The service guy makes all his checks and then talks on the radio for
a while. His supervisor says "you know that sounds like an open neutral".
The guy comes back and says they suspect an open neutral. At that point, I
explode. I said "NO SHIT SHERLOCK" I told you guys that 3 hours ago. They
ran a bare wire from my meter can to the service box on the street and lo
and behold, all becomes normal again. (did i mention i have underground
service?) They came out the next day and started digging. About a foot
from my water meter, at a depth of about 16" the neutral wire was corroded
clean in half. Apparently it had been nicked by the backhoe putting in the
water line 10 year prior. Well anyway, they fixed the wire, and all was
good for exactly a year to the day. It was so weird, one year later, HALF
the stuff in the house quit working. I had a dead leg. When they came out,
i explained what had happened the year before and so they dug again. Sure
enough, about 2 feet from the neutral problem, one of the hot legs had
corroded in half.
Well anyway, that's my long and drawn out story of an open neutral. I
forgot to mention, I took all the documents from the open neutral service
down to the KCPL office in downtown KC, Missouri and collected a check for
one TV and 2 VCRs. They were fried.
steve barker
"Bill" <billnoma...@yahoo.com> wrote in message
news:6cijfmF...@mid.individual.net...
metspitzer
>really slow. After screwing around with it, I decided the drill was
>dying and went to get another one from the back room. That room is
>dark so I flipped on the lights. They were real dim. That's when I
>realized there might be an electrical problem. I took that drill to
>the house and it worked fine. I went back to the garage and plugged
>it into another outlet. As soon as I turned it on, those dim lights
>in the back room got real bright, and a few seconds later they went
>out (they were CFL bulbs). thats when something smelled hot, and I
>found smoke around one of those CFL bulbs. I shot off the switch to
>those lights and got my test meter. I got odd votages all over the
>garage. I flipped on a light on another breaker and it flashed and
>burned out immediately. At that same time the radio in there which
>always comes on when I turn on the lights, got real loud, then quit.
>I flipped on my 240V welder and it worked fine. At the same time I
>noticed the outdoor flood light came on. With the welder on, I
>flipped on soem more lights and they all worked normally. When I shut
>off the welder some lights got real dim, others real bright.
>
If flipping stuff on causes other stuff to blow. I would quit
flipping stuff on. :)
westom
http://www.homeownershub.com/maintenance/What-happens-when-electric-neutral-cut-disconnected-315303-.htm
westom wrote:
Bill wrote:
> So I was wondering what exactly would happen if a residential electric
> service (3 wire 240/120 with neutral) lost just the electric company
> neutral connection but had a good ground to the neutral bar in the
> main panel?
Obviously an earth ground is not as conductive as a neutral wire. But it
does not have to be in most cases.
In a three wire (bi-phase) service, must current entering on one hot
wire leaves on the other. Only current that flows in a neutral is due to
imbalance in the load.
A safety ground is not as conductive as the neutral. But it should be
conductive enough so that current does not use other paths. For example,
in one house, the earth ground was completely missing. A neutral wire
broke inside the street transformer. So current took a return path via the
gas meter. When insulators finally broke down, the house exploded.
Homeowner knowledge is quite simple to avert such failures. If
incandescent bulbs change intensity when major appliance power cycle, then
get the problem eliminates. In most cases, that light intensity change is
a minor problem. In some cases, it indicates a threat to human life. At
no time should lights change intensity due to appliance power cycling.
Never ignore the symptom because in rare cases it could be a major human
safety threat such as failed neutral.
Michael Dobony
> responding to
> http://www.homeownershub.com/maintenance/What-happens-when-electric-neutral-cut-disconnected-315303-.htm
> westom wrote:
> Bill wrote:
>> So I was wondering what exactly would happen if a residential electric
>> service (3 wire 240/120 with neutral) lost just the electric company
>> neutral connection but had a good ground to the neutral bar in the
>> main panel?
> -------------------------------------
> Obviously an earth ground is not as conductive as a neutral wire. But it
> does not have to be in most cases.
>
> In a three wire (bi-phase) service, must current entering on one hot
> wire leaves on the other. Only current that flows in a neutral is due to
> imbalance in the load.
>
> A safety ground is not as conductive as the neutral. But it should be
> conductive enough so that current does not use other paths. For example,
> in one house, the earth ground was completely missing. A neutral wire
> broke inside the street transformer. So current took a return path via the
> gas meter. When insulators finally broke down, the house exploded.
How did it find that path? There has to be a connection somewhere that
should NOT be there. If the neutral is broken the current does NOT
automatically go to the earth ground unless there is an improper connection
as these are supposed to be isolated. In a stove the 240 elements will
continue to function as long as there are no controls that require 120 as
these will all be shut down. That is, a computer controlled stove will
cease to function, but an old fashioned stove with simple controls will
still cook and heat as they use only the opposing hot legs. The neutral is
only used where 120 is required.
>
> Homeowner knowledge is quite simple to avert such failures. If
> incandescent bulbs change intensity when major appliance power cycle, then
> get the problem eliminates. In most cases, that light intensity change is
> a minor problem. In some cases, it indicates a threat to human life. At
> no time should lights change intensity due to appliance power cycling.
> Never ignore the symptom because in rare cases it could be a major human
> safety threat such as failed neutral.
There is often a slight momentary dimming at the moment of startup of a
refrigerator compressor or central air compressor.
tra...@optonline.net
> On Thu, 31 Mar 2011 13:56:18 +0000, westom wrote:
> > responding to
> > westom wrote:
> > Bill wrote:
> >> So I was wondering what exactly would happen if a residential electric
> >> service (3 wire 240/120 with neutral) lost just the electric company
> >> neutral connection but had a good ground to the neutral bar in the
> >> main panel?
> > -------------------------------------
> > Obviously an earth ground is not as conductive as a neutral wire. But it
> > does not have to be in most cases.
>
> > In a three wire (bi-phase) service, must current entering on one hot
> > wire leaves on the other. Only current that flows in a neutral is due to
> > imbalance in the load.
>
> > A safety ground is not as conductive as the neutral. But it should be
> > conductive enough so that current does not use other paths. For example,
> > in one house, the earth ground was completely missing. A neutral wire
> > broke inside the street transformer. So current took a return path via the
> > gas meter. When insulators finally broke down, the house exploded.
>
> How did it find that path? There has to be a connection somewhere that
> should NOT be there. If the neutral is broken the current does NOT
> automatically go to the earth ground unless there is an improper connection
> as these are supposed to be isolated.
I would guess that what he means is that:
A - there was no proper earth ground to the panel and
B - the gas meter was bonded to the ground system of the house which
is connected to the neutral at the main panel.
> In a stove the 240 elements will
> continue to function as long as there are no controls that require 120 as
> these will all be shut down. That is, a computer controlled stove will
> cease to function, but an old fashioned stove with simple controls will
> still cook and heat as they use only the opposing hot legs. The neutral is
> only used where 120 is required.
>
>
>
> > Homeowner knowledge is quite simple to avert such failures. If
> > incandescent bulbs change intensity when major appliance power cycle, then
> > get the problem eliminates. In most cases, that light intensity change is
> > a minor problem. In some cases, it indicates a threat to human life. At
> > no time should lights change intensity due to appliance power cycling.
> > Never ignore the symptom because in rare cases it could be a major human
> > safety threat such as failed neutral.
>
> There is often a slight momentary dimming at the moment of startup of a
> refrigerator compressor or central air compressor.- Hide quoted text -
>
Exactly what I was thinking too. I've seen new construction in $1 mil
homes
where a similar motor load will cause lights to dim momentarily at the
end of
long runs. For example, turning on a shop vac. I've seen that
happen in
many homes. If the standard was no noticeable
change in intensity ever, you'd probably need to rewire most of the
homes
in the US.
N8N
ITYM "lights on a different circuit than the appliance." I can't
remember living anywhere where a light on the same circuit as a
microwave for instance wouldn't dim even on a 12AWG, 20A ckt.
nate
N8N
> > responding to
Neutral and earth are bonded together @ main panel. So they are not
isolated.
nate
jamesgangnc
>
> - Show quoted text -
But the earth rod and the transformer ground are not going to carry
enough current to stabilize the load. Loss of neutral between the
house and the service will result in the potential between the two
hots and neutral varying depending on the total load on each side. So
it will be divided just like it is now but not always equally. And
this will affect just about everything in the house as even many 240v
appliances use 120 for some things.
westom
http://www.homeownershub.com/maintenance/What-happens-when-electric-neutral-cut-disconnected-315303-.htm
westom wrote:
> But the earth rod and the transformer ground are not going to carry
> enough current to stabilize the load. Loss of neutral between the
> house and the service will result in the potential between the two
> hots and neutral varying depending on the total load on each side.
Variation is minimized so that neutral currents do not use other paths
(ie water heater, furnace) to obtain earth via gas pipes. So that higher
voltages do not exist and did not compromise gas line gaskets.
Among many functions of earth ground is to reduce voltages due to a
neutral failure. Had that homeowner reacted properly when lights were
changing intensity (when 120 volt appliances were power cycling). Or had
that homeowner inspected his earth grounds, then his house would not have
exploded.
N8N
> enough current to stabilize the load. Loss of neutral between the
> house and the service will result in the potential between the two
> hots and neutral varying depending on the total load on each side. So
> it will be divided just like it is now but not always equally. And
> this will affect just about everything in the house as even many 240v
> appliances use 120 for some things.
True. (although I've never seen a "transformer ground" - are houses
now getting four wire service entrances?) My point was, though, that
they are bonded together, so if the ground connection is completely
lost, that unbalanced neutral current will try to find any path it can
to ground, which will likely be either a water or gas line (or both)
nate
jamesgangnc
>
> - Show quoted text -
Transformers are usually grounded. Houses still have 3 wires. 2 hots
and a grounded neutral.
Larry W
westom <westom1_at_g...@foo.com> wrote:
>
> Among many functions of earth ground is to reduce voltages due to a
>neutral failure. Had that homeowner reacted properly when lights were
>changing intensity (when 120 volt appliances were power cycling). Or had
>that homeowner inspected his earth grounds, then his house would not have
>exploded.
>
>
And exactly where was this home that exploded anyway?
--
The best argument against democracy is a five-minute conversation
with the average voter. (Winston Churchill)
Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org
cl...@snyder.on.ca
The REAL indicator of a failed/failing neutral is lights that "flare"
when a load cuts in, because the heavy load (frdge starting, etc)
causes a low resistance on the one leg, causing voltage to go up on
the other leg.
bud--
> responding to
> http://www.homeownershub.com/maintenance/What-happens-when-electric-neutral-cut-disconnected-315303-.htm
> westom wrote:
Typical response from homeownershub to a thread that is almost 3 years old.
> jamesgangnc wrote:
>> But the earth rod and the transformer ground are not going to carry
>> enough current to stabilize the load. Loss of neutral between the
>> house and the service will result in the potential between the two
>> hots and neutral varying depending on the total load on each side.
> -------------------------------------
>
> Variation is minimized so that neutral currents do not use other paths
> (ie water heater, furnace) to obtain earth via gas pipes. So that higher
> voltages do not exist and did not compromise gas line gaskets.
>
> Among many functions of earth ground is to reduce voltages due to a
> neutral failure.
Cite a source that agrees It is not an intended function of earthing
because it is not reliable.
As usual from homeownershub, this question was answered almost 3 years ago.
Among the answers - from gfretwell:
"Back in the olden days when all the homes were connected together by a
solid metal piping system, nothing would happen. Now days you would
end up with an unbalanced service. One side of the panel would have
high voltage and the other would be proportionately low. Dirt is a
terrible conductor and your ground rod is pretty useless as a neutral."
*If* you have a typical metal municipal water supply system the neutral
current can run to adjacent houses and back through their neutrals,
using the N-G bonds at all the houses.
(Unfortunately that wouldn't work for westom because he says that a
metal water pipe can't be used as an earthing electrode.)
There is probably about a post a year here of bright/dim lamps caused by
a bad service neutral.
--
bud--
N8N
> and a grounded neutral.
Which we usually refer to as "neutral" and absolutely DOES carry
enough current to stabilize the load... that's its intended
function. I'm confused at what you are trying to say?
nate
jamesgangnc
>
> - Show quoted text -
I was replying to the poster that said he had never seen a transformer
ground and asked if houses have 4 wires now. Did I say the service
entrance neutral did not carry a load? No, I didn't.
N8N
I was that poster, and yes you did.
"But the earth rod and the transformer ground are not going to carry
enough current to stabilize the load. "
then you said, in response to my post
"Transformers are usually grounded. Houses still have 3 wires. 2
hots and a grounded neutral."
I didn't start off to bust your balls, but now I feel obligated to
because at this point I haven't a clue whether you know what you're
talking about or not.
In short, if you are using "transformer ground" and "neutral"
interchangeably, then you did make an incorrect statement.
nate
bud--
> On Apr 1, 1:31 pm, jamesgangnc<jamesgan...@gmail.com> wrote:
>> On Apr 1, 1:27 pm, N8N<njna...@hotmail.com> wrote:
>>
>>
>>>>>> But the earth rod and the transformer ground are not going to carry
>>>>>> enough current to stabilize the load. Loss of neutral between the
>>>>>> house and the service will result in the potential between the two
>>>>>> hots and neutral varying depending on the total load on each side. So
>>>>>> it will be divided just like it is now but not always equally. And
>>>>>> this will affect just about everything in the house as even many 240v
>>>>>> appliances use 120 for some things.
>>
>>>>> True. (although I've never seen a "transformer ground" - are houses
>>>>> now getting four wire service entrances?) My point was, though, that
>>>>> they are bonded together, so if the ground connection is completely
>>>>> lost, that unbalanced neutral current will try to find any path it can
>>>>> to ground, which will likely be either a water or gas line (or both)
>>
>>>>> nate
>>
>>>> Transformers are usually grounded. Houses still have 3 wires. 2 hots
>>>> and a grounded neutral.
Seems to me this is fine but would "a neutral that is grounded" work better?
>>
>>> Which we usually refer to as "neutral" and absolutely DOES carry
>>> enough current to stabilize the load... that's its intended
>>> function. I'm confused at what you are trying to say?
>>
>>> nate- Hide quoted text -
>>
>>> - Show quoted text -
>>
>> I was replying to the poster that said he had never seen a transformer
>> ground and asked if houses have 4 wires now. Did I say the service
>> entrance neutral did not carry a load? No, I didn't.
>
> I was that poster, and yes you did.
>
> "But the earth rod and the transformer ground are not going to carry
> enough current to stabilize the load. "
>
> then you said, in response to my post
>
> "Transformers are usually grounded. Houses still have 3 wires. 2
> hots and a grounded neutral."
>
> I didn't start off to bust your balls, but now I feel obligated to
> because at this point I haven't a clue whether you know what you're
> talking about or not.
>
> In short, if you are using "transformer ground" and "neutral"
> interchangeably, then you did make an incorrect statement.
>
> nate
I thought james was clear and correct.
--
bud--
jamesgangnc
I didn't. I made 2 statements. In response to your 2 sentences.
First you said you had not seen transformer grounds. Then later you
asked if houses had 3 or 4 wire service.
1. Yes, transformers are usually grounded.
2. Houses have 3 service wires.
I didn't say there was a relationship between those 2 statements. I
didn't say anything about the grounds being able to carry the load. I
didn't comment on what happens if the neutral service line is broken.
You're reading a lot of things into two simple statements. All I did
was tell you that transformers are typically grounded and that houses
have 3 service wires. Quit trying to read things into a post that are
not there. I didn't try to say anything else. You've jumped to half
a dozen other assumptions from my simple comments. If I'd wanted to
say something else I would have said it.
N8N
Still not seeing how your initial statement was correct. You stated
that the xformer ground would not carry the unbalanced neutral
current. Isn't that exactly what it is designed to do? I'm not aware
that it is common practice to provide a neutral in transmission lines,
only distribution ones.
nate
cl...@snyder.on.ca
wrote:
Not what I heard him say - but even what I heard didn't make a whole
lot of sense.
cl...@snyder.on.ca
wrote:
>On Apr 1, 2:04 pm, jamesgangnc <jamesgan...@gmail.com> wrote:
It's my understanding the distribution, usually 3 phase, feeds 3
transformers - but be that true or not, each transformer gets 2 power
wires to the primary, and the center tapped secondary has 3 wires, L1,
N, and L2.
Inmany areas it is common practice to run one bare and 2 oinsulated
wires from transformer to service stack when using overhead wire. The
bare wire is sometimes a steel cable and it supports the other 2
(live) wires, and is grounded at the pole and at the service panel.
This is obviously not the only way to do it, but it is fairly common.
Look at inspectopedia.com/electric/Electrical_Ground_Required.htm for
all you ever wanted to know about grounding, bonding, and neutral
conductors.
The Daring Dufas
The "bare" is probably ACSR cable. Aluminum Conductor- Steel Reinforced.
The center strand or strands will be steel for strength and the outer
strands are the aluminum conductor. You may actually see the strands
separated with the steel wire/s attached to a support and the aluminum
strands crimped to an entrance cable neutral.
http://www.sural.com/products/bare/acsr.htm
TDD
Robert Green
<stuff snipped>
<ITYM "lights on a different circuit than the appliance." I can't
remember living anywhere where a light on the same circuit as a
microwave for instance wouldn't dim even on a 12AWG, 20A ckt.>
Thanks for pointing that out. When I added new circuits to the kitchen, I
was sorely disappointed that light on that circuit still dimmed when the
microwave started up. I thought something must be wrong somewhere but
rechecking everything to the point of overloading the circuit with two space
heaters to see if it indeed carried 20A and popped at 25A and it did, so I
forgot about it. Nice to know that it's just what happens. I suppose when
the microwave starts dimming lights on unrelated circuits that you have to
worry . . .
--
Bobby G.
jamesgangnc
Now you're arguing about my earlier post. If you cut the neutral
coming into your entrance panel and leave the house ground rod(s)
connected, the ground rod(s) will not handle the load originally
carried by the neutral. Ground resistance is too high. Go pound a
ground rod into your yard somewhere and measure the current when you
connect a hot to it.
barry....@gmail.com
> I've seen "loose neutral" connections on electric service panels, but never
> a fully disconnected neutral with the two hots remaining connected.
> So I was wondering what exactly would happen if a residential electric
> service (3 wire 240/120 with neutral) lost just the electric company neutral
> connection but had a good ground to the neutral bar in the main panel?
>
>
> If the load was not balanced between the two hots (only every other breaker
> in use at the time [extreme situation]), could the ground wire potentially
> carry say the full amperage of one of the hots?
>
> Or in other words, should the ground wire in the main electric panel be
> sized to carry the full load of one leg of the service should this situation
> happen?
barry....@gmail.com
House ground was the copper water service pipe. Current must have been finding its way back to the transformer via the ground, but I advised the owner to call the utility company and get it fixed right away.
bob.h...@c2hae.com
> I've seen "loose neutral" connections on electric service panels, but never
> a fully disconnected neutral with the two hots remaining connected.
>
> So I was wondering what exactly would happen if a residential electric
> service (3 wire 240/120 with neutral) lost just the electric company neutral
> connection but had a good ground to the neutral bar in the main panel?
>
> Would current flow to the ground connection?
>
> If the load was not balanced between the two hots (only every other breaker
> in use at the time [extreme situation]), could the ground wire potentially
> carry say the full amperage of one of the hots?
>
> Or in other words, should the ground wire in the main electric panel be
> sized to carry the full load of one leg of the service should this situation
> happen?
When I arrived, I had them reenergize the system and it ,no joke, sounded just like about 15, 10 hp motors single phasing !! All the GFCI recepts were smoking , and two caught fire before I could shut the main off!, The Neutral had been cut underground between the pad mounted xfmr and the service entrance !This of course put 240 volts across in series with the 120 volt recepts , and a direct load across the GFCI recepts of the time! That is when and I am the reason they changed to and MOV activated GFCI! The Leviton rep gave me 10 cases of GFCI to keep quiet. but it did not work !!THey did reimburse me , but never gave me the labor money back!
bob.h...@c2hae.com
ALl residential power supplies are 3 wire to the entrance, if , you loose the neutral, there is no path for the grounded conductor , except thru the ground electrode conductor to , what usually is a high resistance connection , which is a problem itself! Unless you have a 3 wire system and a copper water line bounded to the grounded conductor, then it would still act the same way!
rclark....@gmail.com
> I've seen "loose neutral" connections on electric service panels, but never
> a fully disconnected neutral with the two hots remaining connected.
>
> So I was wondering what exactly would happen if a residential electric
> service (3 wire 240/120 with neutral) lost just the electric company neutral
> connection but had a good ground to the neutral bar in the main panel?
>
> Would current flow to the ground connection?
>
> If the load was not balanced between the two hots (only every other breaker
> in use at the time [extreme situation]), could the ground wire potentially
> carry say the full amperage of one of the hots?
>
> Or in other words, should the ground wire in the main electric panel be
> sized to carry the full load of one leg of the service should this situation
> happen?
jeffgr...@gmail.com
mille...@gmail.com
michaelo...@gmail.com
The bond screw in a mains switch or breaker panel connects neutral to ground. The screw is removed in panels of multi unit dwellings, even if they are individually metered.only one connection between neutral and ground per service, according to ontario electrical code.
In a multi-meter building, if the neutral has failed between the meterbase and the panel, all kinds of funky shit can happen.120v devices will perform weirdly if at all.
However,
- if it is the service neutral
- or the neutral between a single gang meterbase and a main panel/switch,
- and the ground is low impedence (a good ground)
The user may experience absolutely no difference in performance because the bond screw carries the unbalanced load to earth. The is no requirement that the electrons travel back to the transformer.
We had an ice storm. Lost my neutral for a week. No problem. Single service meterbase.
hadley...@gmail.com
forev...@gmail.com
After that, I noticed my floor fan and ceiling fans ran slower than usual. Some incandescent lights were also much dimmer than. Other lights on other circuits were fine. My central air seemed to be running fine too. After about an hour, the lights and fans all started working normal again. I did a visual check of my panel and nothing appeared or smelled bad.
Could the "loose neutral" be causing the problem? I'm concerned there's a serious electrical problem that may cause more problems later. I called Southern California Edison and was told that I needed to be currently experiencing problem for Edison to send crews out to check.
My next step is to check my panel for any loose or burned wiring.
Jesse C.
That's very common with direct burial. I know, I've dug a lot of holes and
busted a lot of concrete in my day making splices.
--
for full context, visit http://www.homeownershub.com/maintenance/what-happens-when-electric-neutral-cut-disconnected-315303-.htm
hassan...@gmail.com
> "Bill" <billnoma...@yahoo.com> wrote in message
> news:6cijfmF...@mid.individual.net...
> > never a fully disconnected neutral with the two hots remaining connected.
> >
> > So I was wondering what exactly would happen if a residential electric
> > service (3 wire 240/120 with neutral) lost just the electric company
> > neutral connection but had a good ground to the neutral bar in the main
> > panel?
> >
> > Would current flow to the ground connection?
> >
> > If the load was not balanced between the two hots (only every other
> > breaker in use at the time [extreme situation]), could the ground wire
> > potentially carry say the full amperage of one of the hots?
> >
> > Or in other words, should the ground wire in the main electric panel be
> > sized to carry the full load of one leg of the service should this
> > situation happen?
>
>
> transformer. If the transformer as well as the home had a good grounding
> system and soil conditions were right, current would flow through the earth
> to the transformer.
>
> If there was not an ideal grounding system in place you could possibly have
> 220 volts going to circuits that shared a neutral conductor.
>
> The electrical code does not require that your grounding electrode conductor
> be the same size as your neutral conductor, which incidentally is normally
> smaller than your hot conductors.
Dear John,
You referred to an Electric Code that doesn't require the Ground conductor to be the same as Neutral. Can you please mention the specific Code # you are referring to?
BR
Hassan
TE W
The neutral on my Daughter's house was cut by AT&T. That burned every wall
socket that was in use in the house and burned off the driven ground. It may
not be noticeable at first but as the ground rode caroades from cathodic
effect. BE CAREFUL
--
for full context, visit https://www.homeownershub.com/maintenance/what-happens-when-electric-neutral-cut-disconnected-315303-.htm
Unknown
All are bogus 100% practical skilled is when neutral is cut from the load then
the black wire will be variated as phase current.
josephro...@gmail.com
mart...@gmail.com
> I've seen "loose neutral" connections on electric service panels, but never
> a fully disconnected neutral with the two hots remaining connected.
>
> So I was wondering what exactly would happen if a residential electric
> service (3 wire 240/120 with neutral) lost just the electric company neutral
> connection but had a good ground to the neutral bar in the main panel?
>
> Would current flow to the ground connection?
>
> If the load was not balanced between the two hots (only every other breaker
> in use at the time [extreme situation]), could the ground wire potentially
> carry say the full amperage of one of the hots?
>
> Or in other words, should the ground wire in the main electric panel be
> sized to carry the full load of one leg of the service should this situation
> happen?
http://www.abc.net.au/news/2018-03-05/what-causes-taps-to-be-electrified/9508664
So be careful and get an electrician to check it out.
edwinr...@gmail.com
Smitty
Transformer grounds sole purpose is to ground the can should it become
engerized. It is to protect anyone servicing the equipment. However the X2
bushing that the neutral uses running to the house is bonded internally to the
transformer case also. You could technically use just the neutral wire as your
ground for the transformer too but it's just added protection. Because the two
are technically connected, yes it would help carry your unbalanced load, but
your transformer ground should still be connected to the same pole ground and
main line neutral as the service neutral so it does help, but not that is not
the transformer grounds purpose.
Smitty
I could be wrong but most of not all service neutrals are all alluminum. No
steel strand, because they usually are only pulled hand right depending on the
length of the span. They attached to the service spool or eyebolts usually
with preforms or wrapped back to themselves with a crimped connection. Same at
the house mast or house knob to a preform or some other form of attachment,
and is connected with an H block connector to the service neutral from the
meter box
lakeho...@gmail.com
Jim Murphy
To my knowledge, the house service is fed three wire, two hots one neutral. In
the meter panel, the ground connection and the neutral from the street end up
getting tied together in the meter socket. Any inbalance in the load returns
to the source, in this case, the transformer hung at the pole or wherever. So
if you lose the neutral, you may or may not even notice it depending on where
the neutral is open, and if you have a decent ground or not but yes, houses
have burnt because of this especially when things like a refridgerator get 240
volts instead of 120. Code up here is two 8 foot ground rods driven 6 feet
apart. This ground goes into the meter box and ends up tying on the same
grounding block as the street neutral.
Min
Excellent description of your event. My brother had the same problem with his
house. Since, current was going through the grounding electrode the basement
bathtub faucet was live.and can gave you a little shock. I found the green
colour corroded ground (neutral) termination next to the overhead service
mast. After one polite phone call to Toronto hydro as a home owner they came
over with a crane to fix the problem. Just remember to be polite and
reasonably technical if you are not an electrician when calling the utility as
they can easily send you to a third party for investigation.
billstoc...@gmail.com
Christopher
> I can answer this with experience. A long long time ago, (about 1987) we
> experience some weird happenings with our lights and whole house fan. The
> whole house fan is what tipped us off to the problem initially. It all of a
> sudden just slowed down. Some lights were bright, some were dim. The TV
> would not come on. After poking around a bit, i got out the (analog) meter
> and found some outlets had about 80 volts and others had about 144. Then,
> some how, i had the brilliant idea of turning on the oven. When i turned
> the oven on, the fan went back to normal, the lights normal. The 240v load
> apparently balanced the system. I was at somewhat of a loss at that point.
> I was not near as experience in electrical things at that time. I called an
> electrician friend of mine, he came down, poked around in the box some and
> decided to loosen the ground on the buss. "OH! GUESS WHAT? Fire on the
> ground" he said. I'm like "what's that mean"?. He said "well even though
> i've never seen this before, it sure looks like an open neutral. So i get
> on the horn with the power company. FYI, it was Kansas City Power and
> Light. They come out, and basically look at what i'm experiencing and the
> first thing the guy does is pull the meter. Then he measures the voltages
> on the incoming legs. All is equal. Then he tells me the problem must be
> on the inside. Puts the meter back in and the imbalance returns. "yep , he
> says, problem is on your side". So at this point, i'm at wits end, not
> knowing what to do, so I calls the fire dept and they say 'do you have a
> fire'? I says no, but I will, if someone does not fix this power imbalance.
> So that prompts a little higher level of action from KCPL, and they come out
> again. The service guy makes all his checks and then talks on the radio for
> a while. His supervisor says "you know that sounds like an open neutral".
> The guy comes back and says they suspect an open neutral. At that point, I
> explode. I said "NO SHIT SHERLOCK" I told you guys that 3 hours ago. They
> ran a bare wire from my meter can to the service box on the street and lo
> and behold, all becomes normal again. (did i mention i have underground
> service?) They came out the next day and started digging. About a foot
> from my water meter, at a depth of about 16" the neutral wire was corroded
> clean in half. Apparently it had been nicked by the backhoe putting in the
> water line 10 year prior. Well anyway, they fixed the wire, and all was
> good for exactly a year to the day. It was so weird, one year later, HALF
> the stuff in the house quit working. I had a dead leg. When they came out,
> i explained what had happened the year before and so they dug again. Sure
> enough, about 2 feet from the neutral problem, one of the hot legs had
> corroded in half.
> Well anyway, that's my long and drawn out story of an open neutral. I
> forgot to mention, I took all the documents from the open neutral service
> down to the KCPL office in downtown KC, Missouri and collected a check for
> one TV and 2 VCRs. They were fried.
> steve barker
> > never a fully disconnected neutral with the two hots remaining connected.
> >
> > So I was wondering what exactly would happen if a residential electric
> > service (3 wire 240/120 with neutral) lost just the electric company
> > neutral connection but had a good ground to the neutral bar in the main
> > panel?
> >
> > Would current flow to the ground connection?
> >
> > If the load was not balanced between the two hots (only every other
> > breaker in use at the time [extreme situation]), could the ground wire
> > potentially carry say the full amperage of one of the hots?
> >
> > Or in other words, should the ground wire in the main electric panel be
> > sized to carry the full load of one leg of the service should this
> > situation happen?
> >
> >
cody schwegel
> On Thu, 31 Mar 2011 13:56:18 +0000, westom wrote:
> > responding to
> > westom wrote:
> >> So I was wondering what exactly would happen if a residential electric
> >> service (3 wire 240/120 with neutral) lost just the electric company
> >> neutral connection but had a good ground to the neutral bar in the
> >> main panel?
> > Obviously an earth ground is not as conductive as a neutral wire. But it
> > does not have to be in most cases.
> >
> > In a three wire (bi-phase) service, must current entering on one hot
> > wire leaves on the other. Only current that flows in a neutral is due to
> > imbalance in the load.
> >
> > A safety ground is not as conductive as the neutral. But it should be
> > conductive enough so that current does not use other paths. For example,
> > in one house, the earth ground was completely missing. A neutral wire
> > broke inside the street transformer. So current took a return path via the
> > gas meter. When insulators finally broke down, the house exploded.
> How did it find that path? There has to be a connection somewhere that
> should NOT be there. If the neutral is broken the current does NOT
> automatically go to the earth ground unless there is an improper connection
> as these are supposed to be isolated. In a stove the 240 elements will
> continue to function as long as there are no controls that require 120 as
> these will all be shut down. That is, a computer controlled stove will
> cease to function, but an old fashioned stove with simple controls will
> still cook and heat as they use only the opposing hot legs. The neutral is
> only used where 120 is required.
> >
> > incandescent bulbs change intensity when major appliance power cycle, then
> > get the problem eliminates. In most cases, that light intensity change is
> > a minor problem. In some cases, it indicates a threat to human life. At
> > no time should lights change intensity due to appliance power cycling.
> > Never ignore the symptom because in rare cases it could be a major human
> > safety threat such as failed neutral.
> There is often a slight momentary dimming at the moment of startup of a
> refrigerator compressor or central air compressor.
Actually, The ground is bonded to the neutral in one location on all services (typically we see this at the meter base). This means if the incoming neutral is lost, then current automatically goes to ground. A poor ground will cause all of the problems you mention, but if your ground resistance is less than 25 Ohms, you may never see a problem.