- Location
- Massachusetts
Well you are mistaken, besides it being required by code it is safer to bond the water lines then not.
Bonding/Grounding copper water lines
- Thread starter rcmoon
- Start date
- Status
Well you are mistaken, besides it being required by code it is safer to bond the water lines then not.
- Location
- Illinois
- Occupation
- retired electrician
And I would think that this is extremely rare .... not even convinced it happened they way you said it did.
How do you know the neutral was energized?
Did you measure voltage at the time and if so between what points.
Exactly what type of damage did you have?
So which would you think has a better chance of happening; 1) My case, which was the service drop hot wire insulation deteriorated or was rubbed off by a tree branch causing it to contact the bare neutral/ground wire that it was wrapped around thus energizing all my neutral and ground conductors in my house as well as my water line that the service ground is tied too or 2) A circuit in my house decided to disconnect itself from a device or outlet and craw under the house and touch my copper pipes under the slab? Note: my water heater is piped with CPVC.
I didn't want to write a book on what happened but seems I need too since some don't get it; I was in my house and all of a sudden I heard a lot of popping and smelt and saw smoke coming from some surge protectors, I immediately went out side and tripped my main 200 amp breaker. I checked voltage coming in and found I had 220v between line side neutral and one hot leg and 220v between both hot line legs. I checked the service drop wire myself and found what happened, which is what I've posted many times in this thread. Just in case you think I'm an idiot, the power company confirmed it and cut out the section and replaced it. The voltage on my neutral damaged a lot of appliances and TV's, etc.
I'm not hear to convince people what happened, I'm certain of what happened. I just wanted some opinions on whether its safer not to tie the water pipe to the ground from the service since in my case it could have killed someone if they were taking a shower or washing hands, etc. I think theres a great chance and probably very common for number 1 above to occur and no chance of number 2 occurring.
macmikeman
Senior Member
- Location
- Planet macmikeman
So much of Florida water supply is sent thru pvc water lines. That's a problem in itself for multiple reasons, but the best one I can think of is the backup path to the poco transformer on loss of neutral thru another customers neutral which also is connected thru his water pipe grounding to his neutral at his service is absent due to pvc water piping. Maybe we could have the ''smart meters'' supervise for phase loss and neutral loss as part of the bargain for having an electronic meter stuck to the side of the house instead of the good old analog kind that wasn't prone to catching fire.
You had an open neutral to start with or what you said happened could not have happened. If the neutral was solidly connected to it's source and came in contact with an ungrounded conductor from the same source you would have had a short circuit and would most likely have heard a boom.
BTW, if you actually read 220V on a residential service you may have other problems.
Roger
BTW, if you actually read 220V on a residential service you may have other problems.
Roger
- Location
- Illinois
- Occupation
- retired electrician
I have no doubt that you can have damage that would result in a grounded to ungrounded fault on the service drop....I have extreme doubts that the fault energized the neutral....your description is exactly what happens when the service neutral opens.
That being said, it is always safer to have everything bonded...the more you have bonded the smaller the chance of touching two items that are at a different potential...even if you have an elevated voltage on something it is safer that you have that elevated voltage on everything...no potential between the things that are bonded together.
jminer99er
Member
- Location
- Sacramento, CA
Had the same thing happen 3 weeks ago. #10 out of the weather head was drapped over the #2 triplex messenger, it welded on to the neutral, 240 neutral to B phase. It burned up a gate controller that caught fire, along with surge arrestors. A QO2 panel lug pretty much melted off the plastic. All this was fed from a 1ph 25kva pole mount xfrm 12kv pri 120/240 1700ft away, never blew the cutouts.
(Trying to figure image uploads)
(Trying to figure image uploads)
Attachments
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Really unwise installation. Either by the electrician or the POCO tech who made the connection.
You got that right.
Still isn't a good enough reason to leave pipes unbonded like the op suggested. Should we do away with bonding completely because of a few instances like this ?:happyno:
Forget water pipes: anything in the house that was bonded would have been a risk in that regard.
Last edited:
- Location
- Illinois
- Occupation
- retired electrician
I still don't understand how that can energize the neutral with line voltage. It is a direct short via the neural back to the transformer. There is no way that type of fault should be able to energize a connected neutral.
electricguy61
Senior Member
The OP is mistaken, "bless his heart"
. What he thinks happened is not what actually happened, no matter what the POCO says {In Scotty's best voice: "You Can't Change the Laws of Physics"}. If you've been in the electrical service trade for any length of time, you've seen what happens when the POCO neutral fails, probably multiple times.
To not bond metal water lines is simply suicidal.
. What he thinks happened is not what actually happened, no matter what the POCO says {In Scotty's best voice: "You Can't Change the Laws of Physics"}. If you've been in the electrical service trade for any length of time, you've seen what happens when the POCO neutral fails, probably multiple times. To not bond metal water lines is simply suicidal.
Exactly same thing that happened to me, except in my case it was the main service conductors from the service drop, which were probably #1 AL. If an ungrounded conductor comes in contact with the neutral (bare) conductor from a service drop and your properly grounded per NEC at the service to ground rods and water pipe, its 100% that your copper water pipes will be energized.
- Location
- Massachusetts
No, that is dead short.
Now if just your neutral opens that can result in all bonded objects at the house being live compared to the dirt around the house.
electricguy61
Senior Member
Yes, your water line may become energized, for as long as it takes the POCO fuse to blow. But the blow out of your electronics was caused by high voltage from a lost neutral.
But no doubt your years in the trade have given you more knowledge then the folks trying to answer your question here. My regrets to your family if you un-bond your water lines.
jminer99er
Member
- Location
- Sacramento, CA
Not enough incident energy to blow cutouts? More then likely not sized correctly. I was curious at what length in wire would it have to be to just look like a load?
- Location
- Illinois
- Occupation
- retired electrician
The utility primary fuses are not sized to protect the transformer or the transformer secondary conductors. They are only sized to prevent a fault on the load side of the cutout from taking out the distribution circuit.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If the neutral was neither open nor compromised, then until an OCPD intervenes the water pipe could be energized to as much as half of the line to ground voltage of the faulted wire. More if a reduced size service neutral was used. It will not be raised to the full open circuit line potential.
The condition will normally not last very long though.
- Location
- Illinois
- Occupation
- retired electrician
Correct, but that will not increase the line to neutral nor the line to line voltages, in fact, both of those voltages will be below normal.. In addition, everything connected to the electrical grounding system will be at this elevated voltage. In the case of a fault on the line side of the service OCPD, normally the fault burns clear, but that could take some time.If the neutral was neither open nor compromised, then until an OCPD intervenes the water pipe could be energized to as much as half of the line to ground voltage of the faulted wire. More if a reduced size service neutral was used. It will not be raised to the full open circuit line potential.
The condition will normally not last very long though.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
It seems to me that if L1 shorts to N, moving N and EGC in the direction of the L1 voltage, it would necessarily raise the L2 to N voltage.
I do not yet understand your argument that the L2 to neutral voltage will decrease. Unless you are assuming that both the L1and L2 voltage from the transformer will decrease because of a short on L1 only.
- Status