gas hot water heater jump or not

[Natfuelbilll]

Since we are still asking questions at this point...

Given a washbasin or tub with water, a hair dryer or curling iron, and a cord cap inserted into a receptacle, and of slip of the hand.

Why not bond the metallic drain pipes? This would assist in tripping of the short circuit device.

Could lives have been saved?

 

[don_resqcapt19]

Why not bond the metallic drain pipes?

The bonding of the drain pipes is required by 250.104(B) if the piping is "likely to become energized". It is my opinion that drain piping is not likely to become energized.
Don

 

[jwelectric]

The bonding of the drain pipes is required by 250.104(B) if the piping is "likely to become energized". It is my opinion that drain piping is not likely to become energized.
Don

Is a metal waste water pipe is still a metal water pipe is it not?
If it is a water pipe then would it not fall under 240.104(A)?
If it is not what makes it not?
Is the only thing that causes a pipe to fall under the provisions of 250.104(A) being that the pipe has to have water in it at all times?
Would the trap of a metal waste water pipe cause this pipe to conform to the requirements of 250.104(A)?

 

[Natfuelbilll]

I am likely to become satisfied when "likely to become energized" is somehow officially defined.

I am also likely to become poorer by paying my taxes and also very likely to become saved once I meet my maker.

If I was the one with the hair dryer (I stopped using a curling iron years ago) thatt was dropped in the sink, then I would say, "yup, that is likely to become energized".


When did this "likely to become energized" phrase come into print? To me, it stinks of legal wrangling.

 

[don_resqcapt19]

Mike,

Is a metal waste water pipe is still a metal water pipe is it not?

As this is not defined in the NEC you would have to use the common defintions. In this case I would defer to a plumber, but I really doubt that a plumber would call the waste piping system an water piping system.
Don

 

[don_resqcapt19]

When did this "likely to become energized" phrase come into print? To me, it stinks of legal wrangling.

It appeared in the last few code cycles replacing the words "may become energized". CMP 5 says both sets of words mean the same, but I do not agree.
Don

 

[iwire]

Given a washbasin or tub with water, a hair dryer or curling iron, and a cord cap inserted into a receptacle, and of slip of the hand.

Why not bond the metallic drain pipes? This would assist in tripping of the short circuit device.

I highly doubt that a bonded drain pipe would aid the tripping of an OCPD in your scenario.

I would be willing to bet that you could drop a live hair dryer into a bonded stainless steel sink full of water and the hair dryer would continue to run pumping water instead of air. The branch circuit OCPD would not open.

On the other hand a GFCI would likely trip.

 

[Natfuelbilll]

I highly doubt that a bonded drain pipe would aid the tripping of an OCPD in your scenario.

I would be willing to bet that you could drop a live hair dryer into a bonded stainless steel sink full of water and the hair dryer would continue to run pumping water instead of air. The branch circuit OCPD would not open.

On the other hand a GFCI would likely trip.

I agree about the GFCI tripping. But how come the branch circuit OCPD would not trip? Any expereince?

 

[iwire]

But how come the branch circuit OCPD would not trip?

At 120 volts to ground I do not believe that the high resistance of tap water will pass enough current to trip the breaker.

Any expereince?

Sort of, when I was about six years old I almost electrocuted one of my sisters.

I had seen an above ground pool with its filter, so I figured my wading pool needed one.

I placed my 120 volt erector set motor in the pool and plugged it in, I stayed outside the pool.

It ran fine, the problem began when my sister who was in her teens placed a foot in the pool and got blasted.

Thankfully she was fine but I can tell you my rear was sore for a while after Dad got home.

More recently I saw 9 120 volt evaporator fans in a supermarket seafood case running submerged in water working like propellers on a boat.

 

[iwire]

i thought you did not have to jump gas hotwater heaters , hot and cold pipes only electric water heaters, is it in nec to jump gas water heaters or not to ground pipes.

You will not find anything in the NEC that specifically requires a jumper at the water heater.

What is required is that the water piping systems are bonded to the services grounded conductor.

That can be accomplished many ways besides a jumper at the WH.

 

[George Stolz]

Is a metal waste water pipe is still a metal water pipe is it not?
If it is a water pipe then would it not fall under 240.104(A)?
If it is not what makes it not?

In the 1975 text that you posted, it was clear that sewer piping was not included, thanks to the more specific FPN that was present at that time. The FPN made it clear that they were not addressing sewer pipes.

Now that the FPN is more ambiguous, it's less clear. They should either be more specific with their FPN or more specific with their code text, I would prefer the latter.

I would say given the historical exclusion of the sewer pipe, and the lack of text specifically asking for a sewer pipe to be included in 250.104(A), then the AHJ should be inclined to continue to exclude it.

 

[jwelectric]

I have to jump all the way to the 1984 cycle as I don't have the '78 and '81 cycles.
Notice that the requirement to make the water pipe continuous has been removed in the 1984 cycle and is not in any cycle from that date.
Why was this requirement removed?

 

[George Stolz]

Perhaps some AHJs were forcing installers to make metallic components of non-metallic water systems electrically continuous? That would explain it.

Truthfully I don't know.

 

[iwire]

Here is what I see.

In earlier additions the section says

"All interior metal water and gas piping that may become energized shall be bonded together and made electrically continuous"

Notice that in the actual wording in the sections text there is no mention of a piping system....it says 'All piping'

Think about that, once plastic supply systems started being used this became a major headache to comply with.

That section, worded in that way would require bonding jumpers to all the metal piping at the end of the plastic supply systems.

Based on that I bet that someone put in a proposal requesting relief from this requirement.

They changed the wording to 'piping system'.

They no longer said 'electrical continuous' because a metal piping system will be electrically continuous by default.

The change IMO was to purposely relive the requirement to bond ten 18" stubs in three different bathrooms on two different floor with a 250.66 sized Bonding jumper.

Anyway thats my WAG.

 

[George Stolz]

Perhaps the members here with impressive ROP/ROC collections (cough cough Don cough) could dig in and see what happened, I'm very curious about the evolution of the this section myself.

 

[jwelectric]

Perhaps the members here with impressive ROP/ROC collections (cough cough Don cough) could dig in and see what happened, I'm very curious about the evolution of the this section myself.

Ditto :-? :-? :-?

 

[George Stolz]

How far back do your ROPs go, Mike?

 

[jwelectric]

How far back do your ROPs go, Mike?

I didn’t start saving the ROPs until the 2002 cycle. I wish I could get my hands on them all.

This topic is one of my favorite to debate as there is no clear verbiage that mandates that a metal water pipe be made electrically continuous.
As Bob (iwire) pointed out there are some who believe that there could be different systems contained in the same system.
The problem I see with this thinking is; any piece of metal pipe would become a system in and of itself making it a requirement to bond the short stubs.

The way I read and interpret article 250 is there is only one case where the metal water pipe is required to be make electrically continuous and that is found in 250.53(D)(1). Here the only part of the metal water pipe that is required to be made electrically continuous is that part where the bonding jumpers and electrode conductor are terminated to earth.

During the same cycles of the NEC where it was required that the metal water system be continuous a three wire receptacle could be replaced and the EGC ran to the nearest water pipe. The same year that the words “made electrically continuous” were removed from 250-80 the relief to run the EGC form a three wire receptacle was removed from 250.50(b) Exception. Allowing the EGC from a replacement receptacle to land on the water pipe was removed in 1993. 250-50(b) Exception is 250.130 in the 2005 cycle. If it was still the intent for the metal water pipe to be electrically continuous there would have been no need to remove the wording from 250.50(b) Exception and this would still be allowed in 250.130 today.

Based on these findings and the language found in 250.53(D)(1) and 250.104(A)(1) I can’t help but to believe that it is no longer the intent that the metal water pipe be electrically continuous.

 

[George Stolz]

This topic is one of my favorite to debate as there is no clear verbiage that mandates that a metal water pipe be made electrically continuous.

Without a checkered flag in sight, how could it be a good race? Nobody wins.

...found in 250.53(D)(1). Here the only part of the metal water pipe that is required to be made electrically continuous is that part where the bonding jumpers and electrode conductor are terminated to earth.

Back up, Mike. There is no clear stopping point for the bonding requirement hidden in that section. Your interpretation is that it only applies to the portion of the pipe relevant to earth contact, the words do not say that.

As to your clever conclusion (and I do think it's very clever), I have one alternate conclusion that could be drawn. Perhaps the CMP's intent is for the system to be continuous at it's inception, but given the harsh realities of life they have resigned themselves to the conclusion that they can't rely on it to continue to be continuous anymore. Maybe?

 

[jwelectric]

Back up, Mike. There is no clear stopping point for the bonding requirement hidden in that section. Your interpretation is that it only applies to the portion of the pipe relevant to earth contact, the words do not say that.

(1) Continuity. Continuity Of The Grounding Path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.

I can clearly see that it is the path that is requiring continuity.

As to your clever conclusion (and I do think it's very clever), I have one alternate conclusion that could be drawn. Perhaps the CMP's intent is for the system to be continuous at it's inception, but given the harsh realities of life they have resigned themselves to the conclusion that they can't rely on it to continue to be continuous anymore. Maybe?

I would agree if the NEC could mandate the plumbing codes but they can?t. I believe that the fact that they can not control the plumbing codes they gave up on the requirement for the pipes be electrically continuous.

I wired a greenhouse a few years ago. They had an over head watering system installed that consisted of one 2? PVC running down the center of the house. Metal pipe arms with spray nozzles were installed to the PVC. Every once in a while a electronic valve would open and the little plants would get rained on.
Should these metal water pipes have been bonded back to the service with a 1/0 copper bonding jumper? This green house had a 400 amp service and supplied a separate building.