ECN Forum Forums General Topics of the Trade General Discussion Area 150 A Service

>At this time the code does.
Mr Schiff's comment did not lead me to believe that he thinks that this is the case.

What if I don't know whether the waterline is in earth contact for at least 10': are you saying that I have to assume that it is?

>The comments by Mr. Schiff about not using the metal underground piping as an electrode to improve safety of water department workers are not correct.
Actually, I took those as Mr Fleming's substantiation, but I agree that the reasoning was somewhat flawed.

>If we stopped using it as the grounding electrode, but still bonded it to the grounding system inside the building the same safety problem will exist.
I don't know the the very same problem would exist. It might be reduced slightly simply because another path to earth would be provided by the additional electrodes. But Mr. Fleming's problem is not going to go away.

Since there may be a trend toward non-conducting waterlines, I don't regard a waterline as a primary electrode requiring #4 bare copper grounding.

I have not been viewing waterlines as suitable for use as primary electrodes but rather viewing them as interior piping needing to be bonded as close to the point of entrance as practical.

Some waterlines (to wells) are metal only in the part that is cemented into the foundation. It changes to black plastic on the other side. I don't want to dig one up to check whether it could qualify as an electrode - it's easier to assume that it doesn't qualify. I don't mean to argue. But I do look forward to your answer to my question posed above.

I beleive Mr. Schiff's disliking of the h20 line used as a grounding electrode goes back to the very inception of the practice.

There is a North American Water Workers association,(or something close to that), that have opposed this since then.

Should'nt we move this conversation into an ROP thread for the articles mentioned?

(with appologies to Redsy)

>Shouldn't we move this conversation into an ROP thread for the articles mentioned?
Probably so. I'm not sure whether this is a thread that has digressed into NEC 250-50 or a discussion over whether I am making life unpleasant.

DS,

But even if you don't use the water line as a grounding electrode, you still must bond the interior piping with a conductor sized per Table 256-66 because of 250-104.
I don't think there is any requirement to make the bonding connection to the interior piping near the point of entrance. That rule was put in for the connection of the grounding electrode conductor to the water pipe. The reason this connection is required within 5' of the water pipes entrance is to minimize the possiblility of the grounding electrode being disconnected by a non-metallic piping repair.
As far as knowing if the piping is metallic or not, there is not a good way to know for sure unless it is new construction. In service upgrades you can only make a guess based on area practices.

>even if you don't use the water line as a grounding electrode, you still must bond the interior piping with a conductor sized per Table 256-66 because of 250-104.
Okay, thank you, yes, I agree with this.

Bill's original statement referred to a difficult to reach water main. I interpreted this as referring to bonding within 5' of entry.


If I bond to the interior piping at any readily accessible point(s) with electrical continuity with #4 copper, and I am not counting the the main (the part that is buried outside) as one of my electrodes, and my main is bonded with an inaccessible or very difficult #6 and cannot be contacted by any conductor over 50 A, do I need to run a #4 to the main itself, e.g., within 5' of point of entry, in order to upgrade to 200 A service?

DS,

I want to just say yes, you must, but 250-50 uses the words "if available" in the requirement to use the metal underground water pipe as a grounding electrode, so this would be a call of your AHJ. I would not, if I was the AHJ, waive this requirement just because it is "very difficult" to get to the water pipe within 5' of entry.
Don(resqcapt19)

I just finished a 150amp service upgrade on an older home. I used #4 bare copper to my grounding electrodes and the water supply line to the house. The service entrance was rather long, so I was able to save my customer some money by going to 150 amps.

So what is wrong with a 100 amp service? This may well serve the needs of this home for many years to come. As a 150 amp vs 200 amp it is foolish for a few bucks more to not go with a 200. Serve the people not your pocketbook!

So what is wrong with a 100 amp service?

Nothing except that the service entrance cables are usually higher resistance, the busbars are thinner, the cabinets are smaller, there isn't room for the number of circuits an eight room house really needs, and there is no room for expansion when that addition, deck, pool, workshop, or garage is added a few years from now.

I just did a 200A service in a small 2-family, both panels are fed via 100A breaker from the meter/main.

The first flr panel is 42 cir 200A MLO, due to the fact that the owner has almost every device on it's own circuit.

I could, by code, place another 42 cir pan next to the first, the premis being the load demand & diversity, NOT the number of circuit spaces vs. service size.