230.54

[mc5w]

Re: 230.54

I have seen an instance where water went into a rectangular meter socker through the upper cable and dripped right down into the lower cable. That means that a factory installed drain hole does not necessarily provide any protection.

The requirement for a piped drain only applies in 3 situations. The first one is the very rare service where a weatherhead is outside of an explosionproof area and some of the service equipment needs to be explosionproof. The second situation where service equipment needs to be dust-ignitionproof would apply to farms, bakeries, and grain elevators. The 3rd situation is a bushing type supply riser such as for over 600 volt services where the service is more elaborate anyways.

Since a transformer vault is usually required to have a reliable floor drain anyways, the requirement for a piped drain is not a hardship. Rather, the likelyhood of a bushing type supply riser admitting water is a bit higher and the requirement is just there to require something more professional than water dripping out the bottom of a pull box.

[ April 16, 2005, 02:27 AM: Message edited by: mc5w ]

 

[mc5w]

Re: 230.54

I added a little more explantory text to the reasoning portion.

 

[iwire]

Re: 230.54

Originally posted by mc5w:
I have seen an instance where water went into a rectangular meter socker through the upper cable and dripped right down into the lower cable. That means that a factory installed drain hole does not necessarily provide any protection.

MC You don't have to convince me that a meter can become filled up, drain holes get blocked from insects or dust, water can come in faster than the drain holes can handle.....



JMO, Bob

[ April 16, 2005, 05:29 AM: Message edited by: iwire ]

 

[jwelectric]

Re: 230.54

you go Bob

 

[mc5w]

Re: 230.54

iwire,

That meter socket looks like the underground wiring is being exposed to a water main break. Am I correct? NEC requirements do not address exposure to a water main break and something that catastrophic is going to break a lot of things besides the electrical service. Likewise, a strong enough tornado, hurricane, or earthquake will knock down the whole building.

A lot of people including both electricians and inspectors do not understand the purpose of 230.54(F) which is to keep stranded wire from acting as a water hose. The purpose of putting the weatherhead above the point of attachment is to make putting the splice below the weatherhead an alledged no brainer.

Right at the west end of of my street there is a commercial 120Y208 volt service where the weatherhead is above the point of attachment and Cleveland Electric Illuminating Company's electricians found a way to stick the splices above the weatherhead.

300.5(G) does not address the need to seal service cables SHEATHS against water flowing between the the sheath and the insulation of the conductors.

Also, water does not have to reach the meter socket of service panel to damage something. If it internally corrodes the wire strands then you are in trouble already.

I also do not think that packing a weatherhead with duct sealant or RTV is an extreme measure but is rather prudent. Same goes for using pigtails that have a strand blocking compound when the weatherhead is below the power source.

Open wiring also needs to be spaced enough from building walls that service conduits can pass between the wall and the open wiring.

 

[iwire]

Re: 230.54

Originally posted by mc5w:
That meter socket looks like the underground wiring is being exposed to a water main break. Am I correct?

No water main, just a difference in grade from the transformer to the house.

Originally posted by mc5w:
A lot of people including both electricians and inspectors do not understand the purpose of 230.54(F) which is to keep stranded wire from acting as a water hose.

I have no doubt that many times that is true.

Truthfully IMO if we where to look at installations that have water ruining through the conductor or the cable sheath we would see that code sections had been ignored during the installation in the first place.

Bob

 

[mc5w]

Re: 230.54

Bob,

That much water was getting into a padmount transformer or handhole?

I hope that you noticed that I put "reliable gravity drain" before "sump pump". The requirement is not that extreme but rather that I have seen water continually pour out of the service raceway entering a basement and nobdoy bothered to do anything about it.

The other thing is that some redundancy in some Code sections helps clarify things. If you have 1 section referring to others pretty soon NEC reads like stereo directions.

 

[George Stolz]

Re: 230.54

Originally posted by mc5w:
The other thing is that some redundancy in some Code sections helps clarify things.

Holy smokes! Michael, do you really think this proposal makes anything clearer?

The first reply to it is on page two!

 

[mc5w]

Re: 230.54

I am going to rewrite this proposal sometime in the next week and I will offer 2 alternate forms. Right now I cannot stay up late. Initially, I wanted to jot down some ideas and gets some comments back. I also believe that 230.52(F) is in the wrong spot.

And
Bob, why don't you send that photo of a flooded meter socket to Joe Tedesco to publish in Electrical Construction and Maintenance magazine.

 

[vancedks]

Re: 230.54

could anyone help me out in a my search for information, pictures, and instances of cable damage, corrosion, and water flow between sheath and conductor in regards to "capillary action" or "cable wicking"

 

[mc5w]

Re: 230.54

vancedks,

There was a question in the main NEC forum as to whether of not water can flow between the strands of service condutors. The question came up in an instance of where overhead service conductors originate directly at the terminals of an overhead pole mounted transformer.

Also, I have seen an instance of a meter in a ring type socket where the meter was partially ajar. This is a very obvious safety hazard both because water can enter and because the upper jaws are partially engaged. Cleveland Electric Illuminating Company's meter reader has never noticed this and I keep telling the homeowner to call CEI and have the meter reseated. The homeowner does not seem to appreciate the safety hazard. Evidentally, an chunk of ice detached from the gutter and clobbered the meter.