What will happen to AC cable that was submerged ?

[flashlight]

Our company has been working on buildings that were partially submerged by Sandy, replacing cable and other parts that were submerged.

In one neighborhood, people who didn't want to spend the money found an electrician (apparently there are a few of them) who said the submerged cable would be OK, and he signed them off with just replacing devices.

Now some of our customers are questioning whether they really needed to spend the money--I showed them the NEMA information, plus some other links including this website that convinced them they had done the right thing.

What stinks about the situation is that the AHJs are leaving it entirely to the discretion of the electrician whether the cable should be replaced. So some people are endangering their houses and neighbors through cheapness and/or ignorance. To my knowledge it's not stated anywhere in the code that cable should be replaced under these circumstances, isn't this an oversight ?

 

[petersonra]

The reality is that the wiring is probably just fine.

A lot of people just don't have the money to replace wiring that can be left in place.

 

[augie47]

I think I would be a bit more worried about AC and NM cable than I would some others due to the paper "filler".
Here is an article from Southwire that discusses the cables:
http://www.southwire.com/support/GuidelinesForHandlingWaterDamagedElecWireAndCable.htm

In answer to your question, I don't know that there is a strong black and white Code referece...as with other things it might5 be a matter of opinion, but the Code does state AC is for installation in DRY locations and 110.5 and 110.11 address wiring methods not being used in a manner other than intended and not being subject to deteriorating agents.

 

[renosteinke]

AC, MC, and Flex are not water-tight at all. Any water that got in will just as easily leak out. I would not worry about it much.

 

[flashlight]

Here is an article from Southwire that discusses the cables:
http://www.southwire.com/support/GuidelinesForHandlingWaterDamagedElecWireAndCable.htm

This publication, plus the NEMA Guidelines For Handling Water-Damaged Electrical Equipment, state that cable rated for use in dry areas only should be replaced. Most new AC and MC cable have wire such as THWN, however the cable itself I think is rated for dry areas only.

What I was wondering, has anybody observed cable that was flooded by saltwater, a couple years or more after the fact ? My own impression is that perhaps the metallic cover could rot away ? I don't know, this is my first flood, just trying to get a handle on it.....

 

[infinity]

IMO if it's submerged in salt water it needs to be replaced, especially if there is a AC connector involved. You cannot guarantee that once the salt water entered the connector that the ground continuity wasn't affected even it's not readily apparent right now.

 

[augie47]

IMO if it's submerged in salt water it needs to be replaced, especially if there is a AC connector involved. You cannot guarantee that once the salt water entered the connector that the ground continuity wasn't affected even it's not readily apparent right now.

excellent point

 

[hillbilly1]

Yeah, if its salt water, I think I would worry about it, if its freshwater, it would eventually evaporate, connections such as devices would be the issue.

 

[infinity]

The New Jersey Division of Consumer Affairs has issued this guideline:

November 2012

The Department has issued the following guidance for use in addressing electrical systems in the aftermath of Hurricane Sandy:

? Panel underwater
o Pull the meter
o Clean and dry all breakers and bus bar
o Reinstall breakers necessary for temporary occupancy and restoration
o Within 90 days, all breakers and bus bar must be replaced. In lieu of replacement,
the bus bar may be certified by a licensed electrical contractor


? Wiring underwater
o If undamaged, no replacement is necessary
? Other equipment and outlets (receptacles, lighting, switches, alarms, etc.) underwater
o Within 90 days, all other equipment and outlets must be replaced

http://www.state.nj.us/dca/divisions/codes/

 

[G._S._Ohm]

"? Wiring underwater
o If undamaged, "

This is maybe a PC answer.

I'd think the flood water from Sandy was mostly salt water or brackish water and contained all kinds of nasty stuff, and salt water corrodes copper.

One question is: How fast will the effective cross section of the conductors be narrowed, and by how much?

And is Romex insulation salt-water-permeable?

 

[zog]

I have a ton of data about salt water exposed cable failures froma big EPRI study but that is all focused on MV cable, but that data suggests the NEMA recomendations are accurate and it should all be replaced. Might now fail now but will fail eventually. At the very least, I hope all these guys are meggering the cables before "blessing themn off" as being certified.

 

[weressl]

I think I would be a bit more worried about AC and NM cable than I would some others due to the paper "filler".
Here is an article from Southwire that discusses the cables:
http://www.southwire.com/support/GuidelinesForHandlingWaterDamagedElecWireAndCable.htm

In answer to your question, I don't know that there is a strong black and white Code referece...as with other things it might5 be a matter of opinion, but the Code does state AC is for installation in DRY locations and 110.5 and 110.11 address wiring methods not being used in a manner other than intended and not being subject to deteriorating agents.

I think both of your assertions are stretching the original intent and meaning of the requirement.

The counter-argument would be:

1. The installation was exposed to water, but it is not exposed now and the water was allowed to evaporate - dry-out - from the components.
2. Water is not a deteriorating agent in itself and it has to be proven/disproven that the limited time water exposure WITH the potential presence of otehr agents, such as salts indeed acted as deteriorating agents causing permament damage to the insulation.

 

[flashlight]

Thanks for answers everybody. When I review what everybody said, it seems there really is not a consensus in the industry !

 

[weressl]

Thanks for answers everybody. When I review what everybody said, it seems there really is not a consensus in the industry !

The outlying parameters are ambigous, there isn't a single or simple way to test, in some cases the testing itself would be at elast equivalent in cost of replacement, etc.

So it is an old, complex and ambiguous subject. A.d as with things old: it Depends......:lol:

 

[puckman]

We had salt water enter our galvinized conduits that are in class1 div1-2 areas and nonclassified area . would salt water attack this kind of conduit ? We rebuilt alot of the xproof lighting and just reused the housings.

 

[weressl]

We had salt water enter our galvinized conduits that are in class1 div1-2 areas and nonclassified area . would salt water attack this kind of conduit ? We rebuilt alot of the xproof lighting and just reused the housings.

Yes, salt water would be detrimental to the XP qualities of a sealed conduit or any other XP equipment that relies on the strict maintenance of the explosive relief gap. Since it is unquantifiable of how much corrosion occured, all bets are off. (I am somewhat suspicious this being one of the resons why our EU collegaues do not like XP method of protection.)