12/2 wire in contact with Hot water pipe (copper) - Dangerous? - DIY Chatroom

Tryvidy · 04-21-2009, 08:11 PM

Hi,

Recently ran some 12/2 wire for a dedicated 20a circuit from the basement to the attic, up past the cold air return. This is also where the hot and cold water pipes go from the basement to the second floor.

There's a possibility that my 12/2 wire is resting up against the copper hot water pipe.

(I took a picture, but the contact point is 5' away, difficult to determine from the picture alone, and this is in a spot where no man's head will fit, only my arm

Q:
What would happen if the 12/2 casing melted, and further melted through to the hot wire casing:

Would it ground out and trip the breaker?

*** Would it electricute someone if they were having a shower and the hot wire touched the copper pipe?

OR, have I asked a very stupid question?

AND is it impossible for the 12/2 casing to melt from something only as hot as my hot water pipes? (Note: my hot water tank is turned up to max temp)

Thanks again!

220/221 · 04-21-2009, 08:19 PM

Quote:

is it impossible for the 12/2 casing to melt from something only as hot as my hot water pipes?

Yes. You pipe may get to, what....170? It would take probably 300 to melt the plastic sheathing and even more on the wire insulation.

We try to avoid any contact with piping and ductwork, just to be extra safe, but the likelyhood of damage to the cable is nil.

Don't lose any sleep over it. Remember, your water heater has electrical wiring right in it.

You have smoke detectors and insurance....right

rgsgww · 04-21-2009, 08:25 PM

You said past the cold air return, I suppose you mean not through it hopefully.

Even if somehow the hot touched the pipe, if its a metal connection to the meter, the breaker would trip if the pipes are bonded.

kbsparky · 04-21-2009, 08:33 PM

12-2 is rated for 90 degrees Celsius which translates to 194 degrees Fahrenheit.

Real scalding hot.

I doubt your water pipes are that hot.

Tryvidy · 04-21-2009, 08:39 PM

Great, thanks for the speedy replies everyone!

rgsgww, correct, i ran the 12/2 beside - not in the cold air return.

**Scuba_Dave** · 04-21-2009, 08:44 PM

Hot & cold water as in to sink etc?
Not hot water heating?

Many houses have a tempering valve after the Wh & temp is set to 120
I've yet to see a house where the WH temp is set over 140 without the tempering valve - you burn your hands off

Bigplanz · 04-21-2009, 09:35 PM

334.15 (B) would tend to lead me to believe that the romex should be in conduit, as specified. It is passing between floors, correct? Even if it wasn't passing through a floor, I would think that a cable in direct contact with a hot water pipe would trigger the need for 'physical protection,' as per this section.

334.15 (B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit, or other approved means extending at least 150 mm (6 in.) above the floor.