# What was I looking at and should it be changed?



## smellslike$tome (Jun 16, 2008)

Replaced a 6 yr old 50 gal elec wh yesterday. I didn't notice until I was disconecting the power that the power supply seemed over sized to me. It was not until I had the new wh in and went to reconnect the power supply that I looked more closely at it.

The line was probably twice as big as the romex I am used to seeing. It was in a black jacketed insulation. Inside the outer insulation were two black insulated aluminum wires which had to have the insulation cut off with a utility knife because my wire strippers couldn't strip anything of that diameter. I had shortened all of the wires because there was about 6 inches of loose wiring outside the outer insulation and I hate that so I cut everything down to about 2 - 3 inches and was going to restrip the ends. Had I known how difficult that would prove to be I would have left them alone. Twisted around the two inner black wires was a braid of about 5 - 6 bare aluminum wires which I presumed to be the ground. I had not looked closely at the wiring when I took it apart and since the two inner wires were black with no discernable (by me) differance, I was not sure of the polarity of the wires when I went to reconnect. By this time I was very concerned about what I was looking at. This call was actually a referal from the electric company I use when I need an electrician (mostly just for running wire for tankless installs) so I advised the ho that they should call them out to take a look at it because I am not an electrician but I don't like what I see. Anyway, I got everything reconnected, held my breath, and energized the wh. It seems to be working fine.

Here are my questions:

What is the potential down side if I reconnected the wh power supply with the polarity reversed and would the wh even heat at all?

Would supplying more than 240 volts to the water heater have any impact on the performance/life span of the wh or does it simply take what it needs and no more?

I've always been under the impression that aluminum wiring was very bad. Something about corrosion taking place at the points that the wiring connects to dissimilar metals which eventually caused shorts in the system resulting in fires? 

Can anyone, based on my description, positively identify what type of wiring this was and whether or not it is suitable for what it is being used for?

Should I endure the scorn of the electricians on CT and post this there?


----------



## uaplumber (Jun 16, 2008)

Hate to say it, but those Elec-chickens will be able to help you for sure. Just hang your head and keep your eyes to the floor when you go into their chat.

In good natured fun let me be the first to say "Call an Electrician!":laughing:


----------



## Tankless (Jun 12, 2008)

LOL....LOL
I love to hear stories like that. That oversized wire you were talking is actually service feeder wire. It is not the correct type or size for that application. Will it work? Sure, but the terminations...the connections with wire nuts are a little nerve racking to me as that sort of wire does not use wire nuts. Did you see the size breaker running this thing? That is really the important part. As for polarity, as long as the neutral is connected correctly, there is no polarity to be concerned with this sort of thing. This is kinda like a piece of black iron pipe buried underground on a service main....it will work, but it's not a very good idea.


----------



## smellslike$tome (Jun 16, 2008)

Tankless said:


> LOL....LOL
> I love to hear stories like that. That oversized wire you were talking is actually service feeder wire. It is not the correct type or size for that application. Will it work? Sure, but the terminations...the connections with wire nuts are a little nerve racking to me as that sort of wire does not use wire nuts. Did you see the size breaker running this thing? That is really the important part. As for polarity, as long as the neutral is connected correctly, there is no polarity to be concerned with this sort of thing. This is kinda like a piece of black iron pipe buried underground on a service main....it will work, but it's not a very good idea.


Good! I was worried about the polarity business. I know just enough about electricity to get me or someone else in a world of hurt. I do not run any electric wire. If it is simply a matter of disconecting something and installing something new in it's place, I will do that but that is as far as I go.

Breaker size is 30 amp.


----------



## user4 (Jun 12, 2008)

The downside of aluminum wire is that you have to use larger wire than copper to handle the the same amperage, it is not allowed in al lot of states for anything but incoming service.


----------



## 422 plumber (Jul 31, 2008)

I just changed a water heater and had a brain cramp. There were two black and 1 white in the conduit. I forgot that 220 has 2 hot legs, and that both the blacks were probably hot. I got it right on the 3rd try, after some pretty cool arcing:whistling2:


----------



## Bill (Jun 17, 2008)

Killertoiletspider said:


> The downside of aluminum wire is that you have to use larger wire than copper to handle the the same amperage, it is not allowed in al lot of states for anything but incoming service.


Exactly!
I cant find aluminum wire here as it has been banned. But KTS is right, with aluminum you need about 3 wire size bigger to carry the same load. Upside is it is less expensive than copper. Downside is that when ever current pass's through aluminum it contracts big time causing the wire to move back and forth and in some cases so much it actually wears out the insulation at the staple and can short out.


----------



## Tankless (Jun 12, 2008)

I know of no code where it is allowed in residential applications like this. When I do service upgrades (new panel) one of the things the inspector first asks is if there is any AL wire in the house. If there is, I will fail inspections. Service feeders fall under the poco rules for drops and underground feeders. I am not 100% sure if it is allowed where you are but if it were me, I would have yanked it out...in your case, tell your sparks to bring it up to code. Compression lugs is an approved means to connect AL wire, but that is just at the service drop and at the meter entrance make up. 

AL...depending on its age and make can very easily break with just a few turns of the wire. Are you sure it wasn't AL-CU? That is Aluminum Clad wire....Copper core with an aluminum coating. I know of nowhere to buy it, but it is legel as far as I know. The derating is done at 60 degrees and I forget about the type of terminals (wire nuts - compression lugs) for it. The wire you described is definitly feeder cable, and is in no way allowed inside a residence for branch circuits.


----------



## M5Plumb (Oct 2, 2008)

Bill, KTS on the Money!!! AL wiring should only be in for the service drop. Everything I see now uses hex nuts in the panel to keep em secure. You wouldn't have that in the heater connections and most likely the source point for an electrical fire. Expansion and contraction of the AL is the culprit of those fires, that wouldn't hold up in wire nuts under any circumstances. Good call on gettin Sparky.


----------

