Water heater using white as second hot for 240

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  #1  
Old 03-26-15, 11:02 PM
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Water heater using white as second hot for 240

So I'm looking into what I would have to do to upgrade my '76 split-level to a modern 200 amp panel myself. I've received a quote for about 2k to upgrade the panel, but this seems like a simple enough job I'd like to see if I can tackle it myself, however... As you can see I have no main shutoff currently, and my panel is separated by a 60 amp "main" for my outlets and lights. First, I have discovered that my house has no grounding rod(s) and seems to treat the ground and common as the same thing (see photo), apparently this was acceptable in the mid 70s? I was all set to go at this myself as it seems fairly straight forward, and yes I'd be installing two grounding rods > 6' apart outside, ok no problem.

But then I found this: My water heater seems to be using both the black and the white wires as hots for the 240 hookup and the bare ground wire as the common. Certainly this is not acceptable right? I'm figuring I'd have to run a new proper 240 line to my water heater, correct? I also noticed that the lines that run to my detached garage and shed (through the conduit you can see in the lower right) are sharing breakers with other lines which is a no-no I know, but now I'm concerned with the gauge and length of those lines (approx. 80-100 ft), looking at them they seem to be #10 but I'm not sure (they're not labeled and I've yet to measure). Any advice would be appreciated.

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To clarify below, the water heater is a dual 30A breaker, you can't see the whole breaker in the photo.
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  #2  
Old 03-26-15, 11:32 PM
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Ah, so I just noticed the bundle of wires that appears to be my ground. I'm guessing I have a UFER ground then, ok, I take it I'll have to install the two ground rods for my new panel to bring it up to code?

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Old 03-27-15, 12:23 AM
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But then I found this: My water heater seems to be using both the black and the white wires as hots for the 240 hookup and the bare ground wire as the common. Certainly this is not acceptable right?
That is the standard way it is done in the U.S. The white is by code suppose to be remarked black, red or any color but gray or green on both ends but often isn't. A water heater is 240 volts so there is no neutral. (The word "common" refers a terminal on a some types of switches but I'm guessing what you meant neutral.)The bare wire is ground. #10 is the correct size for a 30 amp circuit. The distances in a normal size residence do not normally require up-sizing.

Neutral is only used if you need 120 volts. The water heater uses 240 volts only so it does not need a neutral. Some appliances like electric stoves and dryers have both 120v and 240v components so they will have two hots and a neutral. 120volts is derived from the neutral and one of the two legs of the 240v your house is supplied with.
 
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Old 03-27-15, 01:47 AM
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You have what is known as a "split bus" panel. You have a maximum of six, two-pole (240 volt) circuit breakers to turn off in order to shut off power to all circuits in the panel. This was common in 1976 and the six throw rule is still in effect. That means there is NO reason to replace the panel.

As Ray pointed out, strictly 240 volt circuits are routinely wired with standard type NM cable and while it IS required to re-designate the white wire in these cases it is also rarely done. Simply take a permanent marker or some colored tape and re-color the white wire.

It is extremely unlikely that you have a Ufer ground but it is also quite possible that you have no ground rods either. The preferred grounding method in 1976 was connection to the metallic water piping serving the house. You MAY, of course, add a grounding rod if you desire but most likely it won't actually make the installation any safer. Also, since the grounding rod IS supposed to be completely buried you may have one and not even know.
 
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Old 03-27-15, 04:47 AM
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If you need a 200 amp service and the existing panel is much less then you will need to do a major upgrade. But nothing is really out of whack now. You can and should procrastinate for awhile while you study things and learn more about what you have. Then make a leisurely decision on the exact steps (choreography) you will use for implementing your new 200 amp panel and system.

Find all the fat wires going to and from the neutral terminal strip (neutral bus bar). The connections to the water pipe, ground rods, etc. are typically #6 gauge copper wires. A "Ufer" ground is a bar embedded in concrete. For a 200 amp service, the wire going to the water pipe or the concrete encased rod needs to be #4 gauge although #6 is the maximum that would ever be required for connecting the panel to ordinary ground rods.

When you make the panel upgrade, you will need two ground rods if you don't already have them. (Some obscure exceptions apply.)

In some cities the new panel will need a separate permit and inspection sequence. This can be a mixed blessing. One possibility is installing the new 200 amp panel but keeping the old panel in use (connected to a breaker set in the new panel) while new circuits are added and/or existing circuits moved to the new panel. Although you may end up keeping some circuits in the original panel, you will not pass final inspection for the general wiring unless certain changes are made inside the original panel namely separating the grounds and neutrals. With the separate permit for the new main panel you could have that part finally inspected while you reconfigure the original panel and circuits at more leisure.

A separate approach (space permitting) is to keep the original panel as a co-main panel with the new panel next to it. No revamping of the original panel grounds and neutrals is needed. One of the breakers in the top half of the original panel needs to be decommissioned immediately since the house power must be able to completely shut down using at most six breaker handles, here, one in the new panel and five in the original panel.

It is suggested that someone with a lot of experience install the 200 amp panel and wire up its top breaker when the time comes. If the homeowner is allowed to do any electrical work of his own then he may populate the new panel himself.

If the building has reinforced concrete below grade then one "Ufer" (more correctly "concrete encased") grounding electrode is required. An exception is if the building was constructed before a certain date then you are not required to chip away concrete to make contact with re-bar.
 

Last edited by AllanJ; 03-27-15 at 05:38 AM.
  #6  
Old 03-27-15, 05:52 AM
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A lot of good information from all. I will just add that even the white being used as a hot pre-dates the requirements to be marked as a hot. That is a more recent change. I was understood by people in the trade as a hot.
 
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Old 03-27-15, 10:28 AM
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Thanks for the input. Glad to hear nothing is too out of whack so far. There is definitely no ground rod anywhere along the periphery of my house (though I know it needs to be close to the meter). Also there is no water connection anywhere within 50 feet of the panel as the wire runs (my water comes in through the garage on the other side of the house and the only thing attached to it is a copper water line to my fridge in the kitchen, inventively enough...). Half of my lower level sits below grade. My only conclusion is that it must be a concrete encased electrode in my foundation.

My ultimate goal is to run a 100 amp sub-panel to my detached garage for a future-proof wood shop (despite the existing conduit I understand I'll be re-trenching and running larger gauge). I suppose I could move one of my breakers from the left to that first spot on the right and put a two pole 100 amp in its place (I'll also have to upgrade the "main" breaker to 100 amp). I'd like to upgrade the panel to bring it up to current code requirements and replace the aging breakers as some of them have a hard time switching back on when tripped. I'm reading that no matter what current ground I have if I do this I'll need to install two ground rods to meet code.
 
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Old 03-27-15, 12:20 PM
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I would guess there's probably a rod below grade somewhere. Probably installed before the backfill and final grade so the thing could be a couple feet deep. I've seen them under the basement slab too. Also possible the grounding wire runs to your water service under the slab. If you were to replace the panel (which I don't think is required at this point), you would most likely need to run a grounding wire to the water service entrance and also install one additional rod. If you have metal municipal water connection it must be your primary means of grounding, plus one additional method. All that said, I don't think any of this is really necessary at this time.
 
  #9  
Old 03-28-15, 05:57 AM
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But first, do you even have a fat ground wire coming from the meter box or from the primary breaker panel or from any place in between? If not then no point looking for ground rods.

You can (and must) add a fat (typically #4) grounding electrode conductor to a metal water pipe exiting the house underground even if you have to run that wire all the way across the basement. The wire must be attached upstream of the water meter and within 5' of where the pipe exits the house.

The ground wire does not have to be installed yesterday and the performance of the electrical system will not change when you install the wire.
 
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Old 03-28-15, 08:11 AM
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There is definitely no ground rod anywhere along the periphery of my house (though I know it needs to be close to the meter). Also there is no water connection anywhere within 50 feet of the panel as the wire runs (my water comes in through the garage on the other side of the house and the only thing attached to it is a copper water line to my fridge in the kitchen, inventively enough...). Half of my lower level sits below grade. My only conclusion is that it must be a concrete encased electrode in my foundation.
I seriously doubt it. In the '70s, a Ufer ground was totally unknown in residential construction. At that time, the service could have been grounded to either a ground rod OR the nearest cold water pipe; both grounds were not required. Considering that the contractor installed a split bus panel, the cheapest panel available at the time, it wouldn't make sense to find a Ufer ground or a long run of copper wire to a cold water pipe. That being said, it would very rare to find a service of that vintage with no ground at all. A GEC to a buried ground rod could have been terminated in the meter socket, have you checked around the socket for a bare GEC?

If this were my home and I wanted to upgrade to 200 amps I would just replace this panel with no less than a copper bus 30 space, 40 circuit main breaker panel. I know there is nothing inherently wrong with this panel, but to me a split bus panel screams CHEAP! My second choice would be to use the existing split bus panel as a subpanel from a new 200 amp main breaker panel.

You should check with your AHJ to see if a homeowner is able to replace the service himself. In my area a homeowner can take a test and then be able to take out his own electrical permits, but a homeowner is not allowed to replace a service.
 
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