Disconnect for water heater??

Discussion in 'Electrical Forum discussion & Blog' started by hammerslammer, Aug 20, 2007.

  1. hammerslammer

    hammerslammer New Member

    Messages:
    68
    Location:
    Colorado
    I'm moving my water heater and I guess i will need a disconnect at the new location. So i'm thinking a metal box with a double pole single throw 30 amp switch will do. Am I close?? Thanks!!
  2. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    NO! Expensive and more work.
    Use a plain 60A non-fused "pull-out" type disconnect. The type used for A/C installations. They are fully self contained and run about 10 bucks.
  3. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Or

    Use a lock out on the breaket for about $2
  4. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT
    Or

    Maybe he's moving the heater next to the panel so he would not even need a separate disconnect... ;)
  5. hammerslammer

    hammerslammer New Member

    Messages:
    68
    Location:
    Colorado
    No it will be a good ways from the panel. I was checking out the disconnects that Speedy mentioned at the depot and they look like a pretty good deal . They had a 30 amp and a 60. I guess the 60 is recomended because the breaker will be 30a.?? Thanks for the replys.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,990
    Location:
    New England
    By definition, it would seem that if you have a 30A breaker, the disconnect would need to be rated for at least 30A; I think the 60A isn't needed. If I understand this, it's sort of like sizing the wiring, you can't use less than 12g on a 20A circuit, but 10g would be overkill...why spend the money unless you have a very long run.
  7. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT

    60 amp disconnect is a pretty common thing you will find in a home center, and cheaper than a 30 amp...
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,990
    Location:
    New England
    Sounds like a plan, then. I was just figuring the 30A would be cheaper, and was all that was required. Must be a volume thing...
  9. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT

    Yep... Not really even sure why they make a 30a...
  10. cwhyu2

    cwhyu2 Consultant

    Messages:
    1,347
    Location:
    Cincinnati OH
    I would run 10/3wground from your main panel ,install new 30 amp brkr
    unless you need to upgrade your service and panel.
  11. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    I'm not sure what this has to do with the original question about needing a disconnect.

    Also, 10/3 is NOT needed for a water heater. 10/2 is perfect and typical for this installation.
    Using 10/3 is basically wasteful.
  12. hammerslammer

    hammerslammer New Member

    Messages:
    68
    Location:
    Colorado
    How about the idea that (smart) water heaters of the future might requie a neutral?? Just remembering the days when we ran 10-2 for dryers....

    I did price out a roll of 10-2 and 10-3 the other day. More than a water heater.:(
  13. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    Anyone that builds a "smart" water heater that requires a neutral or a 120 Volt circuit has proved that he is not smart enough to build a "smart" water heater.
  14. hammerslammer

    hammerslammer New Member

    Messages:
    68
    Location:
    Colorado
    Right. I was just wondering if it might be "smart" to run a nuetral...

    22 years ago my plumbers tried to talk me out of lowboy gas heaters in the crawlers. I was too "smart" to listen to them.:rolleyes: I'd like to get this chit right in case i last another 22.
  15. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT
    10-2 was never allowed for a dryer...need a insulated neutral.... You were allowed to use the neutral as a ground, but not the other way around...
  16. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    As I scroll down I see Chris beat me to the reply.
    I see old 10/2 all the times used for dryers. This was NEVER code legal NOR was it ever safe!!!!
    Folks who used 10/2 for dryers simply did not know, or care to know, the code.
  17. hammerslammer

    hammerslammer New Member

    Messages:
    68
    Location:
    Colorado
    Wow what a shock for me. I guess i've seen it to and assumed that it was allowed in the past. I have some 10-2 to tear out on my oun house but fortunately it was for a future 2nd laundry room and was never used. Thanks,:eek:
  18. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,608
    Location:
    Cave Creek, Arizona
    10/2

    10/2 w grd was the standard for decades before the 4 terminal plugs were adopted. The difference between a dryer and a water heater is that the dryer has a 120 volt control and motor circuit that needs the neutral, whether it is a 10/2 or 10/3 w ground. And they were always "safe" because the neutral and shell were bonded together.
  19. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    ABSOLUTELY NOT!
    It was NEVER the "standard". At least by anyone who knew what they were doing.
    As has been said now several times, 10/2 has NO neutral in a 120/240v application. This means the bare ground carried current. This was never allowed and was never safe.
    The ONLY exception was when SEU cable was used. This is the service cable that has two conductors with the grounded (NOT grounding) conductor wrapped around them. This exception is now long gone as well.



    Which is the reason for needing an insulated neutral as opposed to a bare ground. Any kind of 10/3 was safe in the past. 10/2 was NOT.
  20. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,608
    Location:
    Cave Creek, Arizona
    10/2

    In that case there were a "jillion" electricians who did not know what they were doing, including the one that wired my new house 6 years ago, to match my 3 prong male plug. As I said, it was standard for decades. You never saw a 4 prong plug for a dryer until the last decade at the earliest. Maybe you are too new in the business to go back that far.
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