expert opinion please on new HW heater install


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Old 04-22-16, 05:56 AM
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expert opinion please on new HW heater install

I am installing a new 20 gallon electric hot water heater in our small seasonal cottage.

The watts listed for the Rheem unit are 2000 watts. My plan is to run a new circuit from the breaker box (30 ft away) of romex 10/2, and add a single pole 30 amp switch, located above the new tank (120 volt install) to allow temporarily turning off the HW heater.

The tank will be located in the bathroom, adjacent to a sink, toilet, and shower. I am concerned about the safety aspect of the electric hot water heater, and am considering, as an added precaution, a 30 amp GFI circuit breaker at the breaker box.

Experts, any dangerous flaws in my plan? Is this overkill? Suggestions? Thanks!
 
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Old 04-22-16, 07:23 AM
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Are you sure the tank doesn't require 240 volts?
 
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Old 04-22-16, 07:29 AM
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I had a trailer yrs ago that had an 18 gallon 120 volt water heater but if I remember correctly it was on a 20 amp fuse. I'd be inclined to install a more efficient 240 volt heater and maybe step it up to 30 gallon - or are there space constrictions? Not sure what the safety worries would be as long as everything is wired up properly.
 
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Old 04-22-16, 07:43 AM
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The math says it is on the border line for a 20 amp breaker. Going with 10-2 will future proof the installation for a larger unit and is okay but I'd try a 20 amp breaker first. What breaker size is suggested on the label?
 
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Old 04-22-16, 07:24 PM
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ray2047, the Rheem documentation seems to suggest (for 120 volts) 25 amp breaker and 10/2 wire.

marksr, the safety worries deal with nearby water, someone turning the HW heater on or off using the single pole switch (rather than the breaker)...just an extra peace of mind...perhaps this is overkill?

stickshift, yes, it seems it can be wired 120...

I am definitely not a pro electrician, just a novice amateur...leaning towards overkill if needed, for peace of mind.

thanks
 
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Old 04-22-16, 08:01 PM
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Rheem documentation seems to suggest (for 120 volts) 25 amp breaker
Then use a 25 or 30 amp breaker. Always best to follow manufacturers instructions.
 
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Old 04-23-16, 06:32 AM
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someone turning the HW heater on or off using the single pole switch (rather than the breaker)
If the WH is not within sight of the breaker/fuse a disconnect is required. A disconnect can be a snap switch but it needs to be rated for the load to be served, in you case at least 16.6 amps.
 
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Old 04-23-16, 10:11 AM
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A pullout A/C disconnect will be cheaper than the toggle switch.
 
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Old 04-24-16, 07:18 AM
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thank you gents, for all the comments and suggestions.
 
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Old 04-24-16, 11:18 AM
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A pullout A/C disconnect will be cheaper than the toggle switch.
Very true. A 60A pullout A-C disconnect is about $7 at the box stores and a 30A single pole toggle switch is closer to $20 plus the box, the plate and connectors.

Shop Cooper Wiring Devices 30-Amp White Light Switch at Lowes.com
 
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Old 04-24-16, 11:46 AM
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Disconnect wiring note: If you use an A/C disconnect it is 2-pole but on 120 volt you only use one pole. You will only connect the hot. The neutral will be spliced through.
 
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Old 04-24-16, 05:13 PM
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Disconnect wiring note: If you use an A/C disconnect it is 2-pole but on 120 volt you only use one pole. You will only connect the hot. The neutral will be spliced through.
I don't believe it's a code violation to disconnect the neutral also, is it? I thought you just couldn't disconnect the ground wire.
 
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Old 04-24-16, 05:30 PM
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It was my understanding you don't switch the neutral. Perhaps I misunderstand that rule. The pros will have to have the final word on that.
 
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Old 04-26-16, 04:12 PM
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As long as the disconnect is non-fusible I don't believe it would be a code violation as long as both grounded and ungrounded conductors are disconnected simultaneously. Generally the neutral or grounded conductor is never opened at a disconnect except for in the case of gas pumps when it is required for the neutral conductor to also be disconnected.
 
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Old 04-26-16, 04:30 PM
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The disconnect will not have a place to disconnect the neutral. Just splice it through.
 
 

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