Install water heater disconnect switch

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  #1  
Old 05-22-19, 11:15 AM
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Install water heater disconnect switch

Location: Balch Springs Texas

Regular type 50 gal. Water heater (pic 1) is inside the house, away from a garage located breaker panel. So I need to install a D.S. to comply with city. WH has a plug in.

I was thinking a 30 amp double pole industrial toggle switch (pic 2) but my friend tells me yeah but that is not as safe as 240vac Disconnect Switch (pic 3) - that this is spring loaded, it slams on power, best servant to a water heater as it needs & draws full power stat. The former is a simple toggle switch with a tiny contact surface area, not as stat in turning on that power.

Is there any truth to friends saying or are both switches rated ok for home use, which, install of either is just as safe, functional and up to city code?

If it has to be a disconnect switch, I have seen this one that has a toggle switch in it (pic 4). Is this one ok just like the one with a pull down handle?

PIC 1


PIC 2


PIC 3


PIC 4
 
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  #2  
Old 05-22-19, 11:45 AM
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A receptacle and plug is a type of disconnect. Did an inspector claim it wasn't?

Cheapest option is probably a 60a A/C pull out disconnect.

If a home inspector told you this just ignore what he said.
 

Last edited by ray2047; 05-22-19 at 05:17 PM.
  #3  
Old 05-22-19, 02:09 PM
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I phoned City buildings master inspector. He said WH should be hard wired into a DS. That a receptacle and plug is a type of disconnect but because of the on/off cycle that a WH does the plug in could get hot and thus, pose a fire risk. I don't know ... is this true, or really stretching a little too far? He said that the toggle switch is ok but would suffer the same as it has a rating of 30 amps. That a handle type disconnect would be the best way to go. I am sure these types of installs (plugs & toggle switches) are all over the city but if the city could get folks to change to these new recommendations then may be I am a good opportunity? I wasn't gonna mess with the plug in, if I don't have to. But is this true that plug in and toggle switches get that hot?
 

Last edited by bambata; 05-22-19 at 03:38 PM.
  #4  
Old 05-22-19, 04:34 PM
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The plug and outlet would be my least concern next to the braided flex hose.
 
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Old 05-22-19, 05:15 PM
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The appliance pull-out in the fourth picture is all I ever use. Easy to install and inexpensive.

Technically the plug and receptacle is a disconnect but if you pull the plug out or put it in while the heater is active you can get a healthy arc form the current being carried thru it.
 
  #6  
Old 05-23-19, 05:25 AM
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It might be a regional thing, but I've never seen a cord and plug for a water heater. When a disconnect is used, it's always the pullout type hardwired with an MC whip.
 
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Old 05-23-19, 10:36 AM
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That a receptacle and plug is a type of disconnect but because of the on/off cycle that a WH does the plug in could get hot and thus, pose a fire risk.
Yes, a receptacle and plug is a type of disconnect, but I doubt they would ever get hot or pose a fire risk. On the other hand, what the picture shows is a 30 amp dryer receptacle which has no ground, just two hots and a neutral. Water heaters should be hard wired and not plug/cord connected.
 
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Old 05-23-19, 12:38 PM
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I would submit this would be the correct recept


Curious how the industry treats a 20A water heater as a non-plug connected device, but a 40A range is OK. hmmm.

Pic 4 DS is likely less $ though.

ps; a true disconnect switch is designed to be more reliable than a wall switch or even a circuit breaker. If the contacts weld together, it will be obvious during its operation.
 
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Old 05-23-19, 12:47 PM
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The water heater is treated as a fixed device.... not movable like a stove.
 
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Old 05-23-19, 06:44 PM
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The WH does not meet the requirements nor is it listed for a cord and plug connection. A simple less than $10 pullout disconnect is fine.

A 30 amp 240 toggle would also be fine, but more money. It is rated for the current the WH would pull. There would be no issue with overheating.
 
  #11  
Old 05-24-19, 02:22 PM
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I am inclined to get the DS in pic 4 but just to verify, so this Leviton 30A Double Pole switch is OK?
Cost is not a factor, both are priced about the same just $12-13.



Question 2
And is this the correct whip?

And if so, to hard wire this whip to the toggle switch above the Black & Red wires would go to each of the black screws, correct?
AFC Cable Systems10/3 x 4 ft. Appliance Whip

 

Last edited by bambata; 05-24-19 at 02:39 PM.
  #12  
Old 05-24-19, 05:49 PM
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Yes, that Leviton double pole switch will work and so will the liquidtight whip, but there is not really a need for the whip to be liquidtight. It would still be less work and less expensive to just install a 60 amp non-fusible A-C disconnect.
 
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  #13  
Old 05-25-19, 06:34 AM
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Thank you. I think I might have a 30 A switch around somewhere, otherwise I will consider the 60A DS.

On another note....I am curious about smart wifi switches on WH.

I use Sonoff switches to control my yard lights, pool, etc. so I am well familiar with them. I know there are $$$ units designed for WH but I am asking about this specific one (pics below), mostly to satisfy my quest for knowledge on this from you professionals than it is to install one.

I have some basic questions on this unit-rated for 30 amps, 85 to 240vac, watts not listed but what would be correct,
240v X 30A = 7200 watts or
120v x 30A = 3600 watts?

Q1
Based on these does this unit meet rating requirements for a WH? My WH is 50gal., 240vac, 2 heating elements at 4500watts each, total 4500 watts.

Q2
Can this be installed as a DS by itself? Or in that setup it needs a properly rated relay?

Q3
If it can be installed how do you wire it, because it's designed with single hot/neutral in and out lines, while WH has 2 x 120vac lines? Do you wire each hot line into the hot and neutral inputs, then out to each 120 vac hot line?





 
  #14  
Old 05-25-19, 03:19 PM
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The module is rated for 30A @ 250v, so you're fine to use it for your water heater control. What's notated as L/N, is really just Hot/Hot for your 240v water heater.

You'll still need a disconnect, the module doesn't count as a disconnect. It probably will need to go in its own box, unless you use an oversized box for your switch.

Do you really want your water heater wifi controlled?
 
  #15  
Old 05-26-19, 09:11 AM
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" CasualJoe , 05-24-19 07:49 PM
Yes, that Leviton double pole switch will work and so will the liquidtight whip, but there is not really a need for the whip to be liquidtight. ​​​​"

The romex wire coming from the WH to DS does not need to be enclosed in the whip?

I see a solid and stranded type whip. Does it matter or either is fine. Cost is the same for both.
 
  #16  
Old 05-29-19, 02:30 PM
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The romex wire coming from the WH to DS does not need to be enclosed in the whip?

Yes, non-metallic cable (aka Romex) between the water heater and disconnect needs to be enclosed, but it does not need to be liquid tight. I generally see flexible metallic conduit, usually steel, used since it is all indoors.


I see a solid and stranded type whip. Does it matter or either is fine. Cost is the same for both.

I am not sure what you mean by solid and stranded type whip.
 
  #17  
Old 05-29-19, 03:47 PM
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Around here all you see is NM from a disconnect to the WH.
 
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Old 05-29-19, 03:52 PM
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Just my personal opinion..... I'm not big on those China built switching modules. I see a relay that is soldered to a board...... strike 1 and I see screw terminals that are not rated for 30A or large wires..... strike 2.
 
  #19  
Old 05-29-19, 04:41 PM
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yeah; that pcb trace width doesn't give me any confidence. Plus, the wiring diagram can't get straight the L being "LIVE". I see the relay itself carries a UL registered component. But, that doesn't mean the entire product is UL or even safe. It looks like a flail from my computer...

Oh, and if it doesn't carry a FCC ID for the wi-fi, it isn't even legal for sale.
 
  #20  
Old 05-30-19, 12:58 PM
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Around here all you see is NM from a disconnect to the WH.

I used to see them done that way manyyyy years ago, but around here for the last 30 years the wiring had to be in conduit. Preferable individual conductors, but NM cable is Ok.
 
  #21  
Old 06-13-19, 07:21 AM
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The DS is all gussied up, on a tight as a fiddle string budget exactly as I wanted. I learned a bunch new from everyone. Thanx for all your help.

 

Last edited by bambata; 06-13-19 at 07:39 AM.
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