# Insta hot



## Bob Badger (Apr 19, 2009)

15 or 20 is fine.


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## jwjrw (Jan 14, 2010)

I thought it was but saw in my MH book they were figuring the OC at 150% after the 125%. Ive never done that and didn't know if I should of been.


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## Old man (Mar 24, 2010)

Go with the manufactuers specs.


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## jwjrw (Jan 14, 2010)

Old man said:


> Go with the manufactuers specs.


There are none. No specs on nameplate. 422.11(e)(3) says with no nameplate you can size overcurrent up to 150%


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## Old man (Mar 24, 2010)

Then I would run #12.


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## Murphy (Dec 10, 2009)

i thought 125% was for motors.. and surely you never try to load more than 80 percent of the breakers rating.. but if its dedicated i dont see why not


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## Bob Badger (Apr 19, 2009)

Storage type water heaters require that you size the circuit to 125% of the FLC.

I do not think insta hots are storage type heaters.


You can always load a breaker to 100% for up to 2 hrs, 59 minutes and 9999999999999 seconds. (Any time less than 3 hours) See Article 100 definition of continuous load.


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## william1978 (Sep 21, 2008)

You can size the OCP at 100%. I would run #12.


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## Bob Badger (Apr 19, 2009)

william1978 said:


> You can size the OCP at 100%. I would run #12.


Why run 12AWG for 14 amp load when 14AWG is rated at least 20 amps? 

Not that it is a problem just curious.


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## william1978 (Sep 21, 2008)

Bob Badger said:


> Why run 12AWG for 14 amp load when 14AWG is rated at least 20 amps?
> 
> Not that it is a problem just curious.


I have wired many insta hots and the one that they say they are going to use never shows up and install a larger one and my wire is too small. I'm willing to eat the cost between the 14 and the 12 if I don't have to deal with the stupid plumber and his wrong size insta hot or water heater. It might not happen up where you are, but the plumbers around here can never show up with the right insta hot or water heater.


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## McClary’s Electrical (Feb 21, 2009)

Bob Badger said:


> Storage type water heaters require that you size the circuit to 125% of the FLC.
> 
> I do not think insta hots are storage type heaters.
> 
> ...


2 hrs,59 minutes, and 59.999999999999999 seconds:laughing:


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## Bob Badger (Apr 19, 2009)

william1978 said:


> the one that they say they are going to use never shows up and install a larger one and my wire is too small.


That makes a lot of sense. :thumbsup:


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## MDShunk (Jan 7, 2007)

"I need a cut sheet on that", is my typical response. :thumbsup:

Something different shows up, that's change-order time. On the other hand, I can't pretend like I've never wired heavier because of a bad gut feeling or when I thought they were plainly wrong about what they're going to install.

I was at a pre-bid meeting Friday morning for a bunch of stuff getting rearranged on a roof. The book they gave us to bid from was really nice, in that it had nearly complete documentation on every piece of equipment that was presently on the roof or will be added to the roof. Someone put some serious effort into wanting to get accurate bids. The equipment layout had surveyor's latitude, longitude, hours, minutes, seconds coordinates for all the equipment. Some consultant or construction manager got paid big-bucks to develop that spec book. I'd have been okay with feet and inches.


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## jwjrw (Jan 14, 2010)

Bob Badger said:


> Why run 12AWG for 14 amp load when 14AWG is rated at least 20 amps?
> 
> Not that it is a problem just curious.


 





The plans say #12 wire is the minimum. So #12 it is.


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## jwjrw (Jan 14, 2010)

Murphy said:


> i thought 125% was for motors.. and surely you never try to load more than 80 percent of the breakers rating.. but if its dedicated i dont see why not


 
125% is for continuous loads also.


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## william1978 (Sep 21, 2008)

MDShunk said:


> "I need a cut sheet on that", is my typical response. :thumbsup:
> 
> Something different shows up, that's change-order time. On the other hand, I can't pretend like I've never wired heavier because of a bad gut feeling or when I thought they were plainly wrong about what they're going to install.


 I have done the same thing and have had the cut sheet in hand when the plumber has installed the wrong insta hot and then they tell the GC it will take 6 weeks to get the right one and every time the GC ask for the electrician to change because it won't hurt the schedule as much.


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## GEORGE D (Apr 2, 2009)

Dont have my book handy but I'm almost positive you have a 125% demand factor.Someone please ref that.


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## NolaTigaBait (Oct 19, 2008)

GEORGE D said:


> Dont have my book handy but I'm almost positive you have a 125% demand factor.Someone please ref that.


Badger already said that is for storable heaters...do you really think an instant water heater is a continuous load?


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## stars13bars2 (Jun 1, 2009)

Yes it is continuous from the time you open the valve until you close it.


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## jwjrw (Jan 14, 2010)

stars13bars2 said:


> Yes it is continuous from the time you open the valve until you close it.


 
Continuous load = 3hours or more of operation. Not many people shower for 3 hours. Although the plumber on the job could of used a 3 hour shower!:laughing:


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## Bob Badger (Apr 19, 2009)

It is worth pointing out that the load has to be expected to run more than 3 hours not 'might' run more than 3.



> *Continuous Load.* A load where the maximum current is expected to continue for 3 hours or more.


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## Dennis Alwon (May 9, 2009)

NolaTigaBait said:


> Badger already said that is for storable heaters...do you really think an instant water heater is a continuous load?


Heck, I really don't understand why they consider a storage-type water heater continuous.art 422.13.

An electric water heater will only take about 45 minutes to heat from a cold start. Not sure where that rule came from.


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## Fredman (Dec 2, 2008)

I wired a 55 gal yesterday. I swear it came up to full temp in about 25 Minutes


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## NolaTigaBait (Oct 19, 2008)

Dennis Alwon said:


> Heck, I really don't understand why they consider a storage-type water heater continuous.art 422.13.
> 
> An electric water heater will only take about 45 minutes to heat from a cold start. Not sure where that rule came from.


Yep, I agree...I know they heat up in under an hour for sure...


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