# 208V vs 240V heater elements



## joe cool (Jun 4, 2009)

Small restaurant customer bought a gently used electric smoker 120V/208V 24A 4-wire. His building is 120V/240V measured at 230V. What will happen? Tell him to take it back? Order 240V heating elements for it? Let her rip?


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## HARRY304E (Sep 15, 2010)

joe cool said:


> Small restaurant customer bought a gently used electric smoker 120V/208V 24A 4-wire. His building is 120V/240V measured at 230V. What will happen? Tell him to take it back? Order 240V heating elements for it? Let her rip?


4 wire is it 3 hots and a ground? 

Or 2 hots a neutral and a ground?

If it is 2 hots a neutral and a ground then the temperatures will be lower Than normal.


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## 480sparky (Sep 20, 2007)

Install a buck transformer.


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## joe cool (Jun 4, 2009)

HARRY304E said:


> 4 wire is it 3 hots and a ground?
> 
> Or 2 hots a neutral and a ground?
> 
> If it is 2 hots a neutral and a ground then the temperatures will be lower Than normal.


Single phase, 2 hots, neutral, ground. I assume a 120V lamp, timer, fan, something.




480sparky said:


> Install a buck transformer.


What will that cost? Cheaper than making him get the right equipment?


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## 480sparky (Sep 20, 2007)

joe cool said:


> ............What will that cost? Cheaper than making him get the right equipment?


Impossible for me to give you an answer.


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## erics37 (May 7, 2009)

joe cool said:


> What will that cost? Cheaper than making him get the right equipment?


Between $100 and $200 maybe.

Check this out, it's a buck-boost transformer sizing chart from Acme Transformers. Pretty easy to figure out. Judging from that, you'd probably want a T-1-81052, which is a 750 VA buck-boost transformer. The Platt web page lists it at $233 or so, but if you've got a good relationship with the supply house you'll get it way cheaper than that.

http://www.platt.com/CutSheets/Acme%20Transformers/Buck-BoostTransformers.pdf


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## joe cool (Jun 4, 2009)

erics37 said:


> Between $100 and $200 maybe.
> 
> Check this out, it's a buck-boost transformer sizing chart from Acme Transformers. Pretty easy to figure out. Judging from that, you'd probably want a T-1-81052, which is a 750 VA buck-boost transformer. The Platt web page lists it at $233 or so, but if you've got a good relationship with the supply house you'll get it way cheaper than that.
> 
> http://www.platt.com/CutSheets/Acme Transformers/Buck-BoostTransformers.pdf


He got the 120/208 version of this 
http://www.southern-pride.com/_new/m/catalogs/Spec Sheet SC-200.pdf but should have got the 120/240. He bought it cheap and used. I am going to look into the materials cost of replacing the elements. Otherwise he can take it back, I don't want the responsibility of a transformer.

I thought it would burn up faster at 240V.


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## erics37 (May 7, 2009)

joe cool said:


> He got the 120/208 version of this
> http://www.southern-pride.com/_new/m/catalogs/Spec Sheet SC-200.pdf but should have got the 120/240. He bought it cheap and used. I am going to look into the materials cost of replacing the elements. Otherwise he can take it back, I don't want the responsibility of a transformer.
> 
> I thought it would burn up faster at 240V.


There's an old condo building here that utilizes electric boilers for radiant heating in the units. I was out there troubleshooting it one day; the nameplate on the boilers said 208 3-phase but the actual supply voltage was 240 3-phase. They've been installed and running for well over 10 years now. I told the owner what was going on and he said "Cool, so we get extra heat out of it then huh?"

The elements were still original, and they had been churning away at 240V for over 10 years. Who knows.

A transformer isn't much of a responsibility, and it's a pretty cheap solution, comparatively. They're easy to hook up, they send it out with a manual that has every possible wiring diagram in it. You'd have to be a ******** toddler not to figure it out.


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## BBQ (Nov 16, 2010)

joe cool said:


> I thought it would burn up faster at 240V.


It will run much hotter and might be a potential hazard at 240.

I think Harry read your post backward.


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## HARRY304E (Sep 15, 2010)

BBQ said:


> It will run much hotter and might be a potential hazard at 240.
> 
> I think Harry read your post backward.


Good catch....wooops...:whistling2::laughing:


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## John Valdes (May 17, 2007)

How many elements? You could get a little creative with the element connections. The smoker has a thermostat so over heating or under heating should not be an issue.
If it were mine here at home, I would use it on the 240 volts.


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## BBQ (Nov 16, 2010)

John Valdes said:


> How many elements? You could get a little creative with the element connections.


Yeah, if you forget about listings, 110.3(B) and liability.



> The smoker has a thermostat so over heating or under heating should not be an issue.


You are assuming.




> If it were mine here at home, I would use it on the 240 volts.


Same here, at my own home, but not for a customer.


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## CraigV (May 12, 2011)

erics37 said:


> There's an old condo building here that utilizes electric boilers for radiant heating in the units. I was out there troubleshooting it one day; the nameplate on the boilers said 208 3-phase but the actual supply voltage was 240 3-phase. They've been installed and running for well over 10 years now. I told the owner what was going on and he said "Cool, so we get extra heat out of it then huh?"
> 
> The elements were still original, and they had been churning away at 240V for over 10 years. Who knows.
> 
> A transformer isn't much of a responsibility, and it's a pretty cheap solution, comparatively. They're easy to hook up, they send it out with a manual that has every possible wiring diagram in it. You'd have to be a ******** toddler not to figure it out.


Not too surprising, as 240v is only 15.5% higher than 208v.


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## BBQ (Nov 16, 2010)

CraigV said:


> Not too surprising, as 240v is only 15.5% higher than 208v.


True that, but the heat created by the elements is much more than 15.5% higher.


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## I_get_shocked (Apr 6, 2009)

BBQ said:


> True that, but the heat created by the elements is much more than 15.5% higher.


how so? Will a 1500 watt heater will burn hotter @ 240 than at 208? I know power doesnt change


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## Bjack (Feb 24, 2012)

I_get_shocked said:


> how so? Will a 1500 watt heater will burn hotter @ 240 than at 208? I know power doesnt change


Not true. The load doesn't change. From your nameplate data we get this ohms law information
P=1500w
E=208v
Finding 
I=7.2a

From this we find that the heater element has a resistance of 28.84ohms (208v/7.2a=28.84ohms). Now that we have the resistance we can find that at 240v the new amperage is 8.32a (240v/28.84ohms=8.32a) and that the power is now 240v•8.32a=1997w or 133% above the nameplate rating.


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## garfield (Jul 30, 2009)

My suspicion is that the only difference in the 2 units is the elements themselves. How about ordering a new element.......personally I'd use the other one until it burned up which will be a long time i believe.


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## don_resqcapt19 (Jul 18, 2010)

CraigV said:


> Not too surprising, as 240v is only 15.5% higher than 208v.


 There is a 25% increase in the wattage when you run a 208 volt rated heater on 240 volts.


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