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-   -   Volts in your basic range (http://www.diychatroom.com/f18/volts-your-basic-range-146760/)

Hexamexapex 06-11-2012 07:22 PM

Volts in your basic range
 
I had a friend tell me recently that the range in my kitchen split the 240v entering through the lower half into 110 for the heating elements. He essentially said " 110 up top and 110 on the bottom. I do not think it is that simple. I guess my question is what does my range do with that 240. I don't have the model number but can tell you it's a GE and pretty basic with digital controls for the oven and clock and basic switches for the cooktop. I was thinking that the elements would need 240 and the controls 110v?

Thanks for any and all help,
Marcus

Jim Port 06-11-2012 07:24 PM

The control circuit and a clock or oven light would be 120. The elements are 240 volt.

Hexamexapex 06-11-2012 07:31 PM

Thanks for the quick response. You confirmed my initial thought. So the elements pull from 240v. This is due to the amp rating of the elements correct? Now another question would be is each stovetop element 240 or just the oven elements?

AllanJ 06-11-2012 07:34 PM

Stove top elements are also 240 volt.

Some models have 2 sub-elements in each "burner" and switch different combinations of 120 volts and 240 volts to get low, medium, high, etc. heat. A more modern system varies the voltage and therefore the heat more evenly using a solid state control similar to a light dimmer.

Oven elements are almost always switched on and off (240 volts) using a thermostat and do not have changing voltage applied depending on the desired temperature.

Hexamexapex 06-11-2012 07:41 PM

Is this the same for induction cooktops? Thanks for the info again. This is good stuff.

Protocol. 06-11-2012 08:46 PM

Induction cooktops use a completely different method of heating. It uses waves of magnetic force to induce heat in another object (pot).

It is more efficient to run an element at 120/240V than at 120V.

5000W element if run at 240V will draw 20 amps (in a perfect world)
5000W element if run at 120V will draw about 41 amps. (once again, perfect world)

It gets a little bit more complicated than that because you are dealing with a single-phase 3-wire system. But it's mainly to provide enough power (watts) while still keeping current low (high current = high line loss)

ddawg16 06-12-2012 09:22 AM

Quote:

Originally Posted by Protocol. (Post 941342)
Induction cooktops use a completely different method of heating. It uses waves of magnetic force to induce heat in another object (pot).

It is more efficient to run an element at 120/240V than at 120V.

5000W element if run at 240V will draw 20 amps (in a perfect world)
5000W element if run at 120V will draw about 41 amps. (once again, perfect world)

It gets a little bit more complicated than that because you are dealing with a single-phase 3-wire system. But it's mainly to provide enough power (watts) while still keeping current low (high current = high line loss)

To add to that....the higher the current...the larger the wire needs to be....

To give you an idea....look at how large the battery cables are in your car. Lets say that your starter pulls 400amps when cranking the engine....that is 4800 watts....

For 4800w @240vac....your wire is now only a #10 awg....a fraction of the size of the battery cable.

Additionally....voltage drop is a big issue....

Wire has a give voltage drop for a given current....assume a length of wire has a 1 volt drop for a given current....at 12 v, that is a good % of your voltage....at 120v, your now down to 119...at 240vac, just 239......hence, the higher the voltage, the more potential work you have available.

That is one of the reasons you see higher volatages for industrial motors...typically 3ph 480Vac...

curiousB 06-12-2012 11:04 AM

Quote:

Originally Posted by Hexamexapex (Post 941270)
I had a friend tell me recently that the range in my kitchen split the 240v entering through the lower half into 110 for the heating elements. He essentially said " 110 up top and 110 on the bottom.


He is completely unequivocally wrong.

The elements are all 240VAC as stated here. This lowers the current drain over 120VAC to half (for the same wattage). As a result lower gauge wires can be used to feed the appliance and there will be less voltage drop back to the panel. All good things.

jcrack_corn 06-12-2012 12:06 PM

Quote:

Originally Posted by Protocol.
Induction cooktops use a completely different method of heating. It uses waves of magnetic force to induce heat in another object (pot).

It is more efficient to run an element at 120/240V than at 120V.

5000W element if run at 240V will draw 20 amps (in a perfect world)
5000W element if run at 120V will draw about 41 amps. (once again, perfect world)

It gets a little bit more complicated than that because you are dealing with a single-phase 3-wire system. But it's mainly to provide enough power (watts) while still keeping current low (high current = high line loss)

it has nothing to do with efficiency... 240v x 10a= 2400w
120v x 20a= 2400w

watts is watts

as mentioned it is to reduce wire size voltage drop, etc (all secondary rather than primary efficiency factors) ... same reason we have megavolt transmission lines (among others)

ddawg16 06-12-2012 12:20 PM

Quote:

Originally Posted by jcrack_corn (Post 941754)
it has nothing to do with efficiency... 240v x 10a= 2400w
120v x 20a= 2400w

watts is watts

as mentioned it is to reduce wire size voltage drop, etc (all secondary rather than primary efficiency factors) ... same reason we have megavolt transmission lines (among others)

Correct

But it might be worthwhile to distinguish the difference between efficiency and performance.

Under the same conditions above...both devices would be using the same 'power'....but, because because of voltage drop (assuming the larger wire has half the resistance but twice the current), both would have the same voltage drop. Hence, the lower voltage item would have slightly less voltage available to it than the higher voltage device....

For most of us...not a decerable difference...but when you get into industry....it becomes a big deal....

Side note....in Europe, the standard voltage is 240Vac...but, control panels typically use 24Vdc internally....technicians don't like brushing their elbows up against a 240Vac terminal block....does not feel good.....

I personally don't like anything over 12Vdc.....yea...I'm a wimp....I don't like heights, high voltages or spiders.....


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