more power from 110v?

G

godspeed

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Aug 23, 2010
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I have built my H.T. oven and (besides a few small problems)110v is taking quite a while to heat up. Is there any way I can bump up the power with a transformer or something? Is it a matter of volts, watts, or amps?
I'm losing some heat around the door, but I will fix that shortly.
I know you're thinking "just use 220", but as i'm using someone else's garage that isn't an option for me.

I'm using a 25A SSR, Kanthal A-1 resistance wire, and it's drawing about 10amps..The open space inside the oven is 4"x4"x16"...if that helps.

I don't know much about electricity, and at this point i'm just happy it works at all.... I just wish it would heat up faster.
Any help would be appreciated.
 
At 10 amps and that size chamber it is going to be slow. You could put a higher wattage element in it if your circuit can provide the necessary juice, but 220v is the only way to speed it up much.
 
You need to increase the voltage to speed things up. If you cannot get to the 220v then a transformer will work but that might be on the expensive side. Is there an electric dryer anywhere close by? I used the 220v plug from the dryer for years. Gives enough umph to speed it up. A long heavy 8ga extension cord would be cheaper than a transformer.
 
You need more watts. If you can't wire it for 240v then you need to draw more amps. At 10 amps you only have about 1200 watts, if you can get it up to 15 amps safely you'll be closer to 1800 watts.
 
Guys, you don't just dial up the amps/watts/voltage like it was the radio volume.

The power to your house is 220 with a center tap ( neutral). Thus, the power from each leg at the fuse box is 110V. If the wiring is hooked across both legs, you get 220V.

The resistance of the Kanthal wire is a fixed parameter. In this case the length used draws 10 amps at 110VAC. You can't change that. If you wanted to re-wire the oven with a longer coil, you could increase the resistance, and get more heat ( and draw more amps). You could re-wire it using a 220V coil and draw much more current.

If you hooked the oven up to 220 VAC as it is now, it would get much hotter real fast......and then burn out a few seconds later. Raising the voltage with a variac to 130-150VAC would make it hotter, but would greatly shorten the coils life. Basically, it is a bad idea, and the adjustable transformer would be costly.

110V ovens are slow to heat up, but will work.
220V is a much better way to go....but you have to build it for that voltage.

Just use the oven as it is, allowing it enough time to soak and fully heat up. Even 220V ovens take time to come to HT temps and stabilize ( heat up the lining fully).
 
bladsmth said:
Guys, you don't just dial up the amps/watts/voltage like it was the radio volume.

The power to your house is 220 with a center tap ( neutral). Thus, the power from each leg at the fuse box is 110V. If the wiring is hooked across both legs, you get 220V.

The resistance of the Kanthal wire is a fixed parameter. In this case the length used draws 10 amps at 110VAC. You can't change that. If you wanted to re-wire the oven with a longer coil, you could increase the resistance, and get more heat ( and draw more amps). You could re-wire it using a 220V coil and draw much more current.

If you hooked the oven up to 220 VAC as it is now, it would get much hotter real fast......and then burn out a few seconds later. Raising the voltage with a variac to 130-150VAC would make it hotter, but would greatly shorten the coils life. Basically, it is a bad idea, and the adjustable transformer would be costly.

110V ovens are slow to heat up, but will work.
220V is a much better way to go....but you have to build it for that voltage.

Just use the oven as it is, allowing it enough time to soak and fully heat up. Even 220V ovens take time to come to HT temps and stabilize ( heat up the lining fully).
Click to expand...

+1 :thumbup:
 
amps equal volts divided by resistance. If you raise resistance, the amps drop.
Power (watts) equal amps times volts. If the amps drop the power also drops, thereby heat which is the product of watts disipated also drops.
Wiring this to 220 will produce about 20 amps and 4400 watts. The wire itself may not take the heat. Basic Ohms law works out that your coil is about 10 ohms.
7.3 ohms at 110v will yeild about 15 amps at 1650 watts and will be about the upper limit for most household breakers/fuses on 115v circuits.
If you can get 220 to the unit, I'd say go with about 16 ohms of element wire which will get you just under 14 amps and a little over 3000 watts.
 
Most electrical codes require a circuit not be loaded over 80% of max capacity. That would be 1440 Watts for a 15 amp, 120V circuit. Exceeding this can have at least two potential consequences.

  1. Burning your house down
  2. Possibly voiding your house insurance
We tend to think "It can't happen to me". Probably true... or......... ;)

Stay safe!

Rob!
 
It's maybe worth your while in getting yourself a good knifemaker's HT oven like one of the Paragons. My Paragon uses a standard 110V receptacle, its over 20 years old and I only had to replace the heatting ellements once.
 
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