Evenheat on Japanese (100 V) Power?

T

Tenebr0s

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I'm looking into getting an electric kiln here in Japan. Unfortunately, there is no kiln here that is remotely within the price range of an Evenheat or Paragon. The smiths here who do go the precise heat treating route (there are more than you may think) are usually doing large batches in molten lead pots. Again, way pricier than I can do right now.

Getting 3 phase power is not an option for my shop, so I'm left with household 100 V. I've never had a problem running any of my American appliances here, but I'm wondering about whether this would be the case with an HT oven? I'll probably go with an 18" Evenheat, if I can be sure it's going to work over here. I'm only doing carbon steel, so getting to those higher temps for stainless isn't a concern, but I do need it to be able to get to HT range for carbon steel.

America is very fortunate in having good equipment geared towards the home shop! I find that here in Japan, you often are choosing between cheap, under-built equipment, or excellent, extremely expensive machines for industry.
 
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You should talk to the folks at Evenheat about this. The obvious issue is that at 100 volts you'll only get 80% of the heating that you'll get at 120 volts. So you may not be able to get the temperature of the oven as high, which you may be OK with. Or you may be able to add insulation to the exterior of the oven to slow heat loss. But a bigger issue is that the control electronics may not be happy with only 100 volts. If the Evenheat won't be happy with 100 volts, it's not all that big a load at 13 amps. You can probably source a 20 amp "buck-boost" transformer in Japan to boost the 100 volts up to 120 volts. Or if you only have to boost the voltage going to the control circuit and not the heating coils, you could get by with a much smaller boost transformer, but it will take some electrical knowledge to separate out the wiring and hook up everything correctly
 
Electronics for kiln usually works correctly from 100 - 240 V AC, sometimes are constructed to work from 90V. But You have right about power loss at 100V. I see that DIY kiln will be best way for You.
 
You'll definitely need to check with the manufacturer.

As said, control voltage and power voltage are potential problems.

The power will vary as the square of the Voltage. 100V is 83% of the 120V design Voltage and 83% squared is only 70% of the design power. Gut feeling is that it should be able to reach Carbon steel temperatures,but that it'll be tight.

Max temp for the Evenheat KH418 is given as 2200 degF,1204 degC. Call that 2140 degF above ambient. 70% of 2140 would be 1498 degF above ambient, so 1558 degF.

This assumes the losses are directly proportional to the temperature difference and is a worst case scenario. The Insulating Fire Bricks actually become poorer insulators as temperature rises, so you should do a little better in reality.

Although Austenitizing temperature for most Carbon steels should be attainable, it will be very slow. This may have an effect on the amounts of scale and decarb you see.

As suggested, a buck/boost power supply might be the best off-the-peg solution. Otherwise, you could probably get a simple transformer wound locally to do the job. I think an autotransformer should be fine and will be much cheaper than an isolating transformer of similar rating.
 
Talk to someone who understands power in Japan and ask for a step-up transformer to convert 100V to 120V. Make sure it is rated at 20 amps ( or at least 5 amps higher than the kiln max draw). This is a very simple setup where the primary has a plug for connecting to the 100V and the secondary has a socket for the kiln.
 
Talk to an eletrician here. They will sort you out. I was considering the same thing a few years back but decided the best for me was to just farm out heat treating. Good luck.
 
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