How to make SURE my electric works before buying kiln?

[sinnae]

Hi WarmGlass, this is my first post! I just moved into a new studio space that has three-phase in the building though not in every room, 220v outlets and 30 amp breakers on that particular circuit.

I'm looking at a Janus 1613 kiln from Paragon which requires 20 amps and 240v. (http://www.paragonweb.com/JANUS1613.cfm)

And for comparison something that might also be an optional, the Jen-Ken Ceram-a-glass 1815 (http://jenkenkilns.com/ceram-a-glass1815-3.aspx), has lowerage amperage (19) but requires a 40 amp breaker. I'm so confused!

My questions are as such:

1. Given that electrical wiring is sometimes mislabeled (for instance, I've been warned that industrial 208 is sometimes called 220), how can I make SURE that the "220v" is compatible with the 240v kiln and that it is 220v after all?

2. Given that it only pulls 20 amps on a 30 amp breaker, does that mean it'll hit max temp of 2300°F more slowly, or is there a chance it'll never reach that temp at all? How can I make SURE the labeled amperage in the shop is correct?

3. How do I make SURE whether there's 3- or single-phase power on that particular breaker?

4. There are power/wood tools being used in the same shop, though probably on a different breaker. Sometimes, from my room all the way upstairs, I can see the lights dim when the tools are running. Is this going to affect my kiln enough to disrupt a firing cycle?

If it helps, I'll be firing glass only to fusing temps 90% of the time, and only expecting it to hit porcelain-firing temperatures once in a blue while.

I want to make sure of those 4 things before committing to this kiln, but I'm clueless about electric and don't know how to test it. Any help at all would be tremendous! I am so lost at sea and I need to commit to a purchase by the end of the month!

[Bert Weiss]

Usually, where there is 3 phase power, they supply 208v AC single phase. This will make a kiln designed for 240v function at around 87% of wattage. This may not be a problem.

Elements do not care about phase, phase matters with electric motors. Elements care about wattage which is volts x amps. So, lowering the voltage, lowers the wattage. Think light bulbs. A 100 watt bulb is brighter and costs more to operate than a 60 watt bulb.

[sinnae]

Thanks for your reply Bert. I will make sure of whether the power is 208 or 220.

If you or anyone still has insight on whether the Janus 1613 (20 amps) will be able to efficiently reach maximum temp (2350°F) on a 30 amp breaker, I would greatly appreciate it.

[Bert Weiss]

Thanks for your reply Bert. I will make sure of whether the power is 208 or 220.

If you or anyone still has insight on whether the Janus 1613 (20 amps) will be able to efficiently reach maximum temp (2350°F) on a 30 amp breaker, I would greatly appreciate it.

The size of your breaker (circuit) can never be too big, it can only be too small. The power of your kiln is simply wattage, or volts x amps. The amperage it draws is determined by the element size and doesn't change on different circuits. So your kiln creates more wattage on 240volts than it does on 208 volts.

[Warren Weiss]

Sinnae,
Most glass kiln controllers limit the temp. to 1700 F max. Why would you want to go to 2300? I believe different thermocouples and element metals are required for the higher temps.
Warren

[sinnae]

Hey Warren, I'm looking into a kiln that can hit Cone 10 for ceramics to occasionally fire porcelain (without any glazes). The porcelain would be less than 10% of the firings, mostly just glass fusing, but it would be a nice option to have.

However, if there is a significant cost or efficiency benefit in getting a glass-only kiln, I would look into that as well, and simply get a crappy ol' used ceramics kiln to fire separately. I don't know much about the differences in thermocouples/elements.

Thanks again for all the info, guys.

[Bert Weiss]

Nichrome elements are rated to 1700. Kanthal A-1 are good for 2300. Both go hotter than their rating. Most elements these days are Kanthal A-1. What makes the difference between a "glass kiln" and a "ceramic kiln" starts with temperature peaks, but is far more about element configuration. Firing glass is more about evenivity. Firing ceramics is about getting everything hot. You can fire either in either style of kiln, assuming you can reach the temperature you need, and are willing to fire at a speed that achieves enough evenivity to keep from thermal shocking glass. When a kiln design is well matched to it's use, firings are quicker and smoother.

[The Hobbyist]

The breaker is there to protect the wiring from the breaker box to the outlet. A 30 amp breaker will trip when you try to draw more than 30 amps (or it should). That means you can surely use a kiln that is only going to pull 20 amps.

Jim "The Hobbyist"

[Kevin Midgley]

The breaker is there to protect the wiring from the breaker box to the outlet. A 30 amp breaker will trip when you try to draw more than 30 amps (or it should). That means you can surely use a kiln that is only going to pull 20 amps.

You assume the wires in the walls are correctly rated for the breaker. It has been known to happen that incorrectly sized breakers are installed........ Just because there is a 30 there doesn't mean it will work at 30.

You need to know the gauge or size of the wire that was used to know if they match with the electrical safety standards.

There may also be an issue with voltage drop depending on the size of that wiring and the distance from the circuit panel you are connecting the kiln to.

Might want to call in an electrician if you can't figure it out.
Way cheaper to call one in for a re-wiring to zero voltage drop than to have continuous voltage drop that you are paying electricity for forever whenever the kiln is fired.

[Bert Weiss]

I have been taught to size a circuit based on never exceeding 80% of it's capacity. As you load the wires in a circuit, it makes them heat up. Over time warm wires dry out the wood around them. Drier wood is more likely to catch fire.

[charlie]

if you're not able to look in the breaker box and answer these questions, then you need an electrician. it would be too dangerous for us to guess what you have.

[Morganica]

I'm with Charlie. Get a good electrician out there and have him look over the setup and make recommendations. I assumed I had 200-amp service because that's what the box said. Turned out I had 150 and some undercapacity wire, which has complicated things.