My aunt is giving me her old Kiln and I don't know the model but here are the specs she gave me...10 cu ft. The directions recommend a 60amp breaker, she has it tied into her box on a 70amp breaker and the box still heats up. She called the manufacturer and they recommend an 80 amp breaker.
Now my house has 100 amp service.
Can I tie into the box and use 80 amps for firing? If I do does that mean no AC (30 amp breaker). No TV?
Do I need 200amp service? Will this become cost prohibitive?
Also, my studio (garage) is 5 rooms away from the box, that's a lot of wire to be run. There is a box in the garage that runs the AC on
220/240 (?), but this box connects back to the main service in the house.
Check the label on the kiln, it should state the amerage & voltage needed. If the kiln is not tripping a 70 amp breaker, it's not drawing more than 70 amps, just because you are putting in an 80 amp breaker doesn't mean it will draw 80 amps. Usually you want about 10% higher breaker than the load you will actually have on the circut, so if it's rated around 70, you will want the 80 amp breaker so it does not heat up as much as if your breaker were rated close to the actual draw of the device.
If the directions recommended a 60 amp breaker, the device should definitely not be drawing more than 60 amps, even if the breaker is getting a bit warm, and the manufacturer is now recommending an 80 amp breaker. The heat in your aunt's breaker *could* be being caused by a loose connection or use of aluminum wire with a breaker that is not rater for alumimum wire. *Most* newer breakers ARE OK for aluminum, but check the actual package to be absolutely certain.
Make sure your electrical wire you are getting is of appropriate guage to handle the full 80 amps for the lenght of run you are planning. If you are planning on doing this yourself, if you look at the boxes of wiring at the home improvement store, or on a chart near the boxes of wires, it will tell you what guage minimum you need for a particular amerage and lenght of run. The longer the run, the thicker (lower guage number) you need the wire to be. If the wire is aluminum, instead of copper, make sure that both the receptical you are purchasing AND the breaker are rated for aluminum wire, or there could be oxidation/electrolysis problems at the connection point causing over-heating there. (In the heavier wires there is definitely a price difference between aluminum and copper wiring. Also, remember that aluminum will require a heavier guage wire than copper, again refer to the chart at the home improvement store.) Some brands of wire will have a chart on the back of the box that the wire comes in.
If you are going to hire a competent electrician to do the work, he should be able to do the calculations of the guage needed for the lenght of run and it shouldn't be a problem.
Assuming the kiln is drawing a max of 60 amps (since it was originally recommended in the instructions as the size of the breaker) and your AC circuit has a 30 amp breaker, it shouldn't be drawing more than 27 amps, probably less, that leaves you a whopping 13 amps left for TV, lights, fridge etc... I definitely wouldn't be turning on the vaccuum cleaner, toaster, microwaave and all the lights at the same time ;) (The AC should have a label on it with the maximum amerage draw, it could be less than the 27...)
The heat in your aunt's breaker *could* be being caused by a
Please, go ahead and "splurge" for copper wiring. Most kiln manufacturers specify it. Aluminum wiring is problematic. Local building codes may not allow it. You'll sleep better with copper.
More than likely the reason that the "box" is heating up is that your are not running heavy enough guage wire to the kiln. I'm not finding a good chart online, go to your home repair store and look at the chart. Likely you will not be able to run wires more than 20' and my guess is that it will be 4guage wire. This is the huge wire that almost looks line the wire coming into your house. If you are running 5 rooms away, you need to look on the chart for power transmition.
If you are running 14 gauge (most common) you are going to burn whatever structure the kiln is in down. Same with 12 gauge. You might be able to bisque with 10 gauge... but you shouldn't. Look up the chart, and do not skimp on this. If this is seeming too much, call an electrician, whatever hundreds of dollars they will cost will be worth it.
If the breaker box is heating up, it is because it can't handle the current passing through it (possibly due to a bad connection as others have noted). The size of the wire going from the box to the kiln is actually *inversely* releated to this problem: If the wire is too small, its resistance will be higher and *less* current will be drawn through the breaker. The higher resistance of the wire will cause the *wire* to heat up, but the breaker box would actually run slightly cooler (except for the heat coming from the attached wire itself). So yes, heavy wire is needed for the kiln, but if the breaker is heating up that has to be dealt with separately.
Best regards,
Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis
Thanks for all the tips. I will not skimp when it comes to this project. It just went from a DIY to bringing in a proffessional. It will help me sleep better! Thanks again. Tim.
If the directions reccomend a 60 amp breaker, that means the kiln is drawing "less" than 60 to run. When people use a breaker that is too high in the ratings, it heats up instead of kicking off, this can lead to fire. If you think the breaker is hot, you can bet the wire inside the walls are even hotter. The whole point of the breaker is to kick off whenever the kiln exceeds the amount of amperage its supposed to draw, which means if you have a short in the kiln, the breaker will prevent it from turning your home to toast. So don't try to bypass a possible problem by going to a higher rated breaker, instead find out why your kiln might be drawing excessive amperage. It could be anything from a defective switch to the heating coils need replacing. When the coils get caked up they don't produce enough heat and the thermostat will keep drawing power to try to achieve the heat you set it for. Having new wiring installed by a pro is best as it'll meet code and satisfy the insurance companies. While he's there have him check out your kiln. They have a meter which can read exactly what the coils are drawing as well as what the whole unit is drawing. It'll take them less than a minute to check and can give you a lifetime's peace of mind.
I take exception to the statement that if the breaker is too high of a rating it will heat up.
This would mean that a standard 20 amp breaker would be getting hot if you plugged in a cell phone charger drawing 0.1 amps, but would run cool if you had a 2000 watt hair dryer running on the circuit instead.
Assuming that the wiring from the breaker to whatever outlet or device is connected to it, there is no harm in having a larger service running, because that wire should NOT go above a safe temperature before the breaker trips.
OTOH, if the wiring guage/type and length of run is only adequate for a 60 amp breaker, then by no means should he increase the size of the breaker, otherwise if there were a short, the wire could indeed catch fire before the breaker tripped, but having a breaker rated higher than the amperage draw of a device, or combined draw of all the devices on the circuit will NOT cause the breaker to run warmer than it should.
I just scanned through the replies - so apologies if anyone has already said this - but it appears to me that the kiln may be better running on three phase. It sounds like you wont be able to 'run' it safely on a 100amp normal house supply. One of my kilns is dual phase which draws 80 amp on a single phase supply but 30 amps through three phase.
I bought this kiln over three years ago, and havent been able to use it yet as I only have 100 amp single phase supply - but we are renting a building soon which is going to have three phase fitted for us.
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