[Rconway91]

Hi,
So i recently got an old Cress kiln. The only place I have access to the 220v outlet is on the upper floor in what used to be a kitchen. I have the metal stand everything to keep it of direct contact with the floor. Can I safely use this kiln in my house? Are there steps I should take to minimize fire hazard?

[Marcia Selsor]

I would spend the money for a 220 outlet somewhere safer like outside on a concrete pad or in the basement. with a good vent.
If this is not possible, then make sure you have it at least 18" away from combustible walls and vented. If this is your house, you may want to make sure your homeowners insurance is not violated.

Marcia

[Chris Campbell]

Probably.
This really does not sound like a good plan. Pay an electrician to wire it into a safer location.

[Rconway91]

Chris Campbell, on 28 May 2012 - 02:51 PM, said:

Probably.
This really does not sound like a good plan. Pay an electrician to wire it into a safer location.

Dang yeah that's pretty much what I figured. Thanks a lot for the advice!

[JBaymore]

If that 220 V outlet was for a dryer or a kitchen stove it is likely that the wiring leading to it is not useable for the heavy constant load of a kiln. Yes... you might just burn your house down.

Plus old wiring will likely have some corrosion at the connection points. Bad connections cause heat when current is flowing. Heat in the walls equals fire.

Get a new 220 V installation suited for the kiln. The gauge of the wire used is based upon the length of run from the main panel to the kiln and also the amperage the kiln actually draws at high settings. You also need to see if the kiln was wired for 220, 208 or ??? volts. You need to contact the kiln manufacturer to get specs if you don't have them.

best,

.......................john

[SnowberryPotter]

Rconway91, on 28 May 2012 - 11:32 AM, said:

Hi,
So i recently got an old Cress kiln. The only place I have access to the 220v outlet is on the upper floor in what used to be a kitchen. I have the metal stand everything to keep it of direct contact with the floor. Can I safely use this kiln in my house? Are there steps I should take to minimize fire hazard?

Make sure you're electric/breaker box is also able to take the load of a kiln. I put my skutt kiln in my garage, near the garage door, paid an electrician to put in the 220 outlet. Then a few years later, needed to upgrade my breaker box to handle the load of the kiln as the kiln started tripping my breaker and shutting off. I still avoid running my kiln in the "heat of the day" as to not compete with all the electricity we use to run our A/C. (I live in southern Arizona).

I would never consider running my kiln INSIDE my house. I believe it would burn my house down.

Lindy

[DAY]

Lots of potters run their kilns "inside their house"- including schools! Kiln fires are rare to non existent. The danger of fire is in the wiring/breaker box, and is due to faulty/overloaded equipment. If you are tripping circuit breakers in the "heat of the day" it is because you do not have a high enough amperage main. 200 amps is standard in most residential construction.<div>The best place for a kiln is as close to the main breaker box as possible, and outside, but under cover. A kiln is just a tool, and a simple one, at that.</div>

[teardrop]

Bravo DAY.

Most...if not all kilns are UL listed.....just like any other appliance in your home. To think it's gonna burn yer house down if it is properly wired because it is in a bedroom/spare room/etc in your home is being uber-paranoid, IMO.

As a UL listed appliance, I didn't ask or tell my insurance company I installed it...just as I didn't tell them I run 4000 watts (or more) of grow lights in my garage that draw 40+ amps of power when in operation.

I would be more concerned with fumes from the kiln/off-gassing of glaze/etc. than with a fire.

But that's just me....someone who doesn't usually fall into place all that readily....

good luck gettin' it hooked up and firing!

teardrop

[neilestrick]

Being nitpicky here, but no kilns in the US run on 220. That is a generic term. Electrical service in the US is either 240 volts or 208 volts, and your kiln must be wired according the the service you have. Double check the voltage and phase that the new kiln runs on. It should be 240 volt, single phase in order for it to work with your household electrical service. If the phase is wrong, it'll need to be rewired. If the voltage is wrong, it'll need an element change.

Kilns should not be placed on flooring that is combustible, or has a wooden subfloor, unless 3 layers of cement board are placed under it, extending at least 18 inches out from the base of the kiln.

[nancylee]

I have mine in an inside room, with over 120 inches of snow each year, putting it outside is not feasible. I had it wired properly by an electrician, and it really doesn't get that hot under it and around it.
Nancy

[JBaymore]

DAY, on 29 May 2012 - 07:20 AM, said:

Kiln fires are rare to non existent. The danger of fire is in the wiring/breaker box, and is due to faulty/overloaded equipment.

A number of years ago in preparing for a presentation I was doing as a expert witness (as a proferssional kiln builder and professor that teaches kiln design and operation) on a gas kiln issue/suit for a client, I did an electronic distribution survey on "kiln disasters" to (hopefully <g>) help with that particular case. (Some who frequented CLAYART "back-in-the-day" here may remember that.)

Interestingly, the number of gas kiln calamities of any sort reported were very, very small. (Helped with my case! <g>) The number of electric kiln messes reported actually totally surprised me. Now yes, statistically there are far more electric kilns in service than there are gas kilns.... but it still was an interesting fact-toid. So electric kiln related fires are not non-existant. They may be a small percentage of the total installations, but they apparently DO happen.

Another thing that stood out was the number of cases that I call "near misses". Situations that upon inspection...... the deterioration of a situation became apparent. But it was only through the topic coming up that people checked.

I do not have that data at hand right now.... this was done a pretty long time ago......... but as I remember, probably about 90 percent of the electric kiln issues reported involved the improper installation of the WIRING of the unit or lack of routine inspection and maintenence of that wiring. Most of those problems involved using a pluged connection for the kiln to the electrical supply rather than hard wiring of that connection.

Most involved heat generated at that point because of long-term deterioration of the connection between the plug unit and the contacts in the receptacle. Most involved a fire on the wall where the electrical service was mounted from the overheating of the plug/box. Most involved a wall fire or burned wiring insulation becoming evident at the peak of the firing or just after the firing had concluded.

When I consult on electric kiln installations the issues I typically see with this are plugged connections that have not been even looked at in YEARS... and the copper to copper connections have corroded terribly over time. So the connection's internal resistance has gone up, and this added resistance is creating excessive heat in the box. Or that the connectors for the wires to the female plug receptacle have not been protected from corrosion by the application of a compound upon installation that tends to inhibits this.

Another thing I see frequently is that the electritian who was hired to do the installation job "knew better than the manufacturer becasue they have been an electritian for XX years" and decided to use a lower gauge of wire for the supply line to save some $$ for the homeowner. The person's experience typically came from home-type heating appliances... not large electric kilns with heavy continuous draws at the top end of the firing.

Lower gauge wire increases the Ohms per foot (resistance) of the supply wire itself. This causes the wire to heat up inside the wall as current flows. Correct sized wire does not heat up enough during the duration of a kiln firing to be an issue. Too small a wire can. (Plus there are potential issues of voltage drop at the kiln with too small a supply wire..... separate subject.)

Sometimes I have seen aluminum wire used for this situation also instead of copper...... which is a bit scary.


If you are a hobby potter, installing a UL listed electric kiln in your home is not really a big issue, insurance-wise. As long as you follow the manufacturer's specifications exactly. As has been said... there are PLENTY of electric kilns installed inside people's homes. If installed properly and VENTED properly, they are NOT a big issue.

If however you are selling your work and filing a Schedule C tax form for that business (in the USA), then that kiln is part of a business operation, and that basically changes everything for you. You are no longer covered by your typical Homeowners Insurance policty... and might even be in violation of the terms of that policy. You may also be afoul of some local zoning restrictions or ordinances.... since running a business "at home" in many places is covered by some specific regulations. It may require permits and or special exceptions to do so. Being in violation of such regulations itself can void your Homeowners Insurance policy.

It is worth some research. This all can be a bit more complex than it looks.


best,

.......................john

[Chris Campbell]

Rconway91, on 28 May 2012 - 02:32 PM, said:

Hi,
So i recently got an old Cress kiln. The only place I have access to the 220v outlet is on the upper floor in what used to be a kitchen. I have the metal stand everything to keep it of direct contact with the floor. Can I safely use this kiln in my house? Are there steps I should take to minimize fire hazard?

Sorry, but in good conscience I could NEVER reply yes to this query.

Old kiln ... how old? how well maintained? corroded?
House ... how old? how old is the wiring? wooden frame dry and tindery? any access to proper ventilation? how can people get out if something happens?
220 Outlet ... how old again? how worn or corroded?adequate wiring all the way through to the box?

To tell this person that all is fine and people do it all the time is just not wise. He could have family sleeping in the room next door.

I had my new electric kiln "professionally" wired in the garage and was assured all was fine ... went outside during my first high firing to find fire ripping up the wall, following the wires.
Cool,eh? My daughter was sleeping over that garage.
Next electrician did a much better job and all is well but I still think about what could have happened if we had been asleep.

[Mark C.]

You need to have an electrician check your service out and make sure its up to speed.
I know of several electric kiln fires and it can happen-bad wiring and poor locations caused them. The place did not burn down but the fire dept shut them down.
Both by people who did not understand what was needed or where to put a kiln.
I have no issue on where you put the kiln as long as its a safe spot with all required clearances
and heat shields in place

Old stove wiring in an upstairs this old house sounds sketchy and needs to be looked at.
Mark

[neilestrick]

These are all good examples of why, whenever you hire a contractor of any sort, you should also get a permit for that work. It costs more and takes longer, but then you can have the inspector verify that everything was done according to the kiln manufacturers recommendations. You have to ask specific questions to the inspector. They don't know any more about kiln wiring than the electricians, but you can give them the kiln specs and ask them to verify that everything was done to the specs.

[Gigi]

Rconway91, on 28 May 2012 - 01:32 PM, said:

Hi,
So i recently got an old Cress kiln. The only place I have access to the 220v outlet is on the upper floor in what used to be a kitchen. I have the metal stand everything to keep it of direct contact with the floor. Can I safely use this kiln in my house? Are there steps I should take to minimize fire hazard?

[Nelly]

Gigi, on 29 May 2012 - 11:25 AM, said:

Rconway91, on 28 May 2012 - 01:32 PM, said:

Hi,
So i recently got an old Cress kiln. The only place I have access to the 220v outlet is on the upper floor in what used to be a kitchen. I have the metal stand everything to keep it of direct contact with the floor. Can I safely use this kiln in my house? Are there steps I should take to minimize fire hazard?

Dear All,

I just went through this with my new kiln. My house is old. 1950's war bungalow. The addition where I placed my new kiln is in the garage. I did it according to spec's as determined by the manufacturer and had two electrician's working on it.

Yes, you are right. Some try to save money and do shortcuts. The problem with not doing it to the exact specification is that you can overload your system. For example, the first electrician said "I can do it for you but you can't cook a turkey and have your kiln running simultaneously."

When I spoke to my kiln supplier they said "no, do it to the exact specifications we require to be 100% safe." Thus, rather than using the big plug system they originally installed we went to some other method. I just know I now have a big bunch of wires outside the house for my amperage requirements. It has all passed electrical safety inspection.

Interestingly the one thing they forgot was the installation of a main breaker for fast turn off in the garage. If this was not noticed and something would ever have happened (before I had the main breaker installed), it would have meant I would have had to run into the house and into the basement to make the system shut off. Not safe. It wasn't until I mentioned my electrical situation to a fellow potter in town that he mentioned "did they install a main breaker in the garage." I asked the electrician who inspected it and he sheepishly said "that it was an oversight on their part." Thus, a main breaker has been installed and is in place. A very, very important issue. I'm not sure they would have caught this unless my potter friend reminded me.

As for insurance, here in Ontario, I am listed as a hobby potter. I am not business entitled at this point. Thus, I can donate my ware to local art galleries to auction off as "donations" but cannot under any circumstances sell. They told me there are no if's and's or buts. If a fire was to occur and they found I had sold one pot that my policy would be null and void.

In speaking with another potter locally he said "the irony is that a wood stove passes inspection much easier than an electric kiln." He pointed out " the stove provides a type of updraft of fumes that can be far more dangerous than an enclosed kiln." I think he is likely right on this issue.

Again, I would say, do it the way they want you to exactly. That way your investment is protected. I have the fire wall, concrete floors, exhaust fan, windows open, and metal stand for my kiln. But also, do not forget a main breaker close to the site of the kiln.

I also wondered about a fire alarm system??? I remedied this by having an extinguisher close by.

But yeah, I know my old studio was in the basement of a YMCA with people living above us. It was nothing to fire all night and only check in the mornings when things were starting to heat up and we had to turn the dial up from low to high. Many people just left the kiln and allowed it to go off on its own. I do not think this is a safe practice. I think you need to be close by no matter what.

I just signed my papers yesterday for the insurance. Thus, I am finally good to go as a hobby potter. In a few years, after I have built up stock I will likely change it to a business or liability carrying policy. But for now this hobby status is what I want and can afford.

My thoughts...

Nelly

[SnowberryPotter]

DAY, on 29 May 2012 - 04:20 AM, said:

Lots of potters run their kilns "inside their house"- including schools! Kiln fires are rare to non existent. The danger of fire is in the wiring/breaker box, and is due to faulty/overloaded equipment. If you are tripping circuit breakers in the "heat of the day" it is because you do not have a high enough amperage main. 200 amps is standard in most residential construction.<div>The best place for a kiln is as close to the main breaker box as possible, and outside, but under cover. A kiln is just a tool, and a simple one, at that.</div>

This is exactly what I said...I upgraded the electrical box, the kiln is in the garage near the door, next to the breaker box. It's fine now. I stand by what I said..no way would I run a kiln inside my house.

[Ivar]

From the perspective of a pearson who has an electrician in a family I would like to point out few important things for conecting your kiln to electricity:

1. if your wires are old - replace them, and if you are not an electrician find someone who is expert to do the job
2. it is always better to use stronger wires then you think you might need
3. try to use industrial plugs, they are more resistant
4. make sure that you do not have on same phase all major consumers, like kiln, oven, heaters...

I know there is a difference in US and European standards, but when I installed my kiln, I asked electrcian to check all and to make sure that this wiring is only for kiln, that wires are stronger and asked him to change the plug into industrial one.
My cable or plug are not warimg up at all when firing, and I have also installed safety, overvoltage, and overheat switches.

I keep my kiln in studio, it is just 2" from the walls, but this is not an issue, because our house is build out of solid brick, and on floor I have tiles - meaning no burning materials. Thing is they do not get warm at all.

be carefull, investing money into good wirings is cheaper then rebuliding your house or studio after fire.

[neilestrick]

Ivar, on 01 June 2012 - 01:48 AM, said:

4. make sure that you do not have on same phase all major consumers, like kiln, oven, heaters...

I know there is a difference in US and European standards, but when I installed my kiln, I asked electrcian to check all and to make sure that this wiring is only for kiln...

I keep my kiln in studio, it is just 2" from the walls, but this is not an issue, because our house is build out of solid brick, and on floor I have tiles - meaning no burning materials. Thing is they do not get warm at all.

All 2 or 3 pole (208/240 volt) appliances must be on their own dedicated circuit, meaning the wires from that plug go directly to a breaker. That's basic electrical code. If your electrician wants your kiln to share a line with your oven, then he is a hack.

As for your kiln being only 2" from the wall, that could be a problem. While the bricks are fine, the heat can weaken the cement mortar holding them together. Manufacturer recommendations are at least 12" clearance from any type of wall.

[neilestrick]

SnowberryPotter, on 01 June 2012 - 12:11 AM, said:

This is exactly what I said...I upgraded the electrical box, the kiln is in the garage near the door, next to the breaker box. It's fine now. I stand by what I said..no way would I run a kiln inside my house.

Kilns are safe inside a house, as long as everything is installed properly. If that's your stand, I respect it. Better safe than sorry. But I don't think we should be making people fearful about putting kilns in their homes.

Electric kilns should never be installed outside, even under cover. They should be in a fully enclosed spaced where weather can never get to them. I always tell customers that there kiln should be in a space where they would feel safe leaving a their laptop computer during a monsoon.

Manufacturers recommend putting a fused disconnect box right by the kiln. It adds another layer of safety, and provides an easy way to shut down the kiln if a problem arises.