For all those electricians

[Bryan]

I know some of you guys know a bit about electricity...

Im getting an kiln that runs on 240v and my place is 3 phase 208v.
My question is what do i have to do if anything to make this work?

[Rowdy]

Buy a transformer to convert the 3 phase > 2 phase 240. You must be in a industrial area because that's normally a heavy duty electrical set up. All houses are 2 phase 240v. Shouldn't be a problem go to an electrical distributer and they should be able to get you the transformer you need.

[Natedizzle]

With a 120/208v three phase system, each single leg is 120v and any two together will give you 208v. running a 240 v kiln on 208 will simply slow it's heating time a little.

What kiln are you getting? If it is still being built they can alter the elements accordingly...

[Campy]

^some good info right there!

[Bryan]

thanks nate...i believe it has been built its the hops kiln from aim

[ALIEN!]

I worked in a fabrication shop that had similar issues, they called the power company and they hooked us up with the transformer for free. I think they lacked 480 service and were transforming up to that, and since 480 is more efficient, that's why they gave it for free, like an incentive type thing for business to be more efficient or something. Just throwing that out there. Might be able to get the same kinda deal.

[Rowdy]

Yeah I don't think in apprenticeship school they ever taught us that trick Nate, not sure where you learned your electrical but there are codes for a reason. I'll agree with you on "it'll work, just take longer" but, in the end when something is designed to be used one way and it's run different it usually equates to major failure eventually sooner than intended. It's like running a kiln on a extension cord (awg. 14) hooked to a 15 amp breaker, it's just not going to run efficiently. If you run a 3 phase system unbalanced you'll run one leg hotter than the others.
There is always many schools of thought on how to get things done, some are get-er-doners and then you have the crowd that gets it done right the first time. Electrical and ventilation are two things I don't f@#$ around with! Just remember Darwin is watching!

Good luck, peace

[Waffles]

"If you run a 3 phase unbalanced you'll run one leg hotter than the others. " not true or if it is it won't be a problem maybe an obstacle if you have something else plugged in the same circuit that goes in and out of phase causing some weird not 100% efficient way to use the electricity but really you'll be fine hooking up one kiln to its own breaker
it will run fine with 208 just be sure to have a breaker that is rated for higher amps than the kiln requirements because the load rated on the kiln is what will be pulling fulltime where as the breaker is rated for peak max usage.
I have a 3 phase paragon iguana that used to run on a converter in my garage without three phase and it worked fine just toke longer to warm up and the elements would come on at differant rates than how i have it set up now which is industrial 480 3phase and it is much more efficiant and blasts right to temp.

rampdown times can be completly differant when changing the electricals. the longer it takes to get to annealing temp the more the heat has soaked into the bricks. Therefore the rampdown time when you turn the kiln off will be longer or shorter accordingly. Now that I have my Paragon iguana hooked up to real three phase it gets to annealing temp instantly but if I turn it off within 30-60min the cool down cycle is to quick for larger marbles. Where as wired before once I hit annealing temp it would take 12 hrsish to cool off because the heat was all soaked in the bricks.

[Rowdy]

Mr Waffles you apparently don't know much about electricity, or enough to get yourself or someone else hurt. If you think I'm wrong go talk to your towns electrician. You definitely need some education on 3-phase electricity! I don't have the time to get in an internet throw down on who knows more.

You rate your breaker off of a % of full load amps not "higher amps than the kiln requirements". I suppose you size the wire by whatever you feel like too, or maybe whats cheapest?

[Bo Diddles]

Rowdy, Waffles is bang on, while you are wrong. Trust me.
Great post Waffles, you nailed it.

[STROKER]

i have to say this is a subject that can get someone hurt if they dont pay attention to what is going on.
i have 12 years in commercial electrical work under my belt from a lifetime ago and i worked 3phase power quite often. with that said there are alot more variables to getting even single phase power than has been mentioned so far.

if you set it up yourself, make sure you use an amp meter on each leg to make sure you are pulling even draw or one of your wires could(will) get dangerously hot.

also, when it comes to electronic control boards which most kilns have, there isnt any room for uneven load balances as this is a sure fire way to shorten the life as well as not get consistant results from said machinery.

as long as you follow proper protocol , there is no reason to think you cant get single phase from three phase.

here is a quick copy and paste of the very basics of 3 phase.

be careful , electrical work should always be done properly...


Types of 3-Phase Power


Common 3 Wire Type

Common 4 Wire Type

Special 4 Wire Type

3 Wire w/Grounded Hot Leg
The type of 3-phase power normally doesn't dictate the operating voltage. Usually, a voltage meter is required to determine the actual voltages available, which will also give you some clues about the type of 3-phase. It is extremely important to perform all the tests, especially if you suspect 3 wire w/grounded hot leg and will be using only two legs or you may create a dead short with your connections.

For traditional reasons, 110V/220V are used, but the actual voltage may be 120V/240V or 125V/250V. It will make more sense, especially when discussing 3-phase power, as you will see later. If this bothers you, then I suggest you are a layman and probably shouldn't be reading this anyway.

Common 3 Wire 3-Phase

Actually, this is the same as 4 wire 3-phase, and is actually used to describe how the wiring is done. The same voltages and types of service are still available, and is normally only done when the lowest voltage is not required, or for high-voltage 3-phase at 440V and above. For clarity, it is mentioned here, but to understand how it works, see the diagram and details for 4 wire 3-phase.

Common 4 Wire 3-Phase

The leads marked L1, L2, and L3 are hot leads, or "line," and typically, diagrams and schematics will continue to use the numbers, but change the letters to "S" for them after a switch. Sometimes, "M" is used to identify motor leads. "N" is neutral, and is never switched for this type of 3-phase service. Which is which? Actually, it is impossible to really know which is L1, L2, and L3, so we just pick out the three hot leads and start from there. Later, I'll explain how to wire these to a motor so the motor works properly.

The magic starts here! Let's say you check and find that you have 220V 3-phase service. Now, you can get three separate, single-phase 110V circuits by using L1 & N, L2 & N, or L3 & N. Also, you have three separate, two-wire 220V circuits by using L1 & L2, L1 & L3, or L2 & L3. For 3-phase, 220V, you need to use all three leads, L1, L2, and L3. Remember that you can't just decide to use a particular type of power because you want to — the device must be designed to work the way you hook it up.

At higher voltages, such as 440V 3-phase, the neutral (N) lead may not be provided, or a separate leads may be supplied for providing a 110V circuit.

A special type of 4 wire 3-phase service for 208V is available, too. This is accomplished in a strange way, and is most often used in lighting circuits where 208V two-wire and 3-phase service is desired, along with 110V service. It is less common, but may be found in older buildings and for special applications.

3 Wire w/Grounded Hot Leg is an older type of service. Sometimes, this is provided with 4 wires, so that 110V service can also be provided. This type of service is especially hard to test for, since most folks are not familiar with it. Normally, you have to check for voltage to ground, and the grounded leg will not show any voltage when a meter is used to check from the ground leg to ground. However, this lead can only be used for 3-phase, or a short to ground may occur. Otherwise, this service works like other 3-phase service

[byron3]

You may find this interesting =>


Voltage

Generally speaking, if you are in a residential setting your electrical service will be 240 volts. Industrial building and schools are usually wired for 208 volt service. Your kiln should be matched to the correct voltage.

Most electric kilns are wired for 240 volt or 208 volt power systems. Test kilns may be wired for 120 volts; if so, they will be compatible to either 208 volt or 240 volt system.

Electric kiln heating elements are rated for either 240 or 208 volts. Too much fluctuation (as in power reduction of your electrical service during peak usage hours) adversely effects the kiln's ability to reach temperature and also shortens the life of the heating elements. (http://pottery.about.com/od/potterykilns/tp/eleckiln.htm)

As for the % of amperage pulled by a circuit, according to NFPA circuits and breakers are rated for a continuous load of no more than 80% of capacity. 12 gauge wire and a 20 amp breaker would be designed to carry no than 16 continuous amps.

*above article is URL for source*

[Greymatter Glass]

ok I'm latr to my shop... but 2 things:

1. there's no such thing as "2 phase" or "double phase" there's single and triple. At least in the US. I'm not as familiar with grids and generating capacities in other regions of the world...but I've never heard of a 2 phase westinghouse, ge, ABB, etc generator...


2: 240V kiln run on 208v is just fine. All technical aspects aside, as long as you have 208v across the 2 blades you'll be fine... resistive appliances aren't as complicated as capacitive loads. If you're running a critical data system, hospital/medical appliances, or something like that you MIGHT want a 1:1 transformer for isolation, but you do not need a step up for 208 to 240 in a resistive load.

3: If you have the flow and someone local to do it, rewire your kiln for 3 phase... problem turned improvement.

[Rowdy]

Yo Greymatter excuse me single phase, it's been a few years since I last worked and for laymans it's better for someone to understand you have two hots compared to three.

Thank you Stroker for your great run down of three phase power for the folks to understand. I too worked over 10 years in the industrial electrical field and only want to see folks not get hurt. It's easy to do when jumping from residential electrical compared to 3 phase, 208 wild legs are nothing to mess with.

[Greymatter Glass]

Single phase: 1 hot
Triple phase: 2 hots

[Rowdy]

3 phase you have three hots.

Brown, orange, yellow. These are the three color representations of the three phases. You must have these three in rotation to run any type of motor. I have witnessed a 3 phase system go phase to phase and the resulting fireball was huge and injured 4 former electricians. All I'm trying to do is not get people or their equipment burnt to a crisp. Shall we continue on this discussion cause it sounds like you don't have much of a clue with electrical and I'm starting to worry about the information your are spreading.

[byron3]

3 phase you have three hots.

Brown, orange, yellow. These are the three color representations of the three phases.................... Shall we continue on this discussion cause it sounds like you don't have much of a clue with electrical and I'm starting to worry about the information your are spreading.

????



http://www.3phasepower.org/3phasewiring.htm (http://www.3phasepower.org/3phasewiring.htm)

The 3 phases are typically indicated visually in electrical diagrams by colors. The standards for these colors vary by country ......................

Conductors of a 3 phase system are usually marked by color code, to allow for balanced loading and to assure the correct phase rotation for 3 phase induction motors. Colors used vary widely and may adhere to old standards or to no standard at all, and sometimes vary even within an installation. However, the current National Electrical Code (2005) does not require color identification of conductors other than that of the neutral (white or white with a color stripe), the ground (green or green with a yellow stripe), or in the case of a High Leg Delta system, the High Leg must be identified with orange.

North America :

L1 = Black

L2 = Red

L3 = Blue

White = Neutral

Green = Ground



North America (newer 277/480 installations) :

Brown = L1

Orange = L2

Yellow = L3

White = Neutral

Green = Ground

[Rowdy]

Not sure what your questioning but your dead on there holmes!

[Cornbread]

if you don't plan on moving...can't the manufacturer just set your kiln up for 208? i was told paragon will do that. infact, i bought a 120V kiln and they asked for my zip code so they could find out exactly what voltage to set it up for. like 110 or 115 or 120 or 125...etc...you get it. just call and ask. it never hurts.

[Bryan]

follow up... got the 240 kiln and it works just fine on the 208

[Bo Diddles]

Yay!