Kiln install

[allfiredup]

I am installing 2 kilns in a separate room from the electrical box. I know that this kiln gets wired directly to the box but when I run my wire to the next room, what kind of switch do i need at the kilns if im hard wiring them to the box?
any help would be appreciated. Thanks
Phil

[Speedy Petey]

What is the amperage draw of the kilns?
Are they meant to be hard wired? A receptacle and plug are a form of disconnect.

If you need a disconnect switch, which one depends on the circuit size. Typically a "pull-out" type disconnect will work for anything up to 60 amps.

[HayZee518]

Normally kilns are 40 amp apiece. If you want remote disconnect means for each kiln, I'd put a non fused disconnect adjacent to each kiln. The kilns operate on 240 single phase. sometimes a kiln uses a timer for firing the "bisque." The timer is rated at 240 volts 40 amp with a 240 volt timer motor. Your primary overload device is the 40 amp 2 pole breaker feeding the circuit. Look at the nameplate and find out what the current draw is for each kiln and get back to us.

[Speedy Petey]

I've wired "hobby" kilns (residential) with anywhere from 30-60 amp circuits. It all depends on how big it is.

[allfiredup]

It draws 48 amps. I have it hard wired to a 60 amp breaker using 6 gauge wire and the kilns are directly in front of the box. The new set up is the kilns are in a differnt room but still within 50 feet of the box. Would I run a line from the breaker to the swich and connect the kiln to the wires at that swich.

[HayZee518]

Run a length of 6/3 armored cable to each disconnect. Use armored cable for mexhanical protection. You can nail the armored directly to your joist face. Romex is a no no unless you bore holes at approx center of the joist or provide running boards along your staple path. Use the armored from the disconnect to the terminal box of each kiln. Use "greenfield" connectors for the armored cable.

[allfiredup]

Ok, I just went into the new space again today. Im going to have to run more than 50 feet of wire. Do I need a higher gauge wire so I dont get power loss? Also I need to run this cord along a Brick wall and ceiling so dont I need to use a metal conduit for that cable you speak of? Thanks for the Help.

[HayZee518]

voltage drop doesn't come into play until 100 feet and then it's no more than a 3% voltage drop per one hundred feet increments. the armored cable is like a big bx cable. no, you don't need conduit for it. the metal braid is used for an equipment ground and mechanical protection. if you are nailing to the joist face use two hole greenfield straps.

[allfiredup]

if i cant get armourd cable and need to use standard cable can i use a flex aluminum conduit in a commercial business or do I need the sold steel conduit? Which is the code.

[HayZee518]

If a feeder comes in a manufactured cable set {greenfield} also called armored cable you can run it exposed as the metal jacket is the mechanical protection. if the jacket is aluminum flex its ok {doesn't have to be steel} most cables can be ordered through your local electrical jobber. I wouldn't depend too heavily on home depot or lowes to have ANY of it. If you need to run it in conduit, say pvc, you'll need to run three wires, equipment ground, and two hots. metal conduit again three wires two hots and a ground. from the conduit to the disconnect you'll use a flex greenfield with the same no of conductors but the flex cannot be longer than 6 feet. from the disconnect again three wires no longer than 6 ft. Pool connections are different, the flex {sealtite} cannot be longer than three feet.

[Speedy Petey]

if i cant get armourd cable and need to use standard cable can i use a flex aluminum conduit in a commercial business or do I need the sold steel conduit? Which is the code.

All I can say is your local codes will dictate this. Do you know the local codes???
I certainly hope so since this is a commercial space. In fact I seriously doubt it is legal for you to do this work in a commercial space. EVEN with the LL's permission. The liability is just to high to risk this, and I'd bet the local laws require some amount of liability insurance to do commercial work.

If you DO decide to go ahead and do it yourself I'd run conduit the whole way from panel to disconnect and use a flex whip to the kiln.


Just a few points to clarify.
- You CAN have longer than 6' sections of metal flex (FMC - flexible metallic conduit) as long as a ground is run inside, which should be standard practice anyway. NEC 348.60

- The only restriction for pools is a six foot limitation of liquidtite flex for outdoor spas. Pool lights have a similar limitation. NEC 680.42(A)(1)
Motor cords are limited to three feet.