Wired

[offcntr]

So last year I purchased a new kiln. Well, an old, used, but very well maintained kiln, a Skutt KM 1227 electric (twelve-sided, 27 inches deep) to replace my well-worn, also used Olympic of the same dimensions.

The Skutt is computer-controlled, which is a huge improvement, as it means I can program it to fire itself at a safe, measured pace, with holding time built in to drive out excess moisture if need be, and just walk away. Go to Saturday Market. Go to bed. The kiln turns itself up, and eventually, turns itself off.

Except when it doesn't. A few times over winter, the breaker would trip, and I'd come back to find the kiln blacked out and cooling down. I'd generally reset the breaker, grumbling under my breath, and start the firing over.

Last weekend, the breaker tripped twice. No idea how close to fired we came, as the power failure wipes the computer memory. The pots look pink, but feel a little... clunky. At least a few cones under-fired.

I spent Memorial Day afternoon unscrewing the connection box on the wall, looking for shorts. Opening up the control panel, likewise. Nothing obvious jumped out at me, though I did spend some extra time redoing the connections I'd had to undo when I installed the new (new, not used) Envirovent, as I'd realize the conductors would fit better in the buss block if I didn't twist the wires.

I'd closed up the control box and just about given up when I noticed that the model info panel read KM-1227-PK. 240 volt, 1-phase, 60 amp.

Wait, what?

Apparently, I got a better deal on this kiln than I realized. The PK is short for Production Kiln, the top-of-the line, cone 10-capable Skutt model. The Rolls Royce of studio electric kilns. Woot!

Except.

My old Olympic was a 48 amp kiln. The other 1227's I knew from Club Mud, both the old kiln sitter model and our new computer-driven version are both 48 amp kilns. You want 25% over capacity, so when I wired in the kiln, I installed a 60 amp breaker. Now, running a 60 amp kiln on a 60 amp breaker, there's no room for error. The tiniest power surge, and pop! goes the weasel. I talked to Perry at Skutt tech support this morning, and he told me I needed an 80 amp breaker. I'd also have to upgrade the wires, from 6 AWG to 4 (wire gauge, like sheet metal, gets bigger the smaller the number).

So I took a run out to Jerry's this afternoon, had them cut 12-foot lengths of no. 4 conductor--black, white, green--then found out they didn't have 80-amp breakers in my box's style, just 70 and 90. I worry 70 might keep tripping, and I don't want to go to 90, as I don't feel it's safe. The whole point of a circuit breaker is to trip when dangerously high current is running; I don't want the wiring to go before the breaker.

So I spent the evening wrestling fat wires through a skinny conduit, connecting the kiln end and the ground, leaving the remaining two leads hanging until I can swing by the electrical supply tomorrow after the Club Mud meeting.

So I can finally finish that bisque. Third time's the charm?

Comments

[danthered]

If it weren't for the fact you're using breakers, I could well and truly say your new kiln's been refused.

Also, I have a question: if you were to craft a Homarus americanus, then fire it just once, would it be…

…a lobster bisque?

[Error: Irreparable invalid markup ('<ducking,>') in entry. Owner must fix manually. Raw contents below.]

If it weren't for the fact you're using breakers, I could well and truly say your new kiln's been refused.

Also, I have a question: if you were to craft a <i>Homarus americanus</i>, then fire it just once, would it be…

…a lobster bisque?

<ducking, running, hooting>