Adding Kiln sitter to Bartlett controlled kiln

[jordan mcd]

Hi  - does anyone have links to instructions on adding a kiln sitter to a kiln that has a computer controller? 

I've tried fussing around with cone-offsets on my kiln but it's firing slowly and erroring off (E-1). The cones inside the kiln indicate a complete cone 6 firing, so I'd rather just have the sitter trip than the kiln just stall out and rely on the computer. 

I hope it's a relatively straight forward adjustment. 

Any help would be great - thanks. 

[neilestrick]

Run the power to the the Sitter, then on to the relays and controller system. You'll need a Sitter and a mounting box for it like THIS, which you connect to the controller box via a section of conduit. You'll need to move the power cord over to the sitter box. The hole where the power cord was is where you can attach the conduit. You can either run it by setting the controller to a higher cone than the Sitter and letting the Sitter shut it off, or put a higher cone in the Sitter and having it be a safety backup in the event of the digital system over-firing.

It would be good to figure out why the kiln is firing slowly and giving an error code, though.

[jordan mcd]

Thanks Neil - I've gone to extraordinary lengths to figure it out. The kiln shuts off after 13 hours- I changed out the elements from Olympic 2518 42 Amp/240 V (Max cone 10) to Olympic 2518 35 Amp/240V (max cone 8) because my kiln runs off a 50 amp service. 

Prior to changing elements the kiln would fire to cone 6 (pretty full load) after 12 hours. Now it bisque fires perfectly but just will not fire to cone 6. 

I could buy a used Olympic 2018 (slightly smaller 35a 240v) for $1900 but I think I'd just be repeating the same problem. 

[Bill Kielb]

2 hours ago, jordan mcd said:

Prior to changing elements the kiln would fire to cone 6 (pretty full load) after 12 hours. Now it bisque fires perfectly but just will not fire to cone 6. 

You just don’t have enough power to offset the load and losses. Smaller kiln or improve the insulation of the existing  kiln. Improving is difficult on an already built kiln.

Bartlett controllers don’t start erroring out till about 25 degrees per hour so even with a sitter this may become problematic in the final looks of the glazes. Some glazes just don’t like the super extended  firings.  Absent a decent way to insulate and given your power limitation, your  only practical recourse might be a smaller kiln with less surface area for losses.

[neilestrick]

3 hours ago, jordan mcd said:

Thanks Neil - I've gone to extraordinary lengths to figure it out. The kiln shuts off after 13 hours- I changed out the elements from Olympic 2518 42 Amp/240 V (Max cone 10) to Olympic 2518 35 Amp/240V (max cone 8) because my kiln runs off a 50 amp service. 

Ah yes now I remember. At 42 amps that kiln was not really a cone 10 kiln, more like cone 8 at best. At 35 amps it's definitely not a cone 8 kiln. You simply aren't pulling enough wattage to make it to cone 6 efficiently. Your kiln is 8.8 cubic feet, the 2018 you mention is 5.5 cubic feet. They both draw 35 amps and the smaller one is listed as a cone 8 kiln. Yours will get to cone 6 eventually, but the controller gets mad that it's going so slowly, and it's an expensive firing since it's running at full power for so long. The other problem is that once your elements wear even a little bit it's not going to get to cone 6 at all. You'll likely be changing out the elements every 30-50 firings, which is an expensive way to run a kiln. With a cone 8 model the element life will be better but still not great, about 75-90 firings. With a cone 10 kiln it'll be 130-150 firings.

I find that Olympic kilns are on the low end of power for their size. For example, the 2018 is 5.5 cubic feet. An L&L e23M-3 or Skutt KM1022-3 is also 5.5 cubic feet. The Olympic pulls 36 amps, the L&L and Skutt pull 48 amps. Plus the Olympic is going to have a lot more heat loss since it's an oval with a lot of surface area on the lid and floor.

[jordan mcd]

I’m just so frustrated with Olympic, spending so much time and money on this. They think it can get to cone 6 in six hours. 
 

the kiln I’m speaking of that’s for sale has elements for a kiln that it seems isn’t in production anymore 2018HT which draws 41 amps. Am I nuts to connect that to my 50 amp service? 

[jordan mcd]

Just to clarify- I was thinking of changing the elements to the 35amp 2018 kiln to fit my service. What’s in now are new 41amp elements 

[neilestrick]

4 hours ago, jordan mcd said:

Just to clarify- I was thinking of changing the elements to the 35amp 2018 kiln to fit my service. What’s in now are new 41amp elements 

At 41 amps it would run on a 50 amp service, however it would technically need a 60 amp breaker to be up to code. 

I think if you really want to be able to fire to cone 6 easily you should look at something like the L&L e23S-3 or equivalent (23 wide by 18 tall). It pulls 39.4 amps on 240V 1P service so it'll run on a 50 amp breaker, and is rated to cone 10. It's only 4.4 cubic feet, so half the size of what you currently have, but that's the size of kiln you're going to get if you want it to have the power to fire to cone 6 with good element life.

[jordan mcd]

I suppose I’ll do that, or go back to the old 42 amp setup on my 2518. I have a new 1.5 cubic foot kiln (13a 240v) I use to fire small work and pots- that gets to cone 6 in 4 hours. I’ll reserve the larger kiln for bisque and glazing larger work for now. 

Thanks once again.