Lilith Rockett

I think the wiring is correct, correct gauge, also conduit and 100 amp circuit, all of it has been checked by Skutt techs, and the wiring from the box is how it comes from Skutt. It has worked fine for a decade like this as well and there is another 1231 next to it with no problems. Also, no heat on the wire or circuit during firing. The 3rd test is firing right now and is on target. The second test came out perfect like the first. It seems like it may be fixed, but still pretty mysterious as the thermocouples had already been changed and checked several times. But the goal is a functioning kiln, so I'll be happy with that. I'm bringing the replaced thermocouples and wires to Perry to have checked at Skutt. It will truly be baffling if they find nothing wrong with them. I'll just be happy to be able to fire work in the kiln rather than simulated loads and tests. It's been an expensive and time consuming 18 months for both me and Skutt. Thanks for thinking through this with me.

Yes, grounded.

Perry has confirmed that the amps are as they should be. I have not tested the resistance yet. I know that the elements are in the proper places as they were installed by a tech and looked over by 2 more. I have been wondering if there was some sort of contamination in the center elements that is causing this problem, which has been somewhat intermittent while also being consistent as it is the same intermittent problem for 18 months. Often I will make an adjustment (replace a part, like the relays, or thermocouples) and the first test will be normal, then the second firing will finish but have an anomaly that is easy to miss, then the third firing stalls. Sounds cursed, I know, but there must be a reason we just haven't been able to nail down. But, as I mentioned in a prior response, after changing t2 and t3 and their wires last night, the kiln fired perfectly. And now a second test is in progress and looks normal too, so far. T2 was a new thermocouple that was replaced with a different new one. T3 was not new but had functioned in each section with the same problem in the middle section. So it had been determined that it wasn't a problem. But now absolutely everything has been replaced at least once, so if it doesn't work it should be related to the elements and/or some sort of interference there, right?

I checked all of that and nothing is hot. Phew!

It is on a 100 amp circuit. Voltage is 240, not running high. I tested it throughout a firing once in each section. There is another KM1231PK right next to it firing perfectly with none of these problems (on it's own circuit, obviously).

I know they are type S, and I know the difference between type K and type S. I replaced t2 and t3 last night with brand new (type s) thermocouples and wires even though t2 had already been replaced a few months ago. Now everything is new. The test I did last night looked perfectly normal, cones dead on. I am repeating the test because the problem has been intermittent, making things more confusing. So far the temperatures are reading within a few degrees, so completely normal again. I'll check the logs tomorrow and if good likely start a third test, but I can test the resistance before starting the next test, just to know. There is another identical kiln right next to this one that has had none of these problems, although less identical now that the problem kiln has all new parts.

I apologize if I am not communicating properly here. I do not understand the + QUOTE box. Am I to respond there or here? I don't mean to make this more confusing than it already is. I have a Skutt KM-1231PK. 240v, single phase, cone 10, Type S thermocouples, APM elements. After replacing almost everything, and having several techs look at it, I now have a brand new box on it and new bus bars. The same thing happened in the next test (zone control cone 9 med)- it stalled at 2050 for 7+ hours. The t2 outs were at 100 from 400 degrees on and still could not keep up. There was up to an 80 degree difference between t2 and t1/t3, but no error code. The next test (not a test really but a single zone bisque I attempted) fired about 2 to 3 cones too hot. After that Perry gave me 2 more thermocouples and wires to change out t2 and t3. T3 was the only thing not yet changed. He thought it was a t2 problem, although that was a new thermocouple we had replaced before. Now absolutely everything on the kiln has been changed except for the elements. I am running another test now. I ran the manual diagnostics from the controller prior to starting. The amps are 28-23-28. There are many things that people have mentioned or suggested as possible problems that are beyond my technical understanding of how things are working. I have a more general understanding of the way it works and am mechanically adept enough to change out all the parts and troubleshoot the problem. But currents and duty cycles are not something I am familiar with. I can tell you that everything is new now. And that it worked fine for a decade until that last element change. Since then it has not worked. It has boggled the minds of everyone at Skutt, which is why I am reaching out to a wider audience. Perry absolutely does not think it could be the elements, but if everything else has been changed, what else could it be? I will take this to Perry tomorrow and see what he says. Plus, I'll know by tomorrow if the kiln stalls tonight. I'm not sure what more information to give you. I am willing to do any other tests, but would need to be told what and how. I have not tested the amps during a firing. only the voltage.

I've been working with Perry on this for 18 months now. I have changed out the controller 2x, changed out the relays, the thermocouples, the thermocouple wires inside the box and outside, the terminal strip, and now finally I have a brand new box on the kiln, essentially making it a new kiln, with the new bus bars and wires and solid state relays. I kept the touchpad controller so I can download the logs to analyze. The wiring from the box to the wall is new as well. the elements appear to be fine. I run manual diagnostics each firing to be sure. I tested the voltage while the kiln was firing every 15 minutes for a while to be sure I caught everything. (that was a little scary) Perry finds it hard to believe it could be the elements, but we may change out the center elements next to see if that does the trick. It is truly mysterious. We assumed the new box would solve the problem. No one can figure out the problem. Bartlett continues to think it's a thermocouple, but the unchanged T3 has been moved to each position with the same problem occurring. I do not usually get an error code, The kiln usually just starts lagging at T2 and eventually the kiln stays at some temp (usually 1500-2000) that it can't get past for hours until I shut it down. It will stall on both bisque or glaze firings. Also the outs at T2 go to 100 very early, around 300-400 and stay there for the duration. So even with the center section giving full 240v the whole time it does not keep up with the top and bottom. Everything is clean. The load is a consistent simulated load of kiln furniture every time. The cones are placed about 4 inches from the thermocouples and nothing else is interfering with them. Both Jim Skutt and Perry Peterson have gone over the kiln for hours and found nothing. That is why I am out here crowdsourcing, in case this anomaly has appeared somewhere else. There really is little else to change beside the elements, even if it seems impossible that they are the problem. It is a very confusing and frustrating situation. Any thoughts? and Thanks for thinking through this with me!

Thanks for your responses. I have a Skutt 1231 PK single phase, 240v, with type S thermocouples and APM elements. In single zone it will complete a firing, but it is a half cone difference, cooler in mid section, and fires too hot. (I know I can do an offset.) In zone control it is inconsistent and mostly stalls without an error code. It will fire to anywhere from 1530 -2050, stay for an unlimited time and never get any hotter, with up to an 80 degree difference between T2 and the top and bottom. The output for T2 locks on at 100 very early in the firing, sometimes around 300, and stays there the entire time without making much difference. T2 lags from 20-80 degrees. It has been looked over by 2 difference techs and Jim Skutt and I sent the logs to the engineer, and no one knows why this is happening. It all looks fine. The kiln worked fine for a decade and then this started after the last element change. Almost every part of the kiln has been changed out, and now finally I even have a whole new box on it to try to eliminate the issue. Sadly it made no difference. The only thing that hasn't changed is T3, but it has been tested in all positions , and the same thing happens, so it mustn't be that. The only thing I can think of is that there is some anomaly in the alloy that the elements are made of. They are from the batch that came after the supply chain shortage. The resistance is normal, so no one has believed it could be a problem. That is why I am reaching out here to see if anyone has heard of anything like this. There is a second 1231 PK right next to it running fine, so it is also not the building. Is there anything I might be overlooking? It has also had 3 controllers, and I download the logs from every firing to try to find the anomalies and see if I can detect how they are triggered. I hope someone out there can help! Thanks!

Has anyone had problems with their APM elements purchased after the supply chain shortage and being available again in July 2022? I use zone control and my center elements do not seem to be able to keep up, so the kiln continually stalls out, usually without an error code. Even in single zone the center section of my 1231 pk fires cooler than the top and bottom. I've replaced every part of the kiln and the problem still exists, so I am left only with the elements as the problem. The kiln worked fine for a decade, until this last element change. As I said, everything has been changed except the elements. Has anyone experienced anything like this? Any anomalies at all after an element change, whether single zone or zone control? I have spent 18 months troubleshooting this problem, and this is the last thing I can change.