Bill Kielb

Nice work! Just to pass along if you ever find the need, heatsink USA was always a good resource for low cost heatsinks of decent size. Always have been able to design these to run in 90 degree ambient - no fan but takes a bit of heatsink to do it while not breaking the bank.

Those appear to be pre cut birch plywood circles. Have you used birch?

You might want to pick an original wattage to match and establish the new resistance to the original design using his current operating voltage. This way he will have the amount of designed heating energy available. When electric kilns wear by about 10% they usually have trouble making top temperature. In this case since this is a very small kiln electrical and load, bumping this to 4000 watts likely has no effect on his current wire and breaker and could provide additional room for future wear. Just a thought.

Suggestion: if everything is in order for the next test fire, your FTL or firing too long error implies that the kiln was not able to make 27 degrees per hour rate which implies not enough thermal power. So if everything is in order and you can measure actual voltage AND amperage while it is running that will reveal if in fact it has the power designed. Excess voltage drop will show up when a circuit is loaded up and the amperage will tell just how much power the kiln is able to deliver. Really good data to know but best known while operating. It would be good to check the deviation temperature set TeDe - pg. 24, default is 100f. Thermocouple is set to match type: R,S,K… also record the total time taken. It typically will be approximately 8 - 12 hours. and your final segment or last 200f of the firing is 100-108 f per hour to match the Orton cone chart. Many kilns, just make this rate at very top temperatures when new, so 140f for the last segment (last 200f) aligns more with a fast firing schedule than slow. The last 200f is where the major reactions occur or there is enough energy for the flux, silica and alumina to melt. The last 200f - 250f is really the most important part from a predictable heatwork respect. All those measurements should tell the story

Aside from reasonable rigidity (mechanical rigidity, very important), uncompressed fiber is a really really easy way to improve performance. Inches of thickness in fiber is everything in reducing thermal losses.

I also have a sneaky suspicion that like training in many sports, centering involves training your Central Nervous System a bit. I speed train for specific things and even though eligible to retire, certain speeds have increased even more so than when I was younger. In CNS terms it is not something you specifically feel but simply the repetition of swinging as fast as you can often helps things speed up a bunch. Interestingly some days better than others but definitely a way to trend upward in speed. Runners, running downhill, golfers, swing as fast as you can with something that tells you the speed of each swing. Centering is such an initial mystery for most with good days and bad days that until one centers a whole bunch - successfully - it’s hard to perceive you are improving. I do believe that after many successes your CNS, perception, dexterity has improved to a point where everything works so much better from visual perception to tactile perception to your muscles firing as needed to control your actions, practice is just necessary. I think if you do not have structural or outright mechanical issues, significant equipment or clay issues, repetition of something that works is likely one of the essentials for most folks learning to center. Develop good practice, start small and practice practice practice. I would submit for those new - often it’s not you, it’s training your central nervous system to play nice during the process. We don’t have CNS barbells, so successful repetition is likely the choice. Eliminate the obvious equipment / clay / mechanical issues, but once eliminated train like the pros.

Still working, how did everything go?

It seems to have worked here. Maybe reset your equipment

I wouldn’t over think it. Refires are hard on pots as virtually all fluxed reactions have already occurred in the first firing, except for the new applied glaze of course. My expectations for refires are low and if I can downfire then my chances of survival are better in my experience.

Although not easier, real quality pin stripe tape is my go to for a super high quality edge. 1/8” gets me any radius / shape I want as well. Costly and time consuming, but old habits are ……… proven for when I want it perfect.

Sorry to hear about the difficulty but it does sound like your thermocouple setting / type/ polarity may not match the controller. Also there may be default settings that could be an issue. Why doesn’t your new thermocouple match, is t the right one, right type? Before all is lost, I would suggest looking at ALL the factory settings and making sure they match your kiln, your thermocouple, it’s polarity, etc….. Relays can change form over time, so ensuring the coil is still the coil, the no and nc contacts are still functioning as intended also important. The relay in this kiln is super standard, are you sure yours matches electrically? The voltage for this kiln is 240 v 3 wire so L1, L2 and a ground in North America (No Neutral). The kiln needs to be on a 2 pole breaker, 20 amps. Do you have the wiring diagram and are sure the new parts are installed and match the function of the diagram. The new elements have to be installed in series as shown in the diagram. Your kiln is fairly small so easy to trace these faults logically. Still the DTC 100:is fairly old, things don’t last forever. some documents that might help Tnf 66 diagram https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/WTNF66.pdf DTC 100 manual https://eadn-wc04-7751283.nxedge.io/wp-content/uploads/DTC100.pdf Can you post pictures of old / new thermocouple and relay as well as the kiln equipment tag.

How much of that is water? Maybe not a bunch…..

If I read the Mayco literature it seems to say cone 10 performance may be noted on the bottle. Also as I go through the website and chips they seem to be noted as fired cone 6 oxidation. Cones definitely would help. A 30 minute soak at the end likely drives things to the next one or two cones higher. Check the labels on the bottle for special notes on cone 10 firing.

You should be able to call or order from Paragon https://www.paragonkilns.com/

Have only seen remaining in a handful of old houses — all fabric and rubber covered and interestingly only left in the attic and not replaced. Asbestos was used for a bit with the fabric covering for sure. Another great feature. Growing up, I think I remember seeing a can of this or two. Heck when I was eighteen I can remember tearing off a big piece of asbestos paper to protect against welding splatter.

While true, the thermal rating of the wire cloth covering was rated considerably less than todays thermoplastic covered wiring. Also probably helped make ungrounded circuits acceptable or the norm in a way. Not much good about it other than it could be cooled in free air but also free to start a fire under fault.

I agree, if they talk about SCCR Short circuit current ratings then they have a better understanding how things are ultimately rated. If the manufactures design has been certified, then their engineering has established it. It’s a 48 amp load so a 50 amp cord seems perfectly logical and the default short circuit current rating of the cord / plug is likely very much higher than 50 or even 60 amps at 240 volts dead short. UL 508A table SB 4.1 for power outlets is partially what you are looking for, except the ratings are in ka or thousands of amps over a time period. It’s far more complicated to get everything approved and to work safely so the engineering and certifications are the best values. some fun reading page 14: https://www.overcurrentprotection.org/wp-content/uploads/2021/08/Review-of-SCCR-and-NEC-2020-Presentation.pdf Still sometimes folks just have their own idea. I have been waiting for two months for a part time electrical inspector of one of our local villages to allow tandem breakers in the panel I have shown above. I was trying to add 1 circuit actually.I finally said the delay is getting so costly I will just change all the panels to newer with more positions. Approve the drawings already! 20 new 100 amp panels, drywall retrofit, labor, lots of extra money paid ……. By the end user.

I think the simple answer is the breaker is sized per code which treats continuous loads differently than non continuous because of the potential for extra heating produced in the breaker. Most breakers under NEC are designed for max loading of 80% for the same reason. The cords are sized and derated appropriately for corded conductors that also produce more heat because they are molded into a cord. The next size up rule often influences the materials to build things and stay safely conservative. Electricians in the states should be used to using 80% breakers, yet often when it comes to kilns they want to put a 30 amp breaker on a 30 amp kiln. Go figure, you would think they would be looking not to exceed 80% of the value of the breaker they just purchased or 37.5 amps. (125% of 30 amps btw) Is it a weak point? I view it as a design criteria. In North America breakers are generally produced and sized at 80% for continuous loads but will trip at there published amperage. The sizing is very much about the heat produced and the life and safety of the breaker. 100% breakers can be purchased, they need to meet very stringent testing standards before they are designated 100%.and usually have to be enclosed in a minimum size enclosure for cooling. There are many skilled electricians who deal with this daily, still there are probably many more line electricians that likely don’t so for kilns it is often a challenge. So virtually any retail breaker one buys for the home is an 80% breaker meaning it was designed to be loaded at 80% capacity for a continuous load.

The rule actually is in place to protect the breaker from overheating. It’s actually pretty common for resistive loads that could draw maximum amperage for a certain period of time. 3 hours here - I think. Anyway, the practice is to oversize the breaker by a fixed amount to minimize the heating on it. The kiln still draws 48 amps so many electricians are just not familiar with a kiln load which is considered a continuous load and has a specific heating effect on circuit breakers. Most electricians are used to loading a breaker with no more than 80% of its rated load, which by the way 125% is the reciropcal of 0.80. The rules just make things a bit more goof proof …….. if you know them. A 50 amp plug on a 48 amp load is really not an issue. The confusing thing is it’s designed to protect a typical breaker in a typical enclosure from overheating and degrading over time for a very specific type of load. An electric kiln.

Yes, full electrification means removing all natural gas and still being able to heat, cool, cook, hot water, dry your clothes and not cost more than the combined prior gas and electric. So, the most common single family upgrade is 200 amps residential. We do add 15kw supplemental heat though (like a large kiln), just in case everything fails. That fits ok in 200 amps, not 100 amps though. Larger than that services are limited to commercial or farm use here. Single family generally tops out at 200 amps in the Midwest. I’ve done so many I can recite the kw loads in my sleep. Heat pump Water heater 4.5 kw element, 500 w heat pump , range, up to 10.6kw, heat pump 9.6 kw …….. yikes! I can say the new heat pumps are FAR more efficient than just 2-3 years ago. PS. Don’t forget the copper tracer to go along with the fiber so it can be found when it’s broken.

No worries, hope it works out for you. When your uncle looks at it, the top right relay can simply go away connecting the wire on 1 to 7 and 3 to 9. Just left it in untouched for simplicity. It could become a backup for relay on the left marked A should it ever wear out.

Adamah art studios puts on events. Been there - nice facility IMO https://www.adamahartstudio.org/

Thought I would add here re: tandem breakers. Just was out looking at some old 1970 panel installs and came across a panel that detailed in the diagram how many and where the tandem breakers could go. The answer for this panel - no more than 4 allowed and they need to be at the bottom of the panel. This is a 20 opening panel that can expand to 24 using tandem breakers. This is actually sort of common as manufactures try and place them in a spot with the most cooling (the bottom). In theory they could generate double the heat of a single breaker.

I hate to say this but my best idea would be shielded cable for the thermocouple lead. This is all very speculative as a relay is worn enough to create lots of arcing noise and the guess is the noise is getting into the thermocouple circuit. Almost all circuits have noise suppression built in on board to combat this. So if I had spare relays, I would swap them out just to see if I had a particularly noisy worn relay. (Even with a new controller) Even so, how to guard against our new relay contacts from wearing and causing issues in the future? Sort of a total random thing actually if true. The shielded cable is my lowest cost idea that all kilns could benefit from but are almost not necessary these days due to onboard filtering etc… This is really hard to figure out without some really good test equipment and as such is very speculative. If you have a spare relay, change it. Try and route your thermocouple leads as far away from high voltage wiring as possible to decouple potential noise sources. Good grounding always helpful, especially the circuit board ground, however that is developed. It might be one of the screws on the board that fastens the board to the metal case is corroded and is designed to be the ground but no longer is a good ground because of the corrosion.

Since they are sheathed, not really twistable but that definitely is a technique. Since a relay can wear to the point of generating obnoxious arc noise (No good way I can think of capturing without an oscilloscope or digitally some way) just pondering if there is an easy one stop sort of sure fire way to minimize for future likely occurrences.