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Bill Kielb

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Everything posted by Bill Kielb

  1. Thinking in terms of wattage, the center series group is likely close in wattage to top and bottom so maybe 2500 w which means 11 amps so both centers likely could go on a single relay. If not, add a relay and parallel feed the relay coils as zone 2. It’s very likely all possible Just need to know the real values of everything to figure out the best way though.
  2. Looks like that has been wearing for some time actually. My guess is you cannot screen it out because it is likely too small, but sieve likely won’t hurt. I think I would fire a few glazed test tiles (potential contaminated clay and glaze) to confirm if there is any effect. My guess, probably little to no effect. Maybe time for a stainless mixer. If this is your glaze recipe and your third party is only supplying dry mix, you might want to just mix your own. It’s fairly easy and probably a bunch more economical.
  3. Looks nice. If you have not already done so, the fan traditionally would be at bottom (to get the coolest air) blowing in to pressurize as practical to maximize heat transfer. Passive cooling is usually desired for maintenance and longevity but the fan ought to do a nice job. Looks nice and tidy. Is the controller a pid module (off the shelf temperature controller)?
  4. Probably a good idea to find a way to ensure they are never used as serving bowls.
  5. Many have tried and my understanding is the COE is so different the glass will crack and separate. Of course bowls being bowls many frown upon it as too risky.
  6. I think a redesign is in order for sure. All those solutions above work BTW. I think I would go with three control relays and break both phases as typical across each relay, works in any country in the future.. Preferable distribution would be top, middle, bottom so three zone control would be possible. Would need to know resistance or wattage of the elements though. As far as a safety contactor It’s an easy add if desired. I have a very economical source for 24 vac 60 amp rated resistive dp contactors, they are common in HVAC? In any event, the existing voltage, and phasing must be determined as well as the element resistance in order for a decent design to be created. one thing for sure, I would label everything permanently when done. Decent planning up front makes this project very doable.
  7. Yep. Looks like an early non standard design. I should correct that, single phase 240, you could make T2 the neutral (Not USA 240) so this actually would be fine. Just label L2 Nuetral. Further correction, L2 is fused for the control transformer so it needs work to make safe.
  8. It looks like he gave you the wiring diagram for the 240v single phase retrofit. Are you good with it or have someone who can do the work? Interesting in the diagram, T1 is the only switched lead, T2 is always hot. They likely don’t let them build it this way anymore.
  9. If I could give you multiple likes I would! Thanks for sharing. This has affected many folks over the years.
  10. So is it likely that both the new and the (rewired) old kiln could share an (installed to code) NEMA 6-50R socket? Yes, North America codes are pretty similar so in the end at 240v assuming 10k+ wattage, will likely be fine on 50 amp outlet and likely 60 amp breaker. The rule here protects the breaker from overheating under continuous load, hence the 25% over rating which is actually consistent (reciprocal) of the never load a breaker greater than 80% of its rating rule. The US has split phase 240v, so a bit odd with respect to the rest of the world but most of our household loads are 120v. It’s the old higher amperage vs higher potential safety argument. Split phase in general is more expense, wire etc…. Either way, she will need to rewire both and if they are nearly identical in wattage then sequentially share a code compliant branch circuit. If concurrent ops are needed, then another branch, another receptacle ….. Good catch though, may explain a lot.
  11. Yes, good catch, this kiln was built for 3 phase operation so the plug and wire size are fine for that operation. Needs to be re elemented and rewired to operate at 240v
  12. Might help finding off : You really ought to feel the off detent where the low point of the cam is. Even if the on/off contacts are stuck together so it stays on 100%. The low spot on the cam should be the only place it’s intended to turn off and you ought to be able to feel this flat spot. Common infinite switch shaft shape is an H shaft I believe to try and avoid this very issue.
  13. I am thinking not as the kiln is marked 48/1 which usually means 48 amps single phase. But your theory would be a reason why a 30 amp plug was used and …….. why now when it’s plugged in to a single phase source not all the elements work. All the more reason to sort out how it was actually wired in the past and will the OP need to change the elements to 240v and wire as single phase. Something I would expect an electrician to determine first and foremost, but kilns and electricians not necessarily a good mix.
  14. Yes, 208 v elements says get this straightened out. 208 v elements will draw significantly more amperage at 240v. Definitely get the diagram and you will need to check several things including if the original elements are still in there. Likely some work to make this fit your situation but doable.
  15. I think for a quick reasonable approximation and assuming the solution of glaze materials and water does not significantly change the unit volume, (which I think is reasonable). I would measure out 100 ml of the mixed glaze and weigh it. Knowing 100 ml of water weighs 100 grams the remaining weight would be that of the glaze materials. So let’s say it weighs 150 grams. Then a reasonable approximation would likely be 50 grams of glaze material is in that size sample. So scaling up, for every 200 ml of mixed glaze add 10g of your colorant to get close to the desired 10g of glaze to 100 g of glaze material. Test and see if you like the color. My thought is this is pretty simple and maybe more accurate than approximating what might have been added as water when the glaze was made. I think that’s workable………… anyone see a glaring issue with this?
  16. There is really no way that plug ought to be on that kiln. Your electrician should be able to wire correctly and safely so I would not trust the previous folks that wired that plug to it.. Not all electricians are savvy with kilns though, it’s not their mainstay, but when presented with such disparity they should realize the basic safety and code issues at hand. It sounds like you will need a kiln tech or at least someone who can confirm from the wiring diagram through the basic electrical and code requirements.
  17. This may help for reference. I am posting because three phase 240v service (High leg) is old but presents some special risks when working around it, plus a floating neutral. Anyway maybe good for reference and safety. Hopefully your old building contained a single phase service, then a three phase 4 w addition later. The last two diagrams are most common.
  18. Might line up some way, either perpendicular or parallel. Definitely not arbitrary. Neil makes a good point, if the pilot light is not connected to the switch, it will only indicate what is powering it. The inside of this switch typically looks like below which provides a spot to turn off the power. Most devices that use these have a need to be able to go full off. Might be just so worn though that it won’t anymore.
  19. May be just be a bit too worn, most infinite switches have an off location and detent where the switch wants to stop, your pilot light ought to extinguish as it passes through the off location if set up to indicate from the pilot output of the switch.
  20. Kiln wash should not melt or burn so if the wash is burning then , it is not kilnwash. Too much wax definitely could be an issue and will burn up and disappear along with the carbon stain by about 800 degrees. Can’t say I have ever seen that much wax used, but definitely possible. At 1900 degrees I think it unlikely to be the wax that is burning.
  21. Makes sense. When your new line drawn on the switch is at 12:00 is the kiln off? If so, then it appears you indexed it correctly with your line.
  22. Just a suggestion, if you limit the size of the attachment points of your control box you will reduce how much heat is conducted. Anything that limits the contact area and creates a space for air is very effective at reducing the conductance. If your control box has a continuous attachment tab on both sides, stand-off with washer or dimple in the metal is old school very effective and simple. Additionally the Element plane / control plane shield or separation is fairly standard now. Usually perforated top and bottom to allow air to rise and vent naturally. Also very effective.
  23. Interesting, fairly rare as the transformer winds are very different and cost to install both usually very pricey. Good to know though.
  24. Most schools would have three phase 120/208 which would be 208v L-L. Just asking, they had single phase service? Might be a reason for the 228 v measurement. Anyway, just mentioning in case it has future value.
  25. It’s been my experience that this is difficult to do and often not worth the effort: Once things are bone dry it’s really hard to successfully fix because anything you put in the crack will dry and shrink. For me it has been rare to have success at this especially through a glaze firing. Usually I just recreate the piece and try and do a better job compressing whatever cracked to begin with. If it’s ware for sale or even a gift and functional, I’ll just recreate. It won’t be as strong as not cracked in my experience. If it’s non functional, then patch as best you can compressing as much as possible reducing the crack to nothing at the bone dry stage. It may take several attempts to fill, compressing the new clay in the void as much as practical realizing the clay will shrink each and every time it drys. Likely you will still need bisque fix as a smaller version of the crack appears after bisque firing and finally maybe fill with glaze if you are lucky and this ends up non functional for personal use only. If so, post firing techniques such as epoxy, etc…. Can salvage the piece for personal use.
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