ChenowethArts Posted January 27, 2017 Report Share Posted January 27, 2017 I'm trying to help an old friend by long distance with her kiln set up and decided to toss this question to the more experienced here on the forum: The kiln is a Jen Ken 2431 208v three phase rewired to a single phase. It runs off 70 amp breaker with 6/2 wire (very short run to breaker box). Resistance on element wires is 11. Has programmable controller ...Orton "Auto Fire" model. This is a three stack and the electrician involved recommended disconnecting the top element/stack. Any thoughts/advice would be appreciated. Thanks, -Paul Link to comment Share on other sites More sharing options...
neilestrick Posted January 27, 2017 Report Share Posted January 27, 2017 So what exactly is the question? She's got 3 phase power but a single phase kiln? Link to comment Share on other sites More sharing options...
Mark C. Posted January 27, 2017 Report Share Posted January 27, 2017 Not sure there is question myself-I think its about the use of the top section?Why would you disconnect it is my question? Link to comment Share on other sites More sharing options...
oldlady Posted January 27, 2017 Report Share Posted January 27, 2017 jen ken is still around and available for questions. i think they are in lakeland, fl? Link to comment Share on other sites More sharing options...
neilestrick Posted January 27, 2017 Report Share Posted January 27, 2017 In general it's not a good idea to remove a ring from a kiln, because it totally changes the wattage-to-surface area ratio. For instance, in that Jen-Ken kiln the floor and lid make up 28% of the total surface area of the interior of the kiln. That means 28% of the kiln is areas that don't produce heat. If you take off the top ring, that changes to 40%. The elements are wound to account for each scenario, so the kiln may be underpowered if the top ring is removed. The big question, though, is why do they want to take off the top ring? If the kiln is single phase but the service is 3 phase, that's not a problem. You can use a 2 pole breaker in a 3 phase breaker box and wire it up as a single phase kiln. Link to comment Share on other sites More sharing options...
ChenowethArts Posted January 27, 2017 Author Report Share Posted January 27, 2017 @neilestrick Kiln was originally wired 3 phase and has been altered for single phase...but the electrician involved recommended NOT connecting the top element. The questions are: Why should the top element be disconnected? Is there some danger in connecting the top? And, ultimately...should she go ahead and wire the top element back in (against the advice of the electrician)? Yep...didn't make this post very clear. The question is about why/why-not include the top element. @oldlady Hey thanks! I will do some homework on that. I appreciate the help. -Paul Link to comment Share on other sites More sharing options...
neilestrick Posted January 27, 2017 Report Share Posted January 27, 2017 Without seeing the kiln and knowing what's going on, I hesitate to say do it or don't do it. 1. What was the electrician's reason for unhooking the top section? 2. When the kiln was converted from 3 phase to single, were the elements changed? Often the single and 3 phase elements are different for 208 volt kilns. 3. Has the amperage draw/breaker requirement been confirmed with Jen-Ken now that it is single phase? 4. Does she have 208 volt service? Link to comment Share on other sites More sharing options...
No Longer Member Posted January 27, 2017 Report Share Posted January 27, 2017 Sounds to me the best thing she can do is get a different kiln and electrician. My basic philosophy with stuff like that is: "If you have to ask how to do it, then you shouldn't be." Sounds like a pig and a poke (or is it "in a poke"?) situation. Like Neil said, hard to say anything other than nothing can really be said. Everything in this scenario gives me cause for pause. Rewired by who? Has it been tested to be single phase and function safely since conversion? Since when do regular residential electricians redesign kilns? Don't get me wrong, it's not that folks can't, but they normally don't and shouldn't from a liability standpoint. The only thing I can think of is possibly the circuit can't handle the kiln as-is. ..and then there are the elements like Neil stated earlier... Here are the specs from a very common kiln in both 208/3phase and 240/1phase. 208/3: Top/Bottom element 10.8 Ohms Middle element 5.5 Ohms 240/1 Top/Bottom element 14.5 Ohms Middle element 32.0 Ohms Keep in mind we are talking about the same exact kiln with only an electrical service difference. Has her elements been changed, if so by who? Too many variables in this situation for me to say anything as well other than maybe buy something that was designed from the start to work with what she has. I may create my own monsters, but there is no way I would ever do that for a customer. Why? Because I like my house.... Link to comment Share on other sites More sharing options...
augal Posted January 28, 2017 Report Share Posted January 28, 2017 Neil, I am the lady with the JenKen kiln . I tried to post yesterday but it got lost in the approval so i will try to explain the question and answer your questions. I have a model 2431 jenKen with programmable orton controller on it. this model is made as single phase 240 and as a three phase 208. I have the three phase and am in a residence with 240 single phase service. I contacted jenken and the engineer talked me through rewiring kiln for single phase, he looked at pictures of before and after i did as he instructed, both by phone and pictures he sent me and i sent him. He had me test the resistance on the element wires and told me what size wire and breaker to use and how to hook to junction box. He checked behind everything i did to see that i did what he said. he had me disconnect the top element and the question paul was asking for me is do i really have to leave it disconnected? logic tells me that would the controller not control how hot and how fast it got hot which was the reasoning for the disconnect... (how hot and how fast it got hot). he said it dropped the amp pull from around 67 to around 56. i have it on a 70 amp breaker, wired with 6/2 wire to juction box located near breaker box. it is a dedicated breaker. it is now a phase one kiln on a 240 service. Link to comment Share on other sites More sharing options...
No Longer Member Posted January 28, 2017 Report Share Posted January 28, 2017 logic tells me that would the controller not control how hot and how fast it got hot which was the reasoning for the disconnect... (how hot and how fast it got hot). he said it dropped the amp pull from around 67 to around 56. Looks like there may be a "does" missing b/w "controller" and "not". It sounds like maybe you believe the controller doesn't control the top ring. The controller governs all three rings regardless of phase, voltage or number of zones. It sounds more like he said to disconnect it to lower amperage draw to an amount that the circuit will handle. The problem with that is the service is supposed to conform to the kiln, not the kiln to the service. Rewiring from 3 to single phase is one thing, unhooking a ring just to lower draw is a completely different matter. While that does lower the overall draw, that doesn't change the amperage the remaining 208v/3ph elements will want and now be feed at 240v. ( that is if that model uses different elements for 208 and 240v) Factor in there now appears to be a completely dead zone at the top of the kiln makes me start to think that perhaps I misunderstood something you said. I can't see an engineer telling anyone to do that; (and I've studied and worked with some really dumb engineers.) I can see taking a ring out if the other elements are used for 240v but a can't see an entire top ring used as a blanking ring and still going to the cone it was designed for. That is without factoring in having to cut the box shorter. I must have read something wrong as none of this makes sense to me. EDIT: I will say from both a personal and professional standpoint, that if this were one of my regular service calls, I would politely decline and walk away. If Jenken signed off on whatever was done and the modifications that were made prior to my involvement; I would have nothing further to add or say. If they are ok with it; then that's on them. (That's nothing on you augal; I've just learned long ago when to walk away from something.) Did I mention that my spouse likes our house too? Rewired over the phone and doubled check over the internet; what could possibly go wrong? Link to comment Share on other sites More sharing options...
augal Posted January 28, 2017 Report Share Posted January 28, 2017 I think i respectfully withdraw my question. Clearly all it has done is create confusion. The wording in that particular sentence referenced was correct Thank you for your thoughts on the subject. Link to comment Share on other sites More sharing options...
Guest Posted January 28, 2017 Report Share Posted January 28, 2017 I think i respectfully withdraw my question. Clearly all it has done is create confusion. The wording in that particular sentence referenced was correct Thank you for your thoughts on the subject. Sorry. I would ask the electrician why he feels you need to remove the top element then ask JenKen for their thoughts Link to comment Share on other sites More sharing options...
No Longer Member Posted January 28, 2017 Report Share Posted January 28, 2017 Augal, I think you took it the wrong way. My point was that if they (Jenken) were ok with it, there is nothing I can do or say from any point to confirm or deny anything with the limited information given (and apparently my limited understanding of what was done as I can't see them saying what I think they said. From what I understand there is no electrician involved, just an engineer from Jenken, right?). My last statement was just a humorous restatement of what I already said; I tend to do that a lot. You and your questions are always welcome here. There are questions that do exist that I can't comment on due to professional and legal reasons, that's all. It had absolutely nothing to do with you and I apologize if it was perceived as anything other than humor. As long as you did what they said and they approved, then they are on the hook. As soon as you do something someone else says, that involves another party in liability and gives them a way out. Link to comment Share on other sites More sharing options...
augal Posted January 29, 2017 Report Share Posted January 29, 2017 Thank you both. i do understand liability of asking such hypothetical questions. The jen ken guy was suggesting unhook top element to reduce amps pulled .The circuit has a 70 amp breaker with appropriate wiring. Without the top element connected it pulls 56, with it it pulls 67, and he said it would heat up faster with the element connected. We just reasoned if the controller is ramp programmed to certain temperatures, at a certain speed, it should not matter. No harm, I understand the reluctance to answer what may be perceived as a loaded question. Thank you for responding. Also for peace of mind, two electrician friends checked behind me on the wiring of the kiln. I may be a girl, but my dad taught me well. I am a cautious DIY who gets the experts to check behind me whenIi am doing something that can be a problem. Blond, yes, stupid,no. lol Have a good rest of your weekend. Link to comment Share on other sites More sharing options...
Guest Posted January 29, 2017 Report Share Posted January 29, 2017 The circuit has a 70 amp breaker with appropriate wiring. Without the top element connected it pulls 56, with it it pulls 67 He's right, you would need a 90amp breaker and wiring to safely draw the full 67 amp. Link to comment Share on other sites More sharing options...
Mark C. Posted January 29, 2017 Report Share Posted January 29, 2017 Not sure if this has been mentioned but you need a 25%safety factor on the breaker so that 67 amps on the 70 amp is not ok-so the way I have this in my mind is you either take off the top section and it draws 56 amps which works on your 70 amp circuit. Or you could rewire that circuit with buffer wire and a 90 amp circuit and use the top section those seem to be the choices to me. If Jenken says to take the top ring off and its ok then its fine to do that. If you want the top ring then you need to add a 90 amp circuit your choice. Link to comment Share on other sites More sharing options...
augal Posted January 29, 2017 Report Share Posted January 29, 2017 thank you that answers the question. i can see that it cuts it too close. Link to comment Share on other sites More sharing options...
neilestrick Posted January 29, 2017 Report Share Posted January 29, 2017 Sorry for the late reply. I was out camping with my kids all weekend. In regards to your original question, no you can't hook up the top element if it will put the amperage draw at 67. That's too close to the 70 amp breaker, as mentioned above. When he says it will heat up faster with the top element connected, he means that it is now producing less heat. So even though the controller will compensate for that, it may be that at some point the elements won't keep up with the program and it will fire slower as a result. In regards to how odd this whole situation is (not your fault, by the way. Jen Ken has give you some very odd advice, IMO) I have a couple more questions. It troubles me that he would tell you to unhook an element, and it also troubles me that your kiln would pull 67 amps. That's enough power for an 11-12 cubic foot kiln. Is your kiln that big? 1. Did you change the elements when you rewired it, or did he have you leave the same elements in the kiln? That is, are you now running the original 208 volt elements on 240 volt service? 2. Is THIS your kiln? 3. What does the serial plate say the amperage should be at it's original 208 volt 3 phase configuration? Actually please tell me everything on the serial plate. Leaving an element unhooked is not the proper way to run a kiln, and the fact that he recommended that means that he didn't have you convert it the way it should have been done. I would just like to get to the bottom of this situation and make sure that your kiln is wired up and functioning to factory specs. If the link that I showed is indeed your kiln, a factory original 240V1P kiln should only pull 45 amps, so I'm not sure how he's got you up to 67 amps. Link to comment Share on other sites More sharing options...
augal Posted January 29, 2017 Report Share Posted January 29, 2017 I am sending the information to your email if that is ok Link to comment Share on other sites More sharing options...
augal Posted January 30, 2017 Report Share Posted January 30, 2017 neilestrick :this is what i sent. i agree it might help someone with the same issue. On the front plate is model af 2431 3†208v 45amp three phase. It has now been wired to one phase. The resistance on the element wire he had me test read 11 . the kiln is 31 across and 36 ½ tall. I am looking to see if I still have the photos before and after wiring I cleaned out photos and may have deleted them The 70 amp breaker is wired to a junction box with 16/2 wire. I understood that the elements were the same in this unit, they were not changed out and that did not seem to be a concern in the conversion. the man who helped me was very nice and he went above and beyond to help me. Yes it is my kiln in my shop at my residence. Link to comment Share on other sites More sharing options...
neilestrick Posted January 30, 2017 Report Share Posted January 30, 2017 Does it say how many watts on the serial plate? Link to comment Share on other sites More sharing options...
No Longer Member Posted January 30, 2017 Report Share Posted January 30, 2017 I understood that the elements were the same in this unit, they were not changed out and that did not seem to be a concern in the conversion. I would like to politely point out that unhooking the elements in the top ring didn't seem to be a concern either. Link to comment Share on other sites More sharing options...
augal Posted January 30, 2017 Report Share Posted January 30, 2017 Neil I cannot find watts anywhere on the plate i can give the serial number on it . I just found your reply sorry i was slow to respond Link to comment Share on other sites More sharing options...
neilestrick Posted January 30, 2017 Report Share Posted January 30, 2017 1.Can you confirm that THIS is your kiln? If not, can you find your kiln on the JenKen web site and post the link here? Link to comment Share on other sites More sharing options...
augal Posted January 30, 2017 Report Share Posted January 30, 2017 yes that is the kiln i have Link to comment Share on other sites More sharing options...
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