lynferr Posted August 12, 2018 Report Share Posted August 12, 2018 Hello everyone! I am new here and really hope someone can help me figure this out! I am having a huge kiln issue and thought you might be able to offer some advice. My kiln is suddenly underfiring. It's an old Gare/Evenheat with an ancient controller. It looks pristine, hardly used. I had it wired by an electrician, who at that time, checked the voltage and said it was good.I replaced the thermocouple about a year ago, it was the only thing that looked worn. No kiln sitter, but two firing modes (Cone-Fire mode and Ramp-Hold mode). I have been using the Cone-Fire mode, and it has been working well, shutting off on or near the programmed temp, witness cones looked good. It has suddenly started to shut off early, while the temp is too low, but it still says CPLT! The first time it happened, it was set for Cone 6 (2195 degrees on this controller), the medium speed (about 100 degrees an hour) with no hold. It said complete at 2000. The next firing, I did cone 6, medium speed, with 30 minute hold. at 1928 degrees, I got an ERR 1 message. It was a VERY hot humid day- electricity issues? I emptied the kiln, visually inspected the coils for burned spots, flattened areas- nothing. They look good! Then I switched it on to check the coils, all were glowing red. I reloaded and tried firing again, this time to cone 7 (2219 degrees), medium speed, no hold. 10 hours later, It was CPLT said 2196, but the witness cones didn't even begin to bend, even the 5. I am at a loss here. Not sure what to do next. I'm thinking about switching to the Ramp-Hold Mode next, but wonder if I should try one more time setting it to cone 8! Seems weird that the controller could be that far off all of a sudden. What would you suggest, short of getting a new kiln! (I wish..) Link to comment Share on other sites More sharing options...
lynferr Posted August 12, 2018 Author Report Share Posted August 12, 2018 The part that is most difficult for me to understand is why the digital controller is saying CPLT, thus shutting off the kiln, BEFORE it reaches the programmed temperature? Link to comment Share on other sites More sharing options...
Benzine Posted August 12, 2018 Report Share Posted August 12, 2018 I wish I could help you, but despite my heavy use of controller controlled kilns, I am not a troubleshooting expert. If Neil, this board's Moderator, doesn't respond, maybe send him a direct message. He is the person. who will have the answers. Link to comment Share on other sites More sharing options...
neilestrick Posted August 13, 2018 Report Share Posted August 13, 2018 I would first try replacing the thermocouple. That would be the simplest and most likely fix. Also make sure there are no loose thermocouple wire connections. Bad thermocouples can cause the controller to do odd things. Are you sure you're reading the final temp, and not the current temp? Link to comment Share on other sites More sharing options...
lynferr Posted August 16, 2018 Author Report Share Posted August 16, 2018 Yes, it is the final temp. Also, it was no longer reading the room temp at a complete cool, it was saying 145 when the room was 70, so, I had an aha moment and said- thermocouple. Ordered a new one. The thing is, it's not so old! 20 firings! The kiln is rated cone 8 max, and I've never fired above cone 6. Of course, I would feel better if it were rated for cone 10. But this is what I have, along with several ruined kiln loads full... Link to comment Share on other sites More sharing options...
lynferr Posted August 23, 2018 Author Report Share Posted August 23, 2018 OK, so I replaced the TC and the stone cold kiln is reading 365 degrees. Now what? Link to comment Share on other sites More sharing options...
neilestrick Posted August 23, 2018 Report Share Posted August 23, 2018 @lynferr Check that you don't have the two wires switched. Are you using a type K thermocouple? Is your controller set up for that type of thermocouple? Many controllers can use more than one type of thermocouple, and if you're on the wrong setting it won't read correctly. Link to comment Share on other sites More sharing options...
lynferr Posted August 23, 2018 Author Report Share Posted August 23, 2018 The wires are not switched, they are clearly marked. tey are not crossed. It is a PY81-4, type K TC, the same one that I purchased previously. There was a slight curve downward in the peak temp for the last 4 firings but on the last firing, the final temp was was 150 degrees off even though it said complete The final screen never went back to normal, and now with a new TC, it is saying 300-400 degrees in a room temp situation. If it is the controller, which I'm startng to think, for this 35 year old dtc 600c, is there a reasonable fix? I don't want to by a whole new controller, but a new board would work. Is it available for this controller? Where? I think Parsgon owns this particular controller now. All of the wiring looks clean, the board is the next logical suspect Link to comment Share on other sites More sharing options...
neilestrick Posted August 24, 2018 Report Share Posted August 24, 2018 3 hours ago, lynferr said: The wires are not switched, they are clearly marked. tey are not crossed. It is a PY81-4, type K TC, the same one that I purchased previously. There was a slight curve downward in the peak temp for the last 4 firings but on the last firing, the final temp was was 150 degrees off even though it said complete The final screen never went back to normal, and now with a new TC, it is saying 300-400 degrees in a room temp situation. If it is the controller, which I'm startng to think, for this 35 year old dtc 600c, is there a reasonable fix? I don't want to by a whole new controller, but a new board would work. Is it available for this controller? Where? I think Parsgon owns this particular controller now. All of the wiring looks clean, the board is the next logical suspect I'm thinking it's probably the controller, too. If everything else is good- tight connections, etc- then it's the likely culprit. Double check the wiring connections to the board. You can't buy the board without the touch pad. I'd go through Bartlett Instruments for the replacement. They generally have the best prices, and they're great people. Give them a call, they'll have some questions to make sure you get the correct replacement. Link to comment Share on other sites More sharing options...
Babs Posted August 24, 2018 Report Share Posted August 24, 2018 Do you have to select the correct thermocouple on the controller? I would get weird readings if I did not do this with a hand held digital pyrometer I had . Just saying Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.