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View Full Version : That's a Whoops - Damaged PID



wyrmzr
07-15-2016, 10:18 PM
A friend of mine got a newer model Lee 10 lb. casting pot, and decided he didn't like it. So, he ordered a 20 lb. pot instead.
At that point, I decided I'd wire up my PID to his pot, mostly because his was taller, and left me room for casting sinkers, as well as boolits. Well, I decided to short the wiring in the process of the transfer.
After blowing a breaker, then figuring out what I did wrong, I got it properly wired, but found my SSR was in the permanent ON position. Instead of settling in at 700F, it climbed to over 1050F and was still on its way up.
So, I replaced the SSR, but now, when I plug in the PID, the temp reading shows 165F on a cold pot. Checking the temp of my unheated lead, it's actually at 75F instead. Strangely, the PID still "works", but in order to get around 700F, I now have to turn the temp setting to 800F instead of 700F.
Lesson learned: make sure your wiring is right. I got lucky, insofar as the PID still being useful for now, but I'm going to assume that at some point, I'll be best off replacing it so I get a correct reading.

JonB_in_Glencoe
07-15-2016, 10:37 PM
There should be a parameter adjustment for temperature error.

The PID I use (model JTD612) has a parameter called "Temp sensor error correction coefficient" (symbol is PSb).

wyrmzr
07-15-2016, 10:41 PM
Hmm... I do remember seeing that. Time to break out the manual and see if I can adjust accordingly.

Walter Laich
07-16-2016, 11:54 AM
the numbers that are showing are really just reference numbers.
You can note the important one (at your hold temperature) and use that

I have a couple of PIDs that are metric (Cº) and know that 207ºC indicated is actually 400ºF which is where I bake my PC bullets.

wyrmzr
07-16-2016, 01:37 PM
Just fixed the problem. The PSB setting had been set at 89. That's the same code you use to access that menu, so I suspect I must have managed to accidentally punch that in after I was already in the menu area. Now it reads 77 cold.

JonB_in_Glencoe
07-16-2016, 03:43 PM
Just fixed the problem. The PSB setting had been set at 89. That's the same code you use to access that menu, so I suspect I must have managed to accidentally punch that in after I was already in the menu area. Now it reads 77 cold.
Good to hear it is your password code "Oops" and NOT a zap from incorrect wiring.

Walter Laich
07-16-2016, 05:52 PM
great! that was a cheap fix.