Need everyones help on a PID problem

[Mr Walleye]

Wildcat

I agree with Pensrock, you gotta do what works. You really shouldn't have to run another auto tune if you wrote down your numbers. All you really have to do is adjust the cycle time and readjust the P, I & D numbers manually back to where it was working better.

It's interesting though, I run mine set to 0. I adjusted it there based on the information here on the forum. I believe it was BubbaGrump that indicated there wasn't any reason not to run it at 0 when used in conjunction with an SSR.

Mike

[Mr Walleye]

WildCat

According to the Auber manual the default/factory setting for the cycle time with an SSR is 2 and a relay is 4.

Mike

[Wildcat]

 ???  Relay?

[iceman]

ThermoWorks has a caculator for boiling water temps on it's main site.
Wildcat they also have the wire thermocouples I use for about 12 bucks. I'll get the part number for you when I get a few minutes later today. That will solve the grounding problem. Your turning into a PID expert!  :D ;)

[iceman]

???  Relay?

You have an SSR in yours. Not a mech relay.

[Wildcat]

ThermoWorks has a caculator for boiling water temps on it's main site.
Wildcat they also have the wire thermocouples I use for about 12 bucks. I'll get the part number for you when I get a few minutes later today. That will solve the grounding problem. Your turning into a PID expert!  :D ;)

:D Looooooooooong way from expert, but I am beginning to understand how to use this thing.  Even with a temp swing of +/- 2 degrees, it is much less of a swing than I get with the slider alone.  Good investment IMHO.  Use of the slider was easy, but required too much of my time on the long smokes.

[Mr Walleye]

Wildcat

Your Auber Controller is setup with an SSR (Solid State Relay). You can also set them up with a standard relay but they are subject to burning out if you cycle them too fast. The SSR has no moving parts and therefore it can be cycled at a much higher rate. This is correct to the best of my knowledge.

Mike

[Wildcat]

I just looked back on this thread.  The first time I went to adjust the cycle it was on 12 before I set it to 0.

[pensrock]

Mike that is correct. Mechanical power control relays will eventually cause the contacts to burn due to the opening and closing. The other thing to consider is the contacts inside the controller, if it also has mechanical contacts. I would think your controller works more like a triac output than a mechanical output, in other words an electronic output. I do not think I would ever set the cycles to 4 for a mechanical contactor, that's way to many on/off cycling. I think the Barber Colman and Honeywell instruments that we use default to a 20 or something close to that.

Wildcat, I would be very happy with a +-2 degree swing in temps. Thats nothing, your controller is probably only capable of +-5 degrees calibration and the probe can be as high as +- ten degrees. Two degrees is great, why sweat trying to get one more degree? It can change some due to the outside temp, the size of the load in the smoker, if the puck burner is on or off. There are a lot of variables to consider. Just because it is +-2 this load does not guarentee that it won't be +-1 or +-3 the next time. Anything within the calibration accuracy of the controller is very acceptable. You should look for another thermocouple so you do not need to worry about the tip touching anything though.

[Wildcat]

ThermoWorks has a caculator for boiling water temps on it's main site.
Wildcat they also have the wire thermocouples I use for about 12 bucks. I'll get the part number for you when I get a few minutes later today. That will solve the grounding problem. Your turning into a PID expert!  :D ;)

Thanks Pat

[Mr Walleye]

WildCat

If you look in your manual (on mine it's page 8 ) there is a chart that shows all the factory settings for all the settings on the controller. You can manually adjust any of them and if your not happy with it just set it back to what it was.

Mike

[Wildcat]

Thanks guys.  I am very pleased with a 5 degree swing (2 either side).  I will play with it a little and get the best I can, (you know - new toy syndrom) but where it is at is satisfactory.  I did notice during this last smoke that the closer it got to target meat temp, the greater the swing.  I did run the generator the whole time.

[pensrock]

That's why you want everything to be as close to an actual run when doing an autotune, because if you make a big change, it is not tuned to handle it. So if you autotuned empty and without the puckburner then tried to run a large load with the puck burner you would most likly see a differance in the way it controls.
Also if you adjust the numbers in the P-I-D settings manually, you should allow some time for the instrument to adjust itself to the new settings before making a judgement of how well its working. I would let it go for a good 15 minutes before deciding if I wanted to change it back or adjust it more.
Isn't this fun? LOL..... Tuning instruments requires lots and lots of liquid refreshment!

[iceman]

I'm heading to the commercial icemaker in the garage with a bottle of rum and cola as we speak!!! This one day off before going back up north is making me thirsty.

Widcat I think either the 363 or the 383 would work for you.
 
Wire Probes
Very inexpensive and can be used in destructive testing or where you need a small, fast sensor that can be shut in an oven door, threaded through a small port, taped down, screwed down or glued in a hole.




The maximum temperature listed for the probes applies to the sensor itself. Plastic handles and thermocouple plugs are rated for short term exposure of 482°F (250°C) and extended exposure of 428°F (220°C).


--------------------------------------------------------------------------------


Fine Gauge Wire Probe
PTFE insulated with exposed junction. Easily taped, clamped or glued to surfaces, in holes. Wire dia: 0.01", 0.024" with insulation. Very fast air, gas or general purpose. Max. Temp 482°F
113-362 39" length $12.00     
113-363 78" length $14.00     
113-365 10' length $16.00     

--------------------------------------------------------------------------------


High Temp Wire Probe
Fibreglass insulation with exposed junction. Use for ovens and appliance temps. Max. Temp 662°F
113-382 39" length $12.00     
113-383 78" length $14.00     
113-385 10' length $16.00     

--------------------------------------------------------------------------------


Heavy Duty Wire Probes
PTFE insulated with exposed junction. Stranded wire with less than 0.1" overall diameter. General purpose. Max. Temp 482°F
113-372 39" length $18.00     
113-373 78" length $22.00     
113-375 10' length $29.00     

[pensrock]

I think those would work well, just make sure the exposed tip of the sensor is not touching the metal surfaces. Since it is a wire T/C you should be able to twist it around a rack or something to hold it in place.