PID Not Turning off Heating Element - Need Help

PID Not Turning off Heating Element - Need Help

What am I doing wrong? Bad SSR, Bad PID or Bad Process?

I just got my control panel up and running, but I'm having some problems with PID. It seems to keep heating regardless of the Set Value.
On brew day I set the PID to 160 F, but the temp kept rising. I ended up turning it off at around 185 F and letting it cool back down.

I did this one more time immediately after brewing and verified that the PID was not in manual mode. The SSR and Out light on the PID where synched and going on and off pretty frequently.

After brew day I made several attempts at running auto tune. I first went with Kal's recommendations of setting the temp for 154 and starting the auto tune at around 144.
During auto tune it sounds like the element never turns off. I ended up bailing when it got close to boil temps. I repeated this two additional times, both times at lower set value temps (120 F then 100 F). Both times the element sounded like it was on the entire time and I ended up stopping the auto tune just before boil.

Here's my setup:
Auber SYL-2352 PID controllers
Settings: Sn: = 21; FILT: = 5; At:=2; All other parameters set to default (verified with manual)

15 gallon kettle recirculating 7 gallons of water with lid on.
Currently, I don't have my HERMS coil installed so I am just recirculating by running out of the ball valve drain through the pump and back through the top inlet installed on my kettle lid. The temp probe is mounted on the side of the T on the outlet ball valve.

(I realize I will need to retune my setup once the HERMS coil is installed, but for now I would like to be able to set my strike and sparge water temp and not have to worry about overshooting.)

I should mention that the PV is correct and I've verified that the PID is Fahrenheit.

Any suggestions would be greatly appreciated.

Sincerely,
Ryan...

Sounds to me that you may have a shorted ssr. With the pid off check to see if you have voltage on both sides of the output of the ssr with respect to neutral. You should only have yoltage on one side. If on both replace ssr.

Thanks for the quick reply. That sounds reasonable. I will check it out.

What specific temperature probe are you using? If the SYL-2352 PID is not set for the correct probe the result is what you are experiencing. I've seen that happen with a RTD probe and the PID set for a Type K probe. You might want to call Auber Instruments for additional help.

Wishing you the best.

P-J

If it is not the setting for the thermocouple, then it is likely the ssr. Did you get one from Auber or the cheapo from China off of Ebay? If the latter, get one from Auber, much better quality.

Thanks P-J for pointing out an alternate possibility. The probe is a Pt100 RTD from Auber. The 2352 is Sn code is set on 21, so we are good there.

I'm going with a bad SSR. The SSR is the only thing I went cheap on. I took a gamble on it, but it looks like it isn't paying off.

I'm going to stick with Auber from here on out.

Thanks to all that replied.

Ryan...

Sanity check:

Is the relay latching?

Since you are measuring an rtd, verify that there is current present. I'm not familiar with the auber controller, do I don't know what the current should be. 488 micro amps is what I have seen in other devices.

Did you get a 2, 3, or 4 wire rtd? The manual shows the device has provisions for 3 wire only. 2 wire rtds are simple. One wire goes to terminal 5 and the other goes to both 3 and 4. A 3 wire rtd should have 2 wires that are the same color and one that is different. The two wires that are the same color should have no resistance between them. The resistance between the third wire and either of these 2 wires should be the same. A 4 wire rtd may have 2 sets of wires the same color, or 4 different colors. The check is the same...two wires should have no resistance between them, and the resistance between the other two should be the same.

Get out your trusty ohm meter and do a 2 point check. Stick the probe in an ice bath. After 5 minutes or so, you should read a resistance of 100 ohms. Stick it in a boiling water bath. After 5 minutes, you should read 138.5 ohms.

You can also try manually triggering the relay with a separate power source, to insure that it doesn't "stick". It is also possible that you ran AC power through the DC coil (for lack of a better term) on the relay and fried it.

I have a similar question. I hooked everything up last night and added a 120v LED on the side of the coil that goes out to the element. When I turn on the element, the out light goes on and off which means the pid is sending a signal. I also see the light on the ssr in synch with the light. However, the led stays lit the whole time. I took a volt reading across the hot /neutral on the side of the coil going to element. When pid is firing I get 120v, when off I get 55-60, volts. This is a 120v system. I have read of leakage, but this seems high. Is this normal operation? I also hear a buzz from the coil, but figured this is normal sound. Yes there is a louder mechanical click sound when element button is first engaged and I know that is the magnetic coil closing. Thanks for any feed back.

Jps101 said:

--- added a 120v LED on the side of the coil that goes out to the element. --- However, the led stays lit the whole time. --- When pid is firing I get 120v, when off I get 55-60, volts. ---

Click to expand...

This is normal behavior because you do not have a load wired to your SSR output. Connect the load (element) & test it again. With that, I'm sure it will behave as you had expected.

P-J said:

This is normal behavior because you do not have a load wired to your SSR output. Connect the load (element) & test it again. With that, I'm sure it will behave as you had expected.

Click to expand...

Paul,

Thank you as always. Couple more questions, I was reading the 2352 manual and it states I can use 18-26 awg wire from power source, does this also suggest I can use 18-26 wag wire out to the SSR? Also, can I run 14 awg in other spots expect where power is going to from the coil and output side of ssr? I am using a combo of your drawings. A4-2000w-biab-120v-d and another that has a main power switch for the system. It was used for a RIMS set-up, but I chopped off the bottom when I printed it.

EDIT

I have a bunch of 22 awg, that would be perfect.

The control signal to the SR is 12V and in the mA range, so small 22GA wire is adequate.
For the power to PID, make sure the wire is rated for high voltage, don't use CAT5.

I found alarm and sprinkler wire at the local HD that was rated for 250volts for my low current wiring.

Jps101 said:

Paul,

Thank you as always. Couple more questions, I was reading the 2352 manual and it states I can use 18-26 awg wire from power source, does this also suggest I can use 18-26 wag wire out to the SSR? Also, can I run 14 awg in other spots expect where power is going to from the coil and output side of ssr? I am using a combo of your drawings. A4-2000w-biab-120v-d and another that has a main power switch for the system. It was used for a RIMS set-up, but I chopped off the bottom when I printed it.

EDIT

I have a bunch of 22 awg, that would be perfect.

Click to expand...

The power input to the PID and from the PID to the SSR control can be minimal wire size as you queried. The circuits that need the heavy gage wire are the power circuits to the elements.