New PID, Broken PID or Coil? Negative Numbers.

[GrassFed]

Just got a new PID controller and coil.

This is what happen;
On start up, it counts backwards in to negative numbers till it gets to about -300 then it flashes EEEE. The coil is heating up as the numbers go negative, then as the temp drops and it goes from EEEE to -280 then heats the coil back to -300 & then EEEE

Anyone had this before. is there a fix? any help is welcome.

Could send it back, but most likely cost more to ship it back than buy a new one..

Here's a vid of what its doing

https://imgur.com/a/DrsXPNS

 

[Bologna]

Just got a new PID controller and coil.

This is what happen;
On start up, it counts backwards in to negative numbers till it gets to about -300 then it flashes EEEE. The coil is heating up as the numbers go negative, then as the temp drops and it goes from EEEE to -280 then heats the coil back to -300 & then EEEE

Anyone had this before. is there a fix? any help is welcome.

Could send it back, but most likely cost more to ship it back than buy a new one..

Here's a vid of what its doing

https://imgur.com/a/DrsXPNS

I know nothing really about all this stuff, but are the pins correct? Were they purchased as a set? Does the controller have other modes?

 

[GrassFed]

Thank you for the response.

I purchased as a set. Not sure what you mean by other modes. I have not taken it apart.

 

[GrassFed]

Just had a look through the system, this is what it is set to.

PID

Inty = K
Outy = 2
Hy = 0
Psb = 0
Rd= 0
CorF = 1

P= 5.0
I= 100
D= 20
SouF= 0.2
Ot= 2
Filt= 0

SV= 580
AH1= 300
AL1= 300

 

[Rodney]

I do not know much about this either but I checked and this guy is getting same thing happen.

https://www.reddit.com/r/ranciliosilvia/comments/x846le
I really hope you get it fixed mate.

 

[Bologna]

Thank you for the response.

I purchased as a set. Not sure what you mean by other modes. I have not taken it apart.

You're very welcome, and welcome to the forum...!

So, like a "matched" set and should be plug n play basically, ready to go, I assume...?

Just wondered more if the PID was a separate purchase, maybe it was set for a dif coil, or whatever, again, I really have no idea... but I'm sure someone with a shitton more knowledge than I will eventually respond... good luck...!

Edit: Like maybe @Hippie....?

 

[Hippie]

I saw the thread and hoped someone else would know to be honest
It's probably either the thermocouple, the chip or the settings on the chip
Another coil and controller would be handy to mix and match to hone in on the issue
My best guess is the coil (thermocouple) as the chip is powering up and doing something - and I have had a bad coil that would heat up a little before the controller started showing EEEE
With the numbers dropping, I wonder if the thermocouple is wired backwards?

 

[Grass Yes]

Just had a look through the system, this is what it is set to.

PID

Inty = K
Outy = 2
Hy = 0
Psb = 0
Rd= 0
CorF = 1

P= 5.0
I= 100
D= 20
SouF= 0.2
Ot= 2
Filt= 0

SV= 580
AH1= 300
AL1= 300

Your values seem to mostly match the factory defaults, so I do believe there is something wrong with the PID or coil.

https://cdn.shopify.com/s/files/1/0337/9354/0236/files/XMT7100_PID_manual.pdf?v=1584376326

I'm assuming this is a typical k-type coil, etc.

I'd try an auto tune, if I were in your situation. If that doesn't help, I would try a new coil first. Or if you have a friend with the same pin out, you could try your coil on their PID controller.

With the numbers dropping, I wonder if the thermocouple is wired backwards?

This should be easy to determine with a multimeter. Good call.

How To Find Your Heat Coil's XLR Plug Pin Wiring Compatability

It's of the utmost importance to make sure that the XLR pin wiring order on your heat coil's plug matches your controller.

rcctools.com

 

[GrassFed]

Thank you for all the responses.

I'm confused that the coil is heating up, as the temperature reading is going down into a negative.

At this point, it's a paper weight. I'm hoping the seller is going to ship me a replacement.

 

[highvaper]

Sounds like the thermocouple is wired the wrong way round

I suspect its a thermocouple based on the max6675 or similar

See: https://protosupplies.com/product/max6675-thermocouple-temperature-module-2/

Module Connections​

When hooking up a thermocouple, the red lead of the thermocouple typically attaches to the ‘+’ terminal on the module. If the reading goes down when temperature increases, then the leads should be reversed.

 

[Radwin Bodnic]

I'm confused that the coil is heating up

Negative temperature are under the set (goal) temperature of the PID. This is why the coil heat up : the PID try to reach the set temperature.

This is highly schematic but this is the expected behavior :

(Not picturing start up, overshoot and corrections.)

What is happening to you is that the temp reading keeps going down, the PID is delivering full power continuously to compensate. At one point there is a limiter (maybe a timer) that prevent overheating : it shows an error code and cut the power.

As @Hippie and @highvaper mentioned, temp reading going down while the coil does heat shows that the thermocouple is wired the wrong way but the PID appears to have a normal behavior to me.

Just invert the thermocouple pins at the XLR plug of the coil (easy soldering with inexpensive tool) and my bet is that it will solve your issue. The temp reading will go up while the coil heat and the PID will be able to lower the power delivery down to its cruising level. It will prevent triggering the limiter and you won't have any error code.