Profitec Pro 700 too hot at group - Page 2

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blazko

#11: Post by blazko »

Hello folks,
just found this thread and out of curiosity checked my PID settings. Found out the "d" value was set to 8. I actually reversed it back to factory recommended settings but to be honest I have no idea what I actually changed.
Could anyone point me a nice PID explanation? Im sure somebody already wrote it.

Thank you

EDIT: found it (sort of) Good all round explanation of PID stuff

blazko

#12: Post by blazko »

One other thing that i cant sort out is this:

E1 value is set to 14; t1 is set to 92 Celsius and in group Erics thermometer shows 96 C during extraction.

T1 set to 88C = 92C on Erics thermometer.

Any idea, how to play with these values to match more closely both temps?

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erics
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#13: Post by erics »

You don't necessarily want to match those temps because the two sensors are measuring different temperatures. See the PDF document I sent you.

A reasonable group temp when the machine is fully warmed up and just sitting there at idle is 196-197 F (91.1 - 91.7 C).
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

blazko

#14: Post by blazko »

Hi Eric,
thanks for the reply - i read the pdf but still i'm confused.
Here is what i observed:

1) Boiler temp (t1) set to 90C gives a 85C (on group - your thermometer) read on idle machine - after 60min of sitting there idle... (room temperature is around 26-28C at the moment)
2) When water is flowing thru an empty basket on group reading jumps to 93C and keeps it for 25sec that I tested
3) When water is flowing on a blind basked (or coffee), after a couple of minutes of recovery just in case, on group reading gives me 91C - this value +/-0,5C is also constant during 25"-30".

So basically to get to this point:
A reasonable group temp when the machine is fully warmed up and just sitting there at idle is 196-197 F (91.1 - 91.7 C).
I would have set t1 boiler temp to ~95C - but this would result in some crazy temps while brewing.

I still hope that there is an optimal p-i-d value set that in conjunction with properly set E1 would give similar reads at both measuring points and from what I observed (unless i didn't get anything wrong) this is what I should be aiming for.

kwantfm

#15: Post by kwantfm »

Just purchased a Profitec 700 today (replacing my much loved Technika Profi IV). Played around with the Scace and found brew temps to not match PID readings... as per this thread found d to be 8 and changed back to recommended 4. Now Scace is showing on the money brew temps. Thanks so much for sharing in this post, I would have gone crazy without this information!
LMWDP #602

blazko

#16: Post by blazko »

kwantfm wrote:found d to be 8 and changed back to recommended 4. Now Scace is showing on the money brew temps.
How about E1? Today I played with it and found that E1=10 gives me *almost* exact temps from PID (t1) and Eric's thermometer.
The rest is as per manual:
P=2,5
I=0,02
D=4

kwantfm

#17: Post by kwantfm »

Had a bit more of a play this evening. E1 at 12 produces good numbers for me. In addition I was a bit concerned about PID overshoot when the brew boiler is heating post extraction. My target brew temp is 92*C and I was finding that the PID reading could get to 95*C. Please let me know if my thinking is not accurate but I am happier with a more gradual approach to target from the low side rather than quick heating beyond target and then relatively slow loss of temperature to return to target. I also have relatively slow work flow as I hand grind with an HG one. I altered the P constant to 0.9 (manufacturer's recommendation at 2.5) and have found that PID reaches 92*C in about 40 seconds post 27 second extraction.

I've found that intrashot temperatures tend to rise with an average rise of about 0.5*C up to the very occasional 1.0*C rise (I haven't been able to determine what factors affect the size of this rise).
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jonr

#18: Post by jonr »

kwantfm wrote:(I haven't been able to determine what factors affect the size of this rise).
Perhaps the group temperature at the start of brew.

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erics
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#19: Post by erics »

. . . and I was finding that the PID reading could get to 95*C. Please let me know if my thinking is not accurate. . .
What the PID reads is only sorta relevant. When you have about 30 grams of liquid going up against ~ 4200 grams of brass, who ya think is going to win? :)
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

pizzaman383
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#20: Post by pizzaman383 »

Does the Profitec Pro 700 use the steam boiler to preheat water entering the brew boiler?
Curtis
LMWDP #551
“Taste every shot before adding milk!”