PID programming of 4 group La Marzocco FB70

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rattaps
Posts: 110
Joined: 14 years ago

#1: Post by rattaps »

Hi,
Just finished installing a PID on the left side boiler, programmed the PID part manually like i found on the espresso sites, P = 0.5 I =225 D =4 and found a couple other settings that i did, and also programmed in the
TC = 2 (cycle time)
Pn2 = 2 (Type of thermocouple 2=J)
P-SL = 32 (lower measurement limit)
P-SU = 220 (Upper measurement limit) (determines full scale reading)
Sv-L = 180 (Minimum set value)
Sv-H = 220 (Maximum set value)
Pdp = 1 (do this last for 1 place decimal place)

but still, it seems like it's either not getting the boiler full power or i'm expecting too much, i let the boiler heat up overnight, in the morning i let one group run for approx 45 seconds to fill two 9oz cups and the boiler was set back to 192f, i have the controller set on 203F now, does that sound normal? it takes approx 3 min to recover back to the 203,
"The only stupid question is one not asked."

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Compass Coffee
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Joined: 19 years ago

#2: Post by Compass Coffee »

Yes it sounds normal, drawing off ~18oz water from a 3.4L (~115oz) boiler that's NOT fed with HX pre-heated water. Remember a PID will bring the temp back up slower that a tstat pulsing power to the heater rather than flat on. To avoid (massive) over shoot of course. Even just pulling back to back shots, much less water draw than you did, with short post shot flush I have to alternate pulling from left/right boilers on our 4 group PID'd Linea to have any kind of pace.
Mike McGinness

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rattaps (original poster)
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Joined: 14 years ago

#3: Post by rattaps (original poster) »

Thanks, i just wanted to know if my programming was correct, i thought its giving the element 100% power until its close, then it starts to pulse until the desired temp is reached
"The only stupid question is one not asked."

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Compass Coffee
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#4: Post by Compass Coffee replying to rattaps »

To be clear I wasn't saying your PID programming was right OR wrong! I've been running my 4gr Linea at the Roastery with twin PXR3's, simply ran autotune and let 'em setup themselves, did it a couple times, and for the life of me have not taken the time to figure out why the left boiler recovers a bit slower (noticeably) than the right. Only been that way for 5 1/2 years. :oops: :lol: I don't rightly recall how far below set-point mine has drop before PID gives full power. I'll pay attention to the red heater light on the PXR3 and see sometime, if/when I remember.
Mike McGinness

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rattaps (original poster)
Posts: 110
Joined: 14 years ago

#5: Post by rattaps (original poster) »

ok, i see,
it's not a good way of setting it up, at least go in and set the PID part of it, also turn on the FUZY and set the high and low limits, incase there are overheating problems,
"The only stupid question is one not asked."