Vibiemme Domobar Super

Love / Delta 32B PID Parameters

.0625 T thermocouple immersed in boiler

When I originally set up the PID, optimized it for maximum boiler stability. After a few months it became clear that maximum boiler stability is not optimum for an HX when making several shots in quick succession.

Updated Brew Mode

Set 234°F

P = 0.5°F

I = 180 seconds

D = 4 seconds

IoF = 0% *

Pd = 0.5sec

Original Brew Mode

Set 234°F

P = 7.6°F

I = 90 seconds

D = 15 seconds

IoF = 8.5% *

Pd = 0.5sec

HX Steaming Mode [Now Used as pStat controls Steam mode]

Set 250°F

P = 2.0°F

I = 0 seconds

D = 0 seconds

These parameters were determined by manual tuning according to this document

http://www.omega.com/temperature/Z/pdf/z115-117.pdf

* this parameter is normally set by auto tune. When the system is stable, this is a default percentage output to maintain the set point. In practise, this parameter is only useful when the machine is idle for a long period. When pulling shots, the system is not stable, so the PID parameters are used to adjust the output percentage.