temperature controller issues

[big_al]

G'day,

wondering if anyone can help me sort out a temperature controller on my fermenter. Have had a couple of batches now where the solenoid opens to keep the temperature down, but stays open and the result is wort way down below ferment temp. They are "fusi" controllers that I got secondhand with my brewery. Only one out of 6 s having problems, others seem ok.

For example:
my last batch started fermenting like crazy and got up to 83F before I turned on the ball valve to let the glycol pump through. Set the SV at 74F (Belgian yeast) and let it go overnight. Came in the next morning and the PV is at 53F and the yeast had stopped.

all settings seem identical to the other controllers...

any thoughts?

Allan
Tanglehead Brewing Company
Albany, Australia

[lhall]

It sounds like a solenoid valve sticking to me. That's the actual valve that opens and closes to let the glycol into the tank, not the controller that is actuating it.

Most of these solenoid valves have small ports that use differential pressure to open and close the valve, and they can become clogged. Try taking the valve apart and making sure all the ports are clean and clear.

We use Asco Red Hat valves that I get from Grainger here in the states. We use a zero-pressure differential valve. When we used a five psi differential valve we had lots of problems with valves sticking open or closed.

[big_al]

yeah, someone else has suggested the same thing.
Will need to take it apart and see how it goes and/or replace it.

thanks

[RaySherwood]

"Y" strainer

You may want to install a "y" strainer right before the solenoid, that'll help save future batches.

[Hofer]

...sorting out

G'day,

wondering if anyone can help me sort out a temperature controller...

Just in case, check that direct operation mode (cooling) for controller is selected. To sort out the suspected controller, you can set SV 0.1C (F?) less than existing PV.
When PV gets that set value the output indicator turns off (no more cooling).
If the PV continues to drop it means solenoid, relay or other problem.

Leonid

[fcaseyf]

Your solenoid could be a normally open valve instead of normally closed. Energize the solenoid and then touch a screw driver to the coil and see if its magnetized, if it is its the solenoid, if not its the coil.

[liammckenna]

Little bits of teflon/ptfe/plumbers tape.

Cleaned more bits of this out of solenoids than I care to recall.

Never thought of a strainer...what a great idea.

Pax.

Liam