Asco PID wiring question

I am using two solenoid valves to divert wort between a HERMS coil and recirculation line. Would I use two normally closed valves? How would this be wired to the controller. If valve #1 recirculates to the MLT while the switch is closed for and valve #2 goes to the HERMS coil when the switch is activated, then:

1. Would the recirculating valve be wired to the NC terminal and the HERMS valve be wired to the NO terminal? I guess I'm trying to figure out if the normally closed valve will be open (activated) for recirculating when the Love control common is switched to the NC terminal and closed when controller switches on for HERMS ramp.

I hope that makes sense.

KD

Assuming your temp controller is set to Close on fall, the recirc line asco needs to be NO and the HERMS loop one needs to be NC. See, when the temp is above your setpoint, it will recirculate (no power to either valve). When it falls below setpoint, power flows to both valves. The recirc closes, the HERMS opens.

If I'm not mistaken, an easier way to do it is to always run the recirc through the HERMS coil and just use a single temp controller. The probe would go in the recirc path on the output of the HERMS and it would be controlling the gas to the HLT. This assumes you're already going to regulat the HLT temp to some degree above the mash temp anyway right?

Bobby_M said:

Assuming your temp controller is set to Close on fall, the recirc line asco needs to be NO and the HERMS loop one needs to be NC. See, when the temp is above your setpoint, it will recirculate (no power to either valve). When it falls below setpoint, power flows to both valves. The recirc closes, the HERMS opens.

If I'm not mistaken, an easier way to do it is to always run the recirc through the HERMS coil and just use a single temp controller. The probe would go in the recirc path on the output of the HERMS and it would be controlling the gas to the HLT. This assumes you're already going to regulat the HLT temp to some degree above the mash temp anyway right?

Click to expand...

Yeah, that's what I thought too originally. Maybe i thought about it too long. Thanks for the clarification on the NO/NC issue. As far as the recirc going through the HERMS, I would think you would not get as good control as diverting the recirc to a dedicated line. I have two controllers, so I will use one for HLT and one switched between gas valve and herms operation. I'll run a tee off the MLT out into the two valves with the probe in the mash.