To minimize how often the pumps turns off and on, it seems like you could throttle the flow of the pump to be just barely more than the flow rate of your MLT. This way the pump would have to run for a few minutes to catch up to and get ahead of the mash tun.

Are those of you with the float in the mash tun and are using it to turn off the HLT pump just opening the HLT valve all the way?

Linc

I understand what your saying about throttling it, but it doesn't quite work like that. That float only has about a 1/8" difference in level between on and off, so, yes, if you put less in at a time it will slow the change in on/off a bit, but not enough to keep the pump from going on and off a LOT, and by slowing it you will have to sparge for a LONG time. the best thing is to wire in some sort of delay on the pump going back on, although i don't know how to do that yet, still reading.

are the march pumps an impeller pump, whereas it wouldn't be a big deal if the output was closed and the pump is still running? I guess this is the case, since using a ball valve is the general way of controlling the flow. Wouldn't it be much easier to use a mechical style float valve, similar to how a toilet works?

Hey scooter... check out these controllers. I think you will find one that you need. They have logic to either pump up or pump down. Push used a version for his grant. I'm using another type for my HLT that will allow me to flip one switch to fill the tank. The contact on top will stop it from overfilling, and the contact on the bottom will keep the burner from coming on once the water falls below the bottom contact (and stops it from coming on until it passes the lower).

The one I am using for this particular application is : LNC-NS210-024

http://www.nationalcontrols.com/product ... 1&mode=sku


Mylo

Hey, thats perfect. That's exactly the logic I need, not the one with the heater though, just a pump on/off with a high and low, AND it operates off of 120v so no need to wire in separate transformers and all that fun stuff. Where did you get yours?

Check out www.weisd.com - I haven't bought mine, yet - but that is where I was going to go.


Mylo

Ok, great. It looks like the wiring, which makes sense, needs to stay out of the liquid, and the probes are basically just a long piece of s.s. Are you planning on using their probes/holders or do you think it would make more sense to design something better suited for this application. That is, if you use their static probes, they will always be at a set level, whereas grain beds tend to fluctuate in height from beer to beer. Do you think you could basically use any conductive metal as long as the other wire was grounded? I understand the logic of the board, when it makes contact with liquid it completes a circuit to the ground probe, but not sure what the best application is. I like the idea of having the probes attached to the sparge arm, like with the float switches, however not sure of the safest way to do this. If you have any ideas it would be helpful, i definitely want to go with this system, for $40 plus the probes, maybe a total of $100 it is the best way to ensure my pump doesn't wear itself out early, and no need to buy relays, cap/resists and set up my own circuitry. Any ideas?

Thanks again.

I haven't worked out those details yet, for mine. I imagine you just need a conductive piece of metal that is electrically isolated from the kettle. You might need a little MacGyver-like inspiration. My brain is fried. Mine will be in a fixed location - so I might go with a high-temp polysulphone bulkhead fitting with a piece of stainless going through the middle. Or, I'll just bite the bullet and buy their probes.


Mylo