I'm in the process of building my new HERMS controller. My HERMS system will be very basic, I'm building it to be very portable. I'll be using a 1500W heatstick in my HLT, the controller will control this and I'm using a toolbox as the housing for the controller. I have a similar toolbox build housing my March pump. I'm thinking about incorporating my March pump into the HERMS controller box so I only have to deal with one box instead of two. Any reason not to have the March pump in the same box? I'll be using a PID/SSR. I realize the SSR can put off some heat, and so will the pump, so I'll put in a vent and/or PC case fan to help remove heat if necessary.
quick HERMS controller build question
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jeffmeh
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The primary reason would be to avoid the potential for liquid in the control panel. If you do it, either mount the pump so the wet end is outside the box, or take great care with your liquid connections, preferably both. The other reason is heat, as you mentioned, as without the pump you would be able to use an external mount heat sink with passive cooling, avoid the fan, and keep the box liquid tight.
Yeah the pump will definitely be mounted so that the head is OUTside of the box, while the main body of the pump will be inside the box.
BadNewsBrewery
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Then your only real concer is heat disipation. Put a passive vent on one side, and a fan blowing warm air out on the other side, and you should be good. If you're concerned about getting the box wet and sucking water into the box, you could put baffels or some sort of a vent cover on the intake to reduce the chances of liquid being sucked in.
One more question... I'm putting an on/off switch in for the heating element, where is the best place to put it... Should I have it so that it switches the PID on/off, or should I put it in the hot line coming out of the SSR? Or does it really matter?
BadNewsBrewery
Well-Known Member
SSR's will allow some amount of current through, even when they're "off". They also have been known to fail in the closed position, meaning you'd think it's off, but it's firing the element. For these reasons, it's a good idea to put some sort of switch / contactor in the power supply line going between your source, the SSR, and the element - whether you switch the load side of the SSR or the line side doesn't matter.
As for having a switch that also turns on / off your PID - this is a portable box, right? So when the PID is off, you're probably not using the box, so just unplug it.
As for having a switch that also turns on / off your PID - this is a portable box, right? So when the PID is off, you're probably not using the box, so just unplug it.
One other thing to consider is where you'll mount the control panel. For a few minutes during my build, I was going to mount the control panel under my stand. I decided that putting that box underneath a couple hundred pounds of water was a horrible idea, and mounted it on the garage wall.
If you put the pump in your CP, I think you'll end up needing the CP to be lower than your kettles, in order to most easily prime the pump.
Think about your brew process, and the amount/length of silicone hoses you'll be needing to move your liquids around.
Good luck!
If you put the pump in your CP, I think you'll end up needing the CP to be lower than your kettles, in order to most easily prime the pump.
Think about your brew process, and the amount/length of silicone hoses you'll be needing to move your liquids around.
Good luck!
MadGus said:
I agree about thinking about the process. I you put the pump int he box, it will be a pain bending over to get to switches and the pid. You probably won't have to use them often during the brew, but it would be easier both to switch and read if they were higher
