SSR wiring

[Cheeseguy]

Greetings!

I'm new to the board and probably in way over my head. I have a small farm in north Idaho. We raise sheep, mostly for meat, but in an effort to maximize revenue income, we milk them also. We make lotion, soap, and cheese from the milk.

I bought a cheese vat from Germany, and the heating element started leaking water. I was never impressed with the element to start with. It has a manual temperature setting knob marked off in 5 degree C graduations. Most of my cheeses require 86-102 degree F temps. The slightest movement of the knob was 3-4 degrees, enough to make a huge difference.

The water jacket of the vat holds roughly 5 gallons of water. I replaced the 3000 watt original heating element with a 4500 watt unit from Home Depot. I just purchased a JLD612 controller, a 60 amp SSR, heat sink, and pt100 probe.

I'm completely lost when it comes to PID settings, but I'm sure it will auto tune to be just fine. I was looking at the manual for wiring all of this together, and I have a silly question. The element requires 240 VAC to function. The SSR only has the ability to control 1 "leg" of my 240 V power. DO I wire the other leg to the element and let the SSR complete the circuit? That is what it looks like in the diagram, but I wanted to make sure.

Thanks in advance.
Dale Pratt.

[richiem]

That should work fine.

If you have some or can get some, use a little thermal paste like Arctic Silver between the SSR base and the heat sink. This stuff is used by computer geeks who install CPU chips to motherboards, so is generally easy to find. Just a very thin coat to fill any gaps between the two surfaces.

[Cheeseguy]

Thanks! I think I have some left over from the last 4 or 5 computers I built.

Speaking of heat dissipation, I was going to put this in a 8x6x3 project box from Radio Shack. I figured I was going to need to drill some vent holes, do you think I'd need to put a fan in it too? The wires get warm (103 F)but not hot, and only right next to the element. The initial warm up of the milk takes about 30 minutes, but the vat is very well insulated and will hold the 86-103 temp for hours once it reaches temp. Unplugged, it will only lose maybe 5 degrees overnight.

Thanks again,
Dale.

[richiem]

I have a couple of times cut a slot in a box the dimensions of the center web of the heat sink closest to the mounting base for the SSR, and slipped the heat sink into the slot, with the SSD inside the box and the heat sink outside. That way there was ambient around the heat sink but the wiring was protected. Pix attached --