How to build a control panel (part 1)

[grupe]

I got mine at auto zone or napa. I can't remember for sure.

 

[kal]

Any electronics shop. I think I got mine from the (now defunct) Radio Shack.

Kal

 

[Homercidal]

Radio Shack defunct?? I went there the other day and they are still online. (Though a shadow of their former selves, I admit.)

Anyway, just wanted to come on here and give thanks for your information. I'm in process of designing the layout of my own control panel and your build thread is most appreciated! I'm going to use many of your examples in my own system.

My current plans are for:

50A main power
30A each HLT and BK (In case I want to do a double batch and run the HLT for the second batch concurrently with the boil from the first.)
Single Pump
PID for HLT
PWM for BK

I'm also considering attaching a small LCD monitor to the panel and stashing a small computer inside the brewstand with speakers for jams while I brew. That way I can control the tunes without having to walk across the garage like I do now. Just need to buy a cheap trackball so I don't have to mess with a mousing surface.

Some of the electrical parts are kind of expensive, but I really want some of them, like the twist lock plugs and whatnot. Already got a nice panel from work and stripped it out and ready for new parts to go in.

 

[JayMac]

Hey Kal,

I was reading your guide, and I got a little confused. My system is going to be much different than yours, so I'm trying to figure out what is actually necessary.

I understand that you use a contactor after the main power switch because this way you can use a 120V key switch to complete the 240V circuit (the same reason an electric car uses one- the auxiliary systems can energize the main battery pack). However, in my system I'm going to be running a 120V, 1500W ULWD element, so I will be running my pump, electronics, and element of a dedicated 120V 15A receptacle (that's roughly 92% capacity, but I am lacking 20A breaker's in my main control box so I don't have much choice).

Here are my questions:
1. is a contactor required after the key switch if everything will be running at 120V? If so, why?

2. I see that you use contactors in conjunction with your SSRs. Is that necessary in the case of a RIMS system with just one element? I believe your reasoning is that even if I have my element switch off, the SSR still poses the threat of shocking me (I think that's what I read?). The addition of the contactor would of course prevents this entirely (right? haha).

3. I keep hearing that we are using SSR's because they have the ability to switch almost instantaneously. But in your design, you have a SSR and a contactor in series. Wouldn't that not only limit the speed of the response to the speed that the contactor switches (rate limiting step), but also force the contactor to switch faster than it's intended (whenever the PID says so instead of a couple times during the brew session).

Thanks,
Jay

 

[kal]

1. is a contactor required after the key switch if everything will be running at 120V? If so, why?

If your main power switch can handle all the power you expect to put through the panel, no contactor or relay needed. Confirm the switch you want to use as many are only good to 10A.

2. I see that you use contactors in conjunction with your SSRs. Is that necessary in the case of a RIMS system with just one element? I believe your reasoning is that even if I have my element switch off, the SSR still poses the threat of shocking me (I think that's what I read?). The addition of the contactor would of course prevents this entirely (right? haha).

Correct. Read the "How it works" section on this page:
http://www.theelectricbrewery.com/control-panel-part-2?page=13

3. I keep hearing that we are using SSR's because they have the ability to switch almost instantaneously. But in your design, you have a SSR and a contactor in series. Wouldn't that not only limit the speed of the response to the speed that the contactor switches (rate limiting step), but also force the contactor to switch faster than it's intended (whenever the PID says so instead of a couple times during the brew session).

SSRs are used because they're meant to be switched on/off a lot, often many times a second. A relay is not meant for that. See the "How it works" section again in previous link I posted. It explains it.

Kal

 

[joety]

JayMac, I built the panel you describe, albeit for 20a. If you look at the pics, I have one in-line fuse for the lower amp stuff which allows me to use thinner guage wire, and one for the higher amp stuff (the fuse box). I did use a contactor for the main power as well as the SSR. I think you're a little confused and not sure if Kal's response will make sense to you. The contactor for the SSR is wired to be turned on/off from a switch on the panel so you can cut power to the heating element without shutting off the whole panel. When you start brewing you'll understand why this is helpful. It is not used to turn on/off the heating element to control the temp, that's what the SSR is for. When the contactor is off, the PID will attempt to fire the SSR (and thus the element) and no power will actually go through the element. When it's on its like it doesn't exist. The PID will fire the SSR and element rapidly as it tries to control the temp.

I hope this helps. I wish I had a good schematic of my setup but I can't even find my rough drawings and after looking at Kal's first rate diagrams they would not impress.

 

[kal]

Fast forward to today: The control panel is still working great - I brewed batch #157 last week in my new brewing room where it now sits.

I painted the back panel that is used to hang it on the wall a darker grey colour to better match the wall tile (no more darkbrown/rust colours):

Kal

 

[Tiber_Brew]

Looks great, bud! How's the beer flowing?

 

[kal]

The beer is flowing very nicely! Thanks for asking!

Kal

 

[Tiber_Brew]

By the way, I dig the apron. I didn't quite picture you in Carhartt overalls and swampers, but I figured you'd have some sort of brewing garb.

 

[kal]

By the way, I dig the apron. I didn't quite picture you in Carhartt overalls and swampers, but I figured you'd have some sort of brewing garb.

Thanks! I mostly just wear it near the end of the brew day (after the boil has started) and I've started to clean things. Mostly from stopping me from from getting wet from the sink/spray-arm.

Kal

 

[Im_Lars]

Thanks! I mostly just wear it near the end of the brew day (after the boil has started) and I've started to clean things. Mostly from stopping me from from getting wet from the sink/spray-arm.

Kal

I wear an apron also for the same reasons. I got an idea, someone needs to come up with a HBT and or The Electric Brewery apron.

Edit: I see you have them on your site already.