30A 240v 3 wire control panel

[superbob404]

Lots of 240v 4 wire set ups out there, if only I did more research before I built my house! I have a 3 wire, no neutral. I bought all my components & the book from theelectricbrewery.com, they have been great to work with.
Is there anyone out there willing to take a look at my wiring diagram? I think I finally have it, just want to make sure.
Thanks in advance!

 

[superbob404]

a little more info might help...
PID is Auber 2352
SSR is Auber SRDA40
Relays are Automation Direct AD-PR40-2A-240A
Input power from a L6-30R
All LED's & switches are rated for 240V

 

[doug293cz]

There are a number of problems with this design, the biggest being the lack of a switch controlling the coil current on the element power enable contactor. I don't have time to do a full review tonight, but will try to get to it Tuesday.

Brew on

 

[superbob404]

There are a number of problems with this design, the biggest being the lack of a switch controlling the coil current on the element power enable contactor. I don't have time to do a full review tonight, but will try to get to it Tuesday.

Brew on

Thanks for any help you have, no hurry.

 

[superbob404]

There are a number of problems with this design, the biggest being the lack of a switch controlling the coil current on the element power enable contactor. I don't have time to do a full review tonight, but will try to get to it Tuesday.

Brew on

After even more research, switch controlling the element makes a lot of sense. I updated my diagram, I assume just a switch on the bus 1 line would do the trick.

 

[doug293cz]

Your modified design looks like it's ok. However, I would recommend switching both hot legs feeding the main power contactor (it's likely the switch you got is already double pole), and connecting "Bus 2" to the output of the contactor, rather than directly to the power input. By doing it as I suggest, you will not have any voltage on either bus when the main power switch is off.

You could build this controller with only one contactor, but since you have two, you might as well use them.

Here's how I would do it. This design uses a different "PID" so terminal assignments are different. It also include a volt/amp meter and and external alarm buzzer, both of which could be left out.

Brew on

 

[brumateur1]

Usage of two relays/contactors is not only unnecessary but also increase a chance of failure.
Doug's schematic is what you need. You can simplify it by removing buzzer circuit and volt-amp meter. And you can use a single pole switches for PID and Element power control.

 

[doug293cz]

Usage of two relays/contactors is not only unnecessary but also increase a chance of failure.
Doug's schematic is what you need. You can simplify it by removing buzzer circuit and volt-amp meter. And you can use a single pole switches for PID and Element power control.

I recommend keeping a double pole switch, at least for the main power, so that when this switch is off, the only places where any voltage exists in on the inputs to the main power switch and the contactor. Nothing else in the enclosure will be hot with the main power switch off.

Brew on

 

[passedpawn]

Your modified design looks like it's ok. However, I would recommend switching both hot legs feeding the main power contactor (it's likely the switch you got is already double pole), and connecting "Bus 2" to the output of the contactor, rather than directly to the power input. By doing it as I suggest, you will not have any voltage on either bus when the main power switch is off.

You could build this controller with only one contactor, but since you have two, you might as well use them.

Here's how I would do it. This design uses a different "PID" so terminal assignments are different. It also include a volt/amp meter and and external alarm buzzer, both of which could be left out.

View attachment 600455

Brew on

Just curious, why not use a 240V 30A DPST switch on the main power in, in place of the the keyswitch/contactor? Nothing wrong with the dwg above, just wondering why people go this route. That switch is available at HD.

 

[brumateur1]

Just curious, why not use a 240V 30A DPST switch on the main power in, in place of the the keyswitch/contactor? Nothing wrong with the dwg above, just wondering why people go this route. That switch is available at HD.

Wiring convenience. By using a relay/contactor you can have only low amp elements on a front panel so you can use thin wires. Thin wires are more flexible, so you can easily open / close your controller box. When using a high amp switch it's better to put it on a side wall of your box.

Upd: And that switch doesn't look cool

 

[doug293cz]

Just curious, why not use a 240V 30A DPST switch on the main power in, in place of the the keyswitch/contactor? Nothing wrong with the dwg above, just wondering why people go this route. That switch is available at HD.

Yeah. the Leviton 3032 (and equivalent) switches work fine, and I have a design that uses that as well (see below.) In this case the OP already has the components (IIRC), so might as well use them. There are a couple of reasons not to use a 3032:

1. The aesthetics are lacking. Some folks just don't want something that looks like a light switch on their cool panel. No right or wrong answer here.
2. You cannot implement a "safe start" interlock unless you use contactors. With more complex control panels it's nice to prevent pumps and elements from powering on unintentionally when the main power is turned on.

Here's the really simple 240V only controller design:

Brew on

 

[superbob404]

Your modified design looks like it's ok. However, I would recommend switching both hot legs feeding the main power contactor (it's likely the switch you got is already double pole), and connecting "Bus 2" to the output of the contactor, rather than directly to the power input. By doing it as I suggest, you will not have any voltage on either bus when the main power switch is off.

You could build this controller with only one contactor, but since you have two, you might as well use them.

Here's how I would do it. This design uses a different "PID" so terminal assignments are different. It also include a volt/amp meter and and external alarm buzzer, both of which could be left out.

View attachment 600455

Brew on

Unfortunately, the switches I have are single pole, but I'll order a double pole, no voltage to either bus makes sense. I also can just unplug the control panel from the wall, but I dig safety! I wired the panel like my last diagram & it all worked great once I changed a few things on the PID. I left the cover of the panel off to make sure I didn't let out any of the smoke that comes prepackaged with these components(electrician joke!). Thanks for all the help! It seems strange how many different way these things can be wired & still work. I modeled mine off Kal's at theelectricbrewery.com.

 

[superbob404]

Usage of two relays/contactors is not only unnecessary but also increase a chance of failure.
Doug's schematic is what you need. You can simplify it by removing buzzer circuit and volt-amp meter. And you can use a single pole switches for PID and Element power control.

Two relays seems like a good idea according to Kal from theelectricbrewery.com. I modeled my diagram after his,eventually I will get into all grain, then there will be 3 relays. He knows more about this stuff than I do. One relay might have worked but I'm not sure how to wire it that way. I'll only be brewing twice a month maybe, so how fast will these relays wear out, I bet my SSR wears out first. I wired my panel like in my second diagram & it worked great. Weird how many ways there is to wire this stuff.

 

[brumateur1]

Two relays seems like a good idea according to Kal from theelectricbrewery.com. I modeled my diagram after his,eventually I will get into all grain, then there will be 3 relays. He knows more about this stuff than I do.

It's all depend. Some designs are require multipe relays. Butin that particular case second relay absolutely redundant. And every additional high current conections is potential cause of fire or failure. So it's better to minimize their amount if it doesn't defeat design goals.

 

[superbob404]

All I did was delete the HLT from the original design, how does that change the need for relays?
How would I wire it with just one relay?

 

[doug293cz]

As you have noted, there are many ways to design workable brewery controllers, and many choices for specific components. Personally, I have done many designs, and IMHO they have improved over time, as I found ways to simplify them, and add specific special functions. I learned a lot from the feedback of many HBT members, both on my designs and designs by others. I think the realization that a main power contactor wasn't needed (in most cases) came after Kal did his design(s). Early on, I usually included more contactors than actually needed.

Brew on

 

[superbob404]

Right on Doug, we all need to help each other...at 240V this is some pretty dangerous stuff. This has been one of the most rewarding projects I've ever taken on...& educational! I paint cars for a living!

 

[brumateur1]

All I did was delete the HLT from the original design, how does that change the need for relays?
How would I wire it with just one relay?

Just use that design - https://www.homebrewtalk.com/forum/threads/30a-240v-3-wire-control-panel.658944/#post-8457090

 

[superbob404]

nope, mine worked. If my house burns down you can say I told you so.