Simple questions about PJ design

[TheMerkle]

I found this PJ design and I'd like to build it. I just have a few questions I want to ask to make sure I get it right.

First, I know you need to 10 gauge wire to handle 30 amps, but I also know there are lines in the diagram that do not need to be so heavy. But, I don't know which I can sub or if I should use 10g throughout.

My other question involves the switches pictured. They appear to be 6 pins, but the switches I got were only three. Can someone help me find the switches PJ used in the diagram, or inform me on how to substitute the 6 pin switches with 3 pin switches?

Please, spare me the lecture about "if you have to ask these questions, then you shouldn't attempt this project"... I WILL figure out how to finish this and how to do it safely. I'd appreciate any help you guys can give.

 

[stratslinger]

When I built mine, I went 10G throughout - though I recently read somewhere that you can go smaller on runs that are less than a foot or two, I'm no electrician so I wouldn't go based on that memory.

As to the switches question: he actually doesn't have any switches, per se, in the diagram. They're all dual-pole electromechanical relays - you still need to wire in lower voltage switches to run the relays, but they basically work on the following principal:
there are two inputs, matched individually to a pair of outputs (ie, input a goes to output a, and b to b). Then there's a coil used for switching the relay on or off. Commonly this is a 120v circuit - neutral to one side, and a switched hot to the other. When you provide 120V (or whatever voltage your relay work at) to that coil, the circuit closes and voltage/current pass from the inputs to the outputs. When no voltage is applied to the coil, the relay is open and no voltage/current from the input reaches the outputs.

I'm not sure what you're looking at as 3-pin switches, but I suspect you're not going to get them to operate in this application.

For another perspective on how these things work, check out theelectricbrewery.com - that site has a step-by-step manual on how to set up a control circuit, complete with pictures of all components and descriptions of what's going on. Understanding that site will make this diagram MUCH easier to follow.

 

[TheMerkle]

In the image, PJ lists three SPST switches labeled '3 PID Power' '2 pump' and just '1'.

I see what you mean about the contactor, but I think the other three are switches, no?

 

[Ozarks Mountain Brewery]

there are very few amps drawing on the 120v end of it so 14 gage wire is fine for any 120v switch or even to the contractor if its 120v powered, the only thing that needs to be 10 is the power in to one leg of the ssr and one leg of the contactor and power out to the elements

 

[doug293cz]

...

As to the switches question: he actually doesn't have any switches, per se, in the diagram. They're all dual-pole electromechanical relays - you still need to wire in lower voltage switches to run the relays, but they basically work on the following principal:
there are two inputs, matched individually to a pair of outputs (ie, input a goes to output a, and b to b). Then there's a coil used for switching the relay on or off. Commonly this is a 120v circuit - neutral to one side, and a switched hot to the other. When you provide 120V (or whatever voltage your relay work at) to that coil, the circuit closes and voltage/current pass from the inputs to the outputs. When no voltage is applied to the coil, the relay is open and no voltage/current from the input reaches the outputs.

There is only one relay (the contactor) and four switches. The EPO switch is a single pole single throw (SPST) switch. The other three switches are double pole single throw (DPST), lighted switches. Each pole has two pins, and the light also has two pins, for a total of six.

I'm not sure what you're looking at as 3-pin switches, but I suspect you're not going to get them to operate in this application.

...

The three pin switches you have are most likely single pole double throw (SPDT). One pin is the common pin, one is a normally closed (NC) contact, and the third is a normally open (NO) contact. The NC contact is connected to the common when the switch is in the off position, and the NO contact is connected to common when the switch is in the on position. You can certainly use these switches in the design you chose, although you will not have the benefit of lights to indicate that the switches are on. You will want to switch using the common and NO pins.


Brew on

 

[doug293cz]

I found this PJ design and I'd like to build it. I just have a few questions I want to ask to make sure I get it right.

First, I know you need to 10 gauge wire to handle 30 amps, but I also know there are lines in the diagram that do not need to be so heavy. But, I don't know which I can sub or if I should use 10g throughout.

My other question involves the switches pictured. They appear to be 6 pins, but the switches I got were only three. Can someone help me find the switches PJ used in the diagram, or inform me on how to substitute the 6 pin switches with 3 pin switches?

Please, spare me the lecture about "if you have to ask these questions, then you shouldn't attempt this project"... I WILL figure out how to finish this and how to do it safely. I'd appreciate any help you guys can give.

If you have not purchased the major components yet, I suggest you look at some alternatives. Rather than using a PID controller (the Auber SYL-2352) I would recommend you use an Auber DSPR110 controller. It performs the same function as the PID controller, but does not actually use a PID algorithm (has a more "modern" digital based algorithm.) But in addition, it also has a linear, knob based power control for boiling, which is more convenient than the manual mode available on some PID's. It's also possible to eliminate the contactor by using a 30A DPST switch like the Leviton 3032.

I'll post a diagram a little later.

Brew on

 

[TheMerkle]

I do already have components in hand. The PID I ended up with is an AGPtek TA4-SNR

 

[stratslinger]

There is only one relay (the contactor) and four switches. The EPO switch is a single pole single throw (SPST) switch. The other three switches are double pole single throw (DPST), lighted switches. Each pole has two pins, and the light also has two pins, for a total of six.

You're absolutely right - sorry, my fault for posting with inadequate sleep!

 

[TheMerkle]

Reviewing the switches that came with the items I ordered, I see that the switch is indeed three pin. It is a simple toggle switch with an off position and an on position and a little red LED that should illuminate when in the on position.

On the other hand, I notice that the switches in the diagram are drawn as dpst switches, but only wired as spst. Correct? Could I order the 4 pin SPST LED switches from auberins.com (I don't see 6 pin switches for sale), or should I just use the 3 pin LED I have?

 

[doug293cz]

I do already have components in hand. The PID I ended up with is an AGPtek TA4-SNR

I don't believe the TA4-SNR has a manual power control mode, so it is not suitable for controlling boil vigor. To get manual mode, you need the TD4-SNR

Brew on

 

[doug293cz]

Reviewing the switches that came with the items I ordered, I see that the switch is indeed three pin. It is a simple toggle switch with an off position and an on position and a little red LED that should illuminate when in the on position.

Ok, if there is a light integrated into the switch, then it is a SPST, and the third pin needs to connect to neutral in order for the light to work when the switch is turned on. It also makes a difference which switch pin is connected to the power feed and which is connected to the load. If you get those backwards, the LED will always be on.

On the other hand, I notice that the switches in the diagram are drawn as dpst switches, but only wired as spst. Correct? Could I order the 4 pin SPST LED switches from auberins.com (I don't see 6 pin switches for sale), or should I just use the 3 pin LED I have?

Yes, Auber sells DPST lighted switches. Both the SW1 and SW16 are this type of switch.

Brew on

 

[WScottCross]

I don't believe the TA4-SNR has a manual power control mode, so it is not suitable for controlling boil vigor. To get manual mode, you need the TD4-SNR

Brew on

Correct. An alternative is the the DSPR110 from Auberins. Nice easy boil control with that.

 

[doug293cz]

Correct. An alternative is the the DSPR110 from Auberins. Nice easy boil control with that.

Yep, I already recommended the DSPR110 in post #6.

Brew on

 

[TheMerkle]

I am considering ordering the dspr110. Are there any additional items I will need to replace the PID in the provided diagram with the dspr110?

 

[doug293cz]

I am considering ordering the dspr110. Are there any additional items I will need to replace the PID in the provided diagram with the dspr110?

No additional components required. The DSPR110 hooks up to power, a PT-100 temp probe, and an SSR similarly to a PID. Just be aware that the connection locations (pin numbers) are different for each device type.

Brew on