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So you're wanting to replace switches 1 and 2 with pushbuttons?

NO/NC refers to the state that the circuit is in when it is deenergized. So a normally closed contact will be conductive (allow electricity though) when the power is off, whereas a normally open contact will act like a break in the circuit.

Then, if I'm reading the diagram right (a second opinion is advisable) you would wire them both up as NO so that they they complete the circuit when the button is pushed.

Most push buttons can be wired up either way depending on which contacts you attach the wires to, and should come with a diagram to show you which contacts are which.

As for the safe-start I have no clue on that one. I've never looked at that circuit before.
 
Also, are they latching buttons (do they click when you push them?) or are they momentary switches (go back to their original condition when you let off of them)?

If they are not latching buttons, you'll need to add relays to make the circuit work.
 
The way it is drawn insinuates that switches 1 and 2 are DPDT switches wired Normally Closed (not sure why though.. ) and switches 4 and 6 are SPST switches 1(NO).

SW1 will have to be rated for roughly 20A and SW2 for about 10A or so given the element wattages. (these aren't exact, just going off the top of my head here)

IMHO and FWIW, don't switch a load like that with a toggle switch. Throw a mechanical relay in place of those switches (1&2) and switch the coil of that relay with a SPST 1(NO) switch. It's much safer and your components will last longer.
 
I'm looking at the Momentary Illuminated switches that Auber offers. Thanks for clearing up the NO/NC for me. I think I might have to look at one of his other diagrams to figure out the safe start. Also, how do I use those switches if they are not 25amp? Do I need to use Contacters?
 
TedandMargeBrewing said:
The way it is drawn insinuates that switches 1 and 2 are DPDT switches wired Normally Closed (not sure why though.. ) and switches 4 and 6 are SPST switches 1(NO).

SW1 will have to be rated for roughly 20A and SW2 for about 10A or so given the element wattages. (these aren't exact, just going off the top of my head here)

IMHO and FWIW, don't switch a load like that with a toggle switch. Throw a mechanical relay in place of those switches (1&2) and switch the coil of that relay with a SPST 1(NO) switch. It's much safer and your components will last longer.
Click to expand...

+1 on isolating the load from the user operation. I was going to do the same thing and just incorporate heavy duty switches but after reading Kal's build articles I decided it was best to switch a 120v low-current coil than a 240v 24-amp load.

And back to the OP, if it helps, consider it this way: Most switches are like light switches. You flip it to "on" to complete the circuit. This is a NO maintained switch.

NC is a "kill switch" for lack of a better term. Flipping it cuts the circuit.

Momentary switches are only in the switched state while they are held there by the operator. These are used for things like reset switches.
 
MI_Dogman said:
E-Brewers,

How do I know if I need switches to be 2 (NO) or 1(NO) 1(NC)?

- Dogman
Click to expand...

NO-NO is for switching BETWEEN two different circuits. I would think you'd actually want a three-position NO-OFF-NO switch so there is an in-between off setting where neither circuit is compete.

Most on-off switches are NO maintained (normally open, switching closes the circuit, like a light switch).

I'd also recommend Kal's excellent site linked above, and the idea of incorporating mechanical relays between the switches and the load. You really shouldn't be switching high-current with a user-operated switch.
 
This is all helpful!! I'm trying to get this build going and I basically have the panel to build as the last challenge. BUT, I want to do it right and safe.
 
MI_Dogman said:
I'm looking at the Momentary Illuminated switches that Auber offers. Thanks for clearing up the NO/NC for me. I think I might have to look at one of his other diagrams to figure out the safe start. Also, how do I use those switches if they are not 25amp? Do I need to use Contacters?
Click to expand...

Then like Silver and Ted said, you'll want to throw in a pair of high-load 120V relays in place of those two toggle switches. Wire them both to NO, and wire your pushbuttons in to only regulate the supply power to the relay. It is certainly safer to do it that way.

There IS a way to wire momentary switches to make relays change state, and stay that way until they are turned off by another button, but it's far easier to just buy latching buttons IMO.
 
If you wanna use momentary switches, you will have to used a relay to "latch" that input on. Unfortunately you will have to use another switch to turn it off and deenergize the latched input. If you do want to use illuminated push buttons, just get the kind that are self latching. Push on/light on, push off/light off. Easy peezy.
 
SilverZero said:
NO-NO is for switching BETWEEN two different circuits. I would think you'd actually want a three-position NO-OFF-NO switch so there is an in-between off setting where neither circuit is compete.

Most on-off switches are NO maintained (normally open, switching closes the circuit, like a light switch).

I'd also recommend Kal's excellent site linked above, and the idea of incorporating mechanical relays between the switches and the load. You really shouldn't be switching high-current with a user-operated switch.
Click to expand...

That is certainly true if a single switch is operating 2 separate circuits, but I think the OP is operating 2 circuits with 2 switches here (unless I'm misunderstanding something). So you would want both switches NO until that contact is closed by the user right?

So you would basically have 2 separate ON buttons that latch when they are pressed and energize the relays. Then when pressed again, they deenergize the relays and shut the system(s) off.
 
TedandMargeBrewing said:
If you wanna use momentary switches, you will have to used a relay to "latch" that input on. Unfortunately you will have to use another switch to turn it off and deenergize the latched input. If you do want to use illuminated push buttons, just get the kind that are self latching. Push on/light on, push off/light off. Easy peezy.
Click to expand...


I'm going to go the latching route. Sounds much easier. I will just have to get a couple more Contacters.
 
TedandMargeBrewing said:
The way it is drawn insinuates that switches 1 and 2 are DPDT switches wired Normally Closed (not sure why though.. ) and switches 4 and 6 are SPST switches 1(NO).

SW1 will have to be rated for roughly 20A and SW2 for about 10A or so given the element wattages. (these aren't exact, just going off the top of my head here)

IMHO and FWIW, don't switch a load like that with a toggle switch. Throw a mechanical relay in place of those switches (1&2) and switch the coil of that relay with a SPST 1(NO) switch. It's much safer and your components will last longer.
Click to expand...

I did the editing to P-J's original schematic that was for a three element, three PID system, and turned it into a two element, two PID system. Link.

I'm not sure why P-J used DPDT switch symbols for switches #1 & #2 when DPST (NO) switches would have sufficed, or why he showed them in the activated position (for the elements.) The spec'ed switches (Mouser PN 633-8331F) are listed as DPST with 25A ratings, but no longer appear to be available.

I agree that using finger activated switches for high current, 240V circuits isn't the best practice, and should be changed to contactors activated by manual switches.

Brew on :mug:
 
So my next question is on the Contactors:

Should I just get Two 240v 30amp Contactors? Or

One 120v 30amp and One 240v 30amp?


The rims will be 2000w and the HLT/BK will be 4500w. It's a two vessel system in case anybody is wondering. I see the drawing says two 240v 30amp. I just want to hear opinions
 
MI_Dogman said:
So my next question is on the Contactors:

Should I just get Two 240v 30amp Contactors? Or

One 120v 30amp and One 240v 30amp?


The rims will be 2000w and the HLT/BK will be 4500w. It's a two vessel system in case anybody is wondering. I see the drawing says two 240v 30amp. I just want to hear opinions
Click to expand...

As long as you have 240V, you should use it for both the RIMS and HLT. So, get the 240V contactors. You can get less than a 30A contactor for the RIMS if it is significantly cheaper. But, if the cost is the same, might as well get two @ 30A.

Brew on :mug:
 
I built my panel using those push button illuminated switches. I'm at work and on my phone but I can tell you how I did it when I get home. Until then there is a thread on theelectricbrewery about those switches and I have a panel build thread there and I had to ask a few questions about using the push buttons.

I didn't use a "safe" start interlock, though and I think it will be challenging with those switches.
 

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