Advice on control panel wiring

After looking at several PJ wiring diagrams I came up with this. (Thanks PJ for the examples it made making this a lot easier.)

Please comment on what I have incorrect here as it just does not seem correct for some reason.

Thanks in advance..

 

What's the yellow button? An emergency stop implemented by forcing GFCI to trip?

 

The only comment I would make is that the e-stop (if that's what it is) is going to cause 7.2 watts in your 2k resistance. Probably not really an issue that this is over spec of the resistor because the GFCI will trip pretty fast, but something to think about.

The only other thing I can think of is that you might want a very small fast acting fuse to protect the PIDs and some small slow-blow fuses protecting the pumps.

 

Yes. The circuit is in place to trip the GFCI in the main panel. It is setup as an "Emergency Stop" that provides 0.06A of ground fault current.

Come on Walker, Do you REALLY think that your calculated 7.2 watts of power drawn will damage the resistors? Really? Come on. We are talking about a millisecond here.

The fuse illustrated to protect the PID is a "1A Fast Blow". Do you have a suggestion for some other device? How about a link?

Re: The pump. Say you have a pump that you set up to plug into a 120V outlet. (Hey, it's a simple system, Ok?) Would you add a fuse in line to protect the pump? I think not. The diagram shows that the pump is protected by a 15A breaker in the panel. Now what?

Walker, I sincerely apologize for a somewhat curt answer. Sometimes we tend to over think 'stuff'. I'd love to have the opportunity to talk with you about "stuff". I think it would be a fun conversation.

HempelNet,

Once you come up with the 'final' plan and would like a diagram for your records, I'd be more than happy to draw it out for you.

BTW, Thank you for honoring my diagram. I have lots more.

Paul
(P-J)

 

No, I don't think it will be a problem, and that's why I specifically said "probably not really an issue".

No other suggestion. I simply overlooked it when I looked at the diagram the first time.

If I were just plugging the pump into the wall, then... no... I probably wouldn't have a fuse there because it would be a PITA to build a box with a fuse and receptacle or whatever.

But... if given the opportunity to spend $3 for fuse to put into a box I was already building to better protect a piece of equipment that cost over $100, then I would ABSOLUTELY do it. No doubt about it.

Apology accepted.

 

I must have accidentally erased the last part of my post (in response to the "over thinking").

I am 100% certain that I over think things. It's in my nature and what I get paid to do when I am disguised as a mild mannered engineer.

e-stop resistors : not a big deal

PID fuse : already there. I didn't see it.

Pump fuse : a well spent $3

I do have to ask you, P-J: why suggest a fuse for the PID (a $45 item) but not for the pump (a $125 item)?

 

You made me laugh. thanks.!
The PID can be wired wrong in a way that it can easily be damaged. No so with the pump. The pump is most commonly wired to a 15A circuit without issues. Just to mention: The pump was designed for circulation of water in a heating system - not for brewing. It is most commonly wired to breakers that protect the wiring. (15A - 14 gauge wire)
I do see your point however.

Thanks for the added post.

 

I saw no mention of what pump he was using, so I made no assumptions.

 

I've never seen the e-stop that trips the GFCI is this common practice? I think I'd like to add the to mine.

 

Congrats!!!

Uncle.! You win!

 

It is a circuit that I came up with to simplify an emergency power off. In an emergency, you want to kill all power. I designed this to trip the mains GFCI breaker in that event. Simple but VERY effective.

It depends on the power having a mains GFCI breaker to your brew rig. It acts just like pushing the test button on the GFCI breaker. A small leakage current does the task.

 

BTW: that's a very clever idea. A hell of a lot more effective/cheaper/simpler than other e-stops that I've seen on here. I was just out rummaging through a box of random electronic stuff to see if I had a momentary switch to use for one myself.

 

Just another idea ... Why go through the effort of tripping the GFCI when you could just put in a shunt trip breaker? My 2 cents ... Also in the vane of over kill why not put in a master forced coil that the mains runs through and drop the coil through the e-stop?

 

I think the idea was to cut power all the way back at the source by pressing a button on the brewery panel, and spend about $1 to do it.

 

I'm a believer in PJ's E-stop!

works good lasts long time!

 

Thanks so much for the sanity check since I am in no way an EE just a brewer with an obsession to build this system!

I already have ordered:
SS stand from BrewersEquipment (Should be delivered in 2 weeks)
RIMS Tube from BrewersEquipment
PIDS / Relays / Probes

Currently have:
2x March 809 pumps with chugger SS heads
All the fittings (after several orders )
Jays False Bottom
Keggles

Still looking for:
Correct elements
Switches / Fuses

Yes P-J I would love a refined design drawing if possible please.

 

Will do.

 

HempelNet,

How is this?

Click on the image for a full scale diagram.
BTW - it is printable on tabloid paper - (11" X 17" sheet)

 

Perfect! Thanks again, now to order some parts to get this baby started.

Cheers

 

Exactly.

The option with the shunt trip breaker would set me back way over the realm of reasonable >> at the least $125 just for the breaker? Plus the breaker control circuits? And then the issue of GFCI protection? - ????

WOW.!!

 

Great! Now you need to let us know what you are doing and make this your awesome build thread..

Wishing you great success.!!

Please let us know how it turns out.

P-J

 

P-J

Is this 1k-ohm 1W 5% Metal-Oxide Film Resistor (2-Pack)
the correct resistors ?

Thanks for the idea, something I need to add to my build.

 

That will be A-Ok. All that matters is a small leakage current to ground so that the GFCI breaker in your mains panel trips.. It is just like pushing the 'Test' button on the GFCI breaker, after all.

 

In a professional environment it would never pass. At home it would work just fine, but would I ever do it, no.... I just stick to using a hold in circuit, hit the estop and it kills the circuit. My breaker is within arms reach of the panel anyways.

So no need for me to intentionally (but with a resistor) ground the circuit. :cross:

 

The idea of tripping the GFI with a small resistor is brilliant! Nice thinking. I am just throwing this out for the fun of it: My spa panel has a white coded 50A breaker, it trips at 4mA IIRC. I read somewhere on the web (from Germany I think) that this is the recommended GFI current for human protection, higher currents are more intended for property protection. It seems that a hot tub is perhaps the worst imaginable situation to have a ground fault, so it better trip at such a low current. Using a 27KΩ resistor to bleed one of the legs to ground produces 4.4mA ground current which should make the GFI trip. This produces only 0.53W of heat in the resistor, so a 0.5W resistor should be good enough as long as it trips the breaker. Even a 1/4W might be good enough given the short trip time. One would have to test this first of course. I did not think of this so my E-stop breaks all control currents to make the relays and contactors drop out.

Edit: I think white is 1mA, not 4mA. Even better.

What is the thinking on protecting the PID with a small fuse? I am not trying to be a wiseass here, just curious what your thoughts are. Let's say we’re using a PID with an SSR output. What could go wrong so that you would want the fuse to pop? My PIDs are fed from a master 5A circuit breaker, and my thinking is that I am protecting the wires should the PID have a catastrophic failure and try to smoke the 14 awg wires. I think that if a PID starts to draw excess current then it is already broken and beyond salvage. No?