Electric Brewing - Control Panel Branch Circuits

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Bobby_M

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Side note: anyone think a dedicated "electrical" subforum makes sense in this equipment forum? Just thinkin.

So, I know this is going to opening a can of worms but that's fine. Let's go there.

Premise: The basic tenants of electrical safety say that the circuit breaker that feeds a circuit should trip before the wiring between that breaker and the load has a chance to overheat. Example, 26amp (planned) load on some 10/3 copper romex, should be fed off a 30amp breaker. If the actually load increases for some reason and it exceeds 30amps, the breaker trips so the romex doesn't burn up in the wall causing a fire. No argument there. It's even common sense. Branch circuits in a home wiring situation are typically dozens of feet long, if not even 100 feet and buried in the walls.

In practice: It seems like many electrical builds that involve a big control panel include a high amperage, large cable, main power connection. A lot of them are fed off a 4-wire, 50amp spa breaker panel. Of course none of the devices fed from the control panel represent a full 50 amp load so it involves branching. 30amp to each of potentially two 4500watt elements at a time and a little extra, couple amps, for pumps or whatever.

I see that a lot of builds include a rail and associated rail mount breakers for these branch circuits but it also adds over $100 to the build. Is everyone really that paranoid about overloading a 3 foot run of exposed cable that is used intermittently while its being supervised? Electrical codes are based on worst case scenario so let's talk about what that would be if two runs of 10/3 SJ are hard tapped off the 50amp main and run 3' to your vessel elements. I THINK in order for something bad to happen, the load on one of the branches would have to increase somehow to like 50 amps and hold there while the other branch was off. Even so, how long would that condition have to exist before the SJ cord self destructed? What exactly would cause a resistive load of typically 26 amps climb to only 40 or 50 amps and NOT a dead short? Of course, a short condition would trip the 50amp spa breaker before any of the branch wire was fried.

Am I talking out of my bung or are you following me? These aren't production breweries right, just a couple hours on the weekends.

Of course, this isn't advice so don't take it as advice. I'm just talking here.
 
I do not think internal breakers are necessary. I do think fuses are a good idea for protecting internal components and wires. So long as the system is designed properly, overload should never occur. If something goes wrong, you have the fuses, and if something really odd happens, the breaker should trip. I see no problem with standard branching.

Am I missing something?

Also, I think there should be an E-forum.
 
In building a control panel and supplying it with a single 240V feeder, we are "tapping" off that feeder to supply separate components. Providing fusing/circuit breakers on the tapped conductors will not provide additional protection for your feeder but will serve to protect the wiring and components after the tap is made.

Say you are using a 50A spa panel to protect your control panel feeder. In your control panel you tap the feeder with a #14 to supply power to your PID. Now should there be a fault in you PID nothing will stop the #14 wire from carrying the full 50A your feeder breaker is capable of.

As far as I understand the code, the above tap is legal without overcurrent protection as long as some conditions are met. The code section to search is 240.21 if you are interested.

Having said all that, I have no secondary fusing in my panel. I have it in a good enclosure with kill buttons if anything should go wrong and I feel safe using it.
 
I believe the breakers I used from automation direct were around 16 bucks each. The difference between those and fuses are probably negligible. Plus they give you a good wire connection point. If you’re going to spend the money to build a system it seems like the wrong place to save a penny.

Mike
 
Side note: anyone think a dedicated "electrical" subforum makes sense in this equipment forum? Just thinkin. ...
I think it is an excellent idea.

Re: The balance of your topic, I'm with you 100%. The sensitive devices (PIDS et.al.) should be fuse protected anyway. As a side note, have you ever seen the guts of an electric range? No breakers, no fuses - fed from a 50 amp mains circuit. Elements fed (240V) using #14 or #12 wire depending. Lighting fed with #16 wire. (the outlets do have fuses or breakers though)

Interesting topic. I expect to see lots of info on this one.

Thanks.
P-J
 
I think people get too hung on "code". I had an electrician over this spring to talk about splicing into my stove line to add a plug in the garage for my brewery. I asked about code, he said, it's your house. You're allowed to do whatever you want as long as you run the appropriate wire size for the load.
 
I think people get too hung on "code". I had an electrician over this spring to talk about splicing into my stove line to add a plug in the garage for my brewery. I asked about code, he said, it's your house. You're allowed to do whatever you want as long as you run the appropriate wire size for the load.

What works and what is good practice are 2 very different methods.
 
I agree. Just putting that out there for the code nazis. We're not wiring warehouses full of CNC machines and boring machines. I am building an electric brewery myself. Like Bobby mentioned. These are monitored systems that get brought out for a few hours on the occasional weekend. I agree we need to be safe with stuff, but code enforcement is way over drilled in the forum.


I agree about a subforum. Electric systems are very popular these days.
 
The only breaker I use is the one in the house's panel. I do use a fuse to protect my PID.

DSC05058.jpg
 
I think people get too hung on "code". I had an electrician over this spring to talk about splicing into my stove line to add a plug in the garage for my brewery. I asked about code, he said, it's your house. You're allowed to do whatever you want as long as you run the appropriate wire size for the load.

I'm not exactly for or against adherence to code, but I have to wonder what the local inspector would have to say about 300,000 BTU worth of burners cranking in the garage.
 
I think people get too hung on "code". I had an electrician over this spring to talk about splicing into my stove line to add a plug in the garage for my brewery. I asked about code, he said, it's your house. You're allowed to do whatever you want as long as you run the appropriate wire size for the load.

I'd suspect that your "electrician" isn't to hip with the realities of insurance and law. If you do something that is not to code in your home and burn it down you can be sure the insurance company will not pay you if they know about it. They will look for any reason not to pay a claim.
 
I got an idea for a fuse: if anyone can find the old fashioned screw in fuses that went into a light bulb socket thread, you could use one in combination with a porcelain light bulb base on the hot feed for an inline fuse. Those things are pretty antique and not codeworthy but if they're available then that would work.
 
I'd suspect that your "electrician" isn't to hip with the realities of insurance and law. If you do something that is not to code in your home and burn it down you can be sure the insurance company will not pay you if they know about it. They will look for any reason not to pay a claim.

My electrician is the owner and master electrician of the largest commercial electric company in my town. I'd say he has a very good grasp on code and I'll take his advice over anyone on this forum any day. :mug:
 
An electrical sub-forum is a *GREAT* idea! (Says Kal as I sit here writing up how my control panel was built for my new www.TheElectricBrewery.com website). ;)

Back on topic:

I feed 10/3 (30A/240V) into my control panel. A 30A breaker sits in the house breaker panel to protect the wiring in the house that goes to the control panel. A GFCI sits in the cord that plugs into wall socket into the which the control panel plugs. This protects the brewer.

I don't feel that additional breakers are neeed in the control panel, but I do use a single 7A fuse in a holder ($2 total) inside the control panel. It's placed between one of the HOT (30A/120V) inputs to the box and the 15A/120V hot bus used to power my PIDs, lights, pumps, etc. Normally no more than 3-4A should be flowing into this bus.

I don't understand why you'd use a more expensive resettable breaker for this as it should only trip if ever there's a catastrophic failure of some sort. If my 7A fuse blows (worth 10 cents) it's because something failed completely and needs to be repaired. You don't just reset the breaker and replace the fuse.

This is different than a house breaker panel. Resettable breakers make sense in that sort of setup since you never know how many things may be plugged into a circuit so the chance of tripping a circuit breaker are much greater. With our control panels that is not true since they're closed systems.

Kal
 
Kal
a) freaking LOVE your rig and your site, I think I've been clicking refresh everyday for the control panel build. :mug:
Thanks! I'm about 20-30 hours into writing the control panel build information. Probably have another 40-100 hours to go. There's *LOTS* of information here so it'll likely be split into 2-3 parts.

Kal
 
Why would anyone ever tell an insurance company the truth? :fro:

Thing is after your house burns down there will be a fire inspector that comes around to determine how and where it started. It will all be covered in his report.
 
I think people get too hung on "code". I had an electrician over this spring to talk about splicing into my stove line to add a plug in the garage for my brewery. I asked about code, he said, it's your house. You're allowed to do whatever you want as long as you run the appropriate wire size for the load.

As a licensed Professional Engineer who deals with code on a daily basis, I would not let that electrician anywhere near my house. Of course, I also would probably do 90% of all wiring in my house myself.

You are most certainly NOT allowed to do whatever your want as long as you run the appropriate wire for the load.

In your specific case, you are allowed to tap the stove line provided:
1 - the splice is made in an enclosure.
2 - the splice is made with wire rated for the ampacity of the circuit breaker protecting it OR the tap is less than 10 feet in length and terminates in appropriate overcurrent protection(in general, there are actually several provisions for taps based on various circumstances, but the 10 foot tap rule is the most common situation)

Code is often overstated and overkill for many things, but one place I would not mess around is on overcurrent protection. Get too crazy with that and you've got a fire waiting to happen.
 
Call me paranoid, but I would never run undersized wire without protection. As you've probably seen in my build thread, the 6 gauge main supply is protected by the 50A breaker in my main panel. The 10 gauge wires for my elements are protected by 30A breakers in the control box. 14 gauge is protected by 10A breakers in the control box.

We're talking about a lot of amperage, 240V circuits and liquids. Yes, it's a short run. Yes, I'm supervising it. But I still don't want the wires melting because they're not protected by an appropriately sized breaker. The breakers were $16 each for the 30A and $8 each for the 10A. So $48 is cheap insurance when amortized over the time I'll be using the rig.

Edit: the DIN rail was $6.50 for 2 meters worth.

For the record, codes never entered into my thinking. Just protecting wires from burning up in a worst case scenario.

-Joe
 
I don't blame you one bit - I would probably build it the same way. Code does allow for undersized tap conductors in certain situations, however - not that it is recommended practice.

If I were doing it, I'd probably buy a little 60A 6 or 8 circuit load center, mount it to my brewery structure and fill it with 30A/2P and 15A/1P breakers, running all my wiring back to that point.
 
As a licensed Professional Engineer who deals with code on a daily basis, I would not let that electrician anywhere near my house. Of course, I also would probably do 90% of all wiring in my house myself.

You are most certainly NOT allowed to do whatever your want as long as you run the appropriate wire for the load.

In your specific case, you are allowed to tap the stove line provided:
1 - the splice is made in an enclosure.
2 - the splice is made with wire rated for the ampacity of the circuit breaker protecting it OR the tap is less than 10 feet in length and terminates in appropriate overcurrent protection(in general, there are actually several provisions for taps based on various circumstances, but the 10 foot tap rule is the most common situation)

Code is often overstated and overkill for many things, but one place I would not mess around is on overcurrent protection. Get too crazy with that and you've got a fire waiting to happen.


Generally, I agree.

The NEC is basically a safety manual. It provides minimum requirements for a safe electrical system. You can always bump up your level of safety or choose to completely ignore it and hope for the best.

As far as wiring in your own house, you CAN do whatever you want. No one is gonna come look at it unless you pull a permit or they are coming to investigate a fire/insurance claim. But as a contractor myself, I would not give out that advice.

The term "code nazi" was brought up earlier. I assume this is directed at either the OP or myself as I belive we both mentioned it prior to that post. This is my take: My system is not "to code" in all respects but I am experienced, educated in and respectful of electrictiy. If you are not all of the above, follow the code at a bare minimum and you will be safe. Stating code to help others to build a safe system does not seem very nazi-like to me:mug:
 
For those looking for high amperage fuses... I highly suggest panel mount fuse holders McMaster #7055K18 with midget fuses sized for the conductors you are using. The power feeding your panel should already be coming from a breaker rated for the power cord. At half the price it could be worth it for some... like me.
 
As a licensed Professional Engineer who deals with code on a daily basis, I would not let that electrician anywhere near my house. Of course, I also would probably do 90% of all wiring in my house myself.

You are most certainly NOT allowed to do whatever your want as long as you run the appropriate wire for the load.

In your specific case, you are allowed to tap the stove line provided:
1 - the splice is made in an enclosure.
2 - the splice is made with wire rated for the ampacity of the circuit breaker protecting it OR the tap is less than 10 feet in length and terminates in appropriate overcurrent protection(in general, there are actually several provisions for taps based on various circumstances, but the 10 foot tap rule is the most common situation)

Code is often overstated and overkill for many things, but one place I would not mess around is on overcurrent protection. Get too crazy with that and you've got a fire waiting to happen.
I agree. Perhaps it was just him tell me this because we had already talked about the project and I mentioned the run I was doing with the conduit and junction box. So perhaps he was saying "I" can do what I want because I knew what I was doing.
I guess my reply came from frustration of seeing several threads (and now this one) drove into the ground with code discussion when they guy asked a simple question that had to do with electricity. All of a sudden everyone started quoting their NEC book.
I will trust this guy to do work in my house despite anyone else's opinion. If he didn't know what he was doing he would have ran a successful Electrical contractor business for the past 30+ years.

I'll take someone who knows application over someone who can quote a book and theory without knowing the real world reason why.

This is not a direct stab at anyone personally.
 
Code are minimums of safety. Code are developed because somebody did something stupid and cost people lives. Nothing wrong with code.
 
Code are minimums of safety. Code are developed because somebody did something stupid and cost people lives. Nothing wrong with code.

I agree. Its not like you have to listen to a bunch of guys and girls online telling you what the code is, but I have a hard time being angry at people trying to make a situation safer. Frankly, I have done a lot of crazy wiring stuff to make things work in my time, and some things I see here make even me cringe...

It is more expensive to build things the right way, but IMO it is really worth the extra trouble and expense. For an extra $150ish per one of these builds you can at least get some fuses and make sure you have a GFCI installed. (Yes, I know the GFCI may or may not be parts of the code, but in our instance it just seems like a good idea...).
 
+1 on the sub-forum.

The reason you use a smaller fuse/breaker is to be able to use thinner wires, the smaller fuse/breaker will not provide any additional protection to your PID or other equipment.

If you want to protect your PID you're better of using surge protection.

With installing multiple fuses be careful that different parts of your setup can still be hot even do all your lights and PID's are off.
 
Call me paranoid, but I would never run undersized wire without protection. As you've probably seen in my build thread, the 6 gauge main supply is protected by the 50A breaker in my main panel. The 10 gauge wires for my elements are protected by 30A breakers in the control box. 14 gauge is protected by 10A breakers in the control box.

We're talking about a lot of amperage, 240V circuits and liquids. Yes, it's a short run. Yes, I'm supervising it. But I still don't want the wires melting because they're not protected by an appropriately sized breaker. The breakers were $16 each for the 30A and $8 each for the 10A. So $48 is cheap insurance when amortized over the time I'll be using the rig.

Edit: the DIN rail was $6.50 for 2 meters worth.

For the record, codes never entered into my thinking. Just protecting wires from burning up in a worst case scenario.

-Joe

I won't too adamantly defend my position of "not really necessary" on the branch breakers that you've installed. Given the prices I found for similar breakers, I wouldn't do it but at your pricing I would consider it if not go the fuse route. What I would like to chat about is what situation would cause the 10/3 SJ wires to overheat but still stay under the 50amp total load on the main supply? I'm not saying you should know, but I'm wondering if anyone can speculate. It's a narrow band between the amperage that would cause physical damage to 10/3 (what, realistically 40+ amps or so) and the 50 amps on the main. Something really odd and really specific would have to happen to get the element to draw 48amps.

Again, not argumentative at all, just fueling some conversation.
 
10/3 is rated to 55A??? That wire is protected by the 50A breaker. The internal breakers and/or fuses are for the branch circuits. I don't think any standard situation would cause a failure of the 10/3 power wire as long as a 50A breaker was somewhere in that circuit...
 
I won't too adamantly defend my position of "not really necessary" on the branch breakers that you've installed.
Nor was I attacking your position :) Just stating mine.

I don't know what situations can cause a sustained 40A load on a 30A circuit. Maybe my heatstick element chafes and grounds to the pot, but isn't enough of a dead short to trip the breaker. Maybe something breaks down inside the element, lowering its resistance just enough to draw 49.4A continuously and melt the 10ga wires. /shrug

I do know that even if the chances are slim, I don't want it to happen to me. I've put enough time and money into the system (there's a spreadsheet I should never have started ;)) that skimping on safety for $50 would be silly.

YMMV.

-Joe
 
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