2x 4500W elements?

So, I've been scouring the electrical threads for months now, playing out various scenarios that I'd like to consider for upgrading to a 10+ gallon all-electric brewhouse. There is still plenty I have to consider, so I'm not jumping into this quite yet, but wanted to see if I could clear something up.

Here's the scenario: I have a small room in my basement that I'm converting into the brewery (at SWMBO's suggestion no less!) and will only use electric in it, nothing gas. So, no matter what I do, there will need to be fresh electrical ran to the room. Safety is obviously most important, so I'm heavily leaning towards the Spa Panel for my GFCI since it seems to be the best for both wiring plus price, especially if I want to use 120V and 240V in the same control panel. Because of this, I'm leaning towards just running 6/3 wire from the panel and putting a 50A breaker in there so it is 50A all the way through. I plan to use 5500W elements or 4500W in both the HLT and BK, but plan to use a cooler for my mash so I won't be recirculating like HERMS/RIMS.

Where I'm a little stuck is, on one hand, 50A seems overkill if I only run one element at a time, as I've seen most people use 30A service to achieve that. Obviously with 5500W elements I can't run both at the same time on 50A, but I just wanted to see if someone could clear this up for me. I haven't seen anyone mention it in all of my searching but I assume there is a reason it hasn't been done. Is there any reason you couldn't put two 4500W elements on a 50A circuit? From doing the math with the spreadsheet I found on here, 9000W should only add up to 37.5A, which is within the 80% threshold it seems. Again, since this hasn't been done I'm sure there's a good reason not to, but since I can't find anyone mentioning it, I'm not sure if it just hasn't been tried either. I would like the convenience of running both at once since I do often do back-to-back batches, but it isn't an absolute must, just seems possible in this case. Since I won't be doing RIMS/HERMS either, the only times the pumps will be used is for transferring from one vessel to another, even then, the math seems to add up that it shouldn't be an issue then either.

Did I miss something perhaps? The spreadsheet was straight forward, I just punched in the numbers and it claims it should work, but again, I just feel like I must be missing something. I'm fairly familiar with DC electronics and 120V AC stuff but this is a little above me. No worries, the wiring in the household will be done professionally and otherwise I have a friend who's more familiar with 240/120 to help on the other details as they come up, but I'm just curious if this seems possible or even a good idea. Sorry if this has been posted somewhere already, I've been hunting for a while and haven't found something quite like this scenario, so feel free to point me elsewhere if I missed it. Thanks!

The 80% "rule" does not apply to your situation. No way. Your 50A 240V electrical run will be going to a single outlet. With that said, 2 5500W elements, a pump and your controller will draw less than 50A.

You are good to go.

P-J

Pardon my ignorance, but why doesn't it apply in this situation? I guess I'm just surprised that no one else seems to have gone this route, as often as I've heard people bring up wanting to be able to run two elements at the same time. I know in some cases it is because they are on an existing 30A circuit. The idea I have in mind is the 50A circuit will run the whole way through the spa panel into the control panel, at which point I plan to make the circuitry similar to the diagram I've seen you post before, only I'm trying to think through re-working it to use 2 PIDs, etc. (or possibly just 1 PID and a PWM for the BK, if that seems reasonable to do). Again, I'm fairly familiar with electronics, but I'm just very cautious when it comes to dealing with 240V and this much amperage, so I want to make sure I have all bases covered. This project is still in the works, so I'll definitely be posting a build thread once I get everything more hashed out, but I figured it would make sense to clear this up before planning it into my build and finding for whatever reason it's a bad idea. Thanks, I definitely am glad to hear this sounds more feasible than I was first guessing!

The specific NEC rule only applies to a multi drop circuit where multiple outlets are wired to a single feed. It also applies only to the designer & the electrician doing the wiring. It does not apply to the home owner. The primary reason for the implementation of this rule was for the planning of the outlet layouts in kitchens and how portable appliances might be places on the counter. Because of it, refrigerators generally have their own outlets today.

As a home owner - you should have no concern about this NEC rule.
You can easily run 2 5500W elements on a 50A 240V feed.

Here is an example of a possible setup that might interest you.

As always - click on the image to see a full scale diagram that is printable on Tabloid paper 11" x 17":



I hope this helps you.

P-J

Holy cow dude, you rock! :rockin: Even the diagram, you are awesome! That's actually along the lines of what I was picturing, except you even included the stuff I haven't planned out yet (resistors, etc). Thanks a ton, I'm definitely getting excited about this project now, it seems a lot more realistic and a lot closer already! Thanks again!

It's exactly what I plan to do, but when I mean plan, I mean, it is my high level intention at this point. I'm going to put two 5500w elements in the HLT and two 5500w elements in the BK. I'll use an interlock so that I can only run either two in the HLT, two in the BK, or one of each at the same time. Yes, it's pure overkill but in the end it's for time savings and scalability. Right now it's a 10 gallon system but if I ever go to 15 or 20 in the future, it's just a vessel change out not a full system overhaul.

Bobby_M said:

It's exactly what I plan to do, but when I mean plan, I mean, it is my high level intention at this point. I'm going to put two 5500w elements in the HLT and two 5500w elements in the BK. I'll use an interlock so that I can only run either two in the HLT, two in the BK, or one of each at the same time. Yes, it's pure overkill but in the end it's for time savings and scalability. Right now it's a 10 gallon system but if I ever go to 15 or 20 in the future, it's just a vessel change out not a full system overhaul.

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Bobby,

I'm going to have to think about that for a while and see what mind jumps I can do with it. Give me a few days (and then remind me if I don't). That's so I don't just let it go. (Getting old sucks big time!) It should be intriguing to see how I can come up with a good interlock. Hmmm..

P-J

worstbrewing said:

Holy cow dude, you rock! :rockin: Even the diagram, you are awesome! That's actually along the lines of what I was picturing, except you even included the stuff I haven't planned out yet (resistors, etc). Thanks a ton, I'm definitely getting excited about this project now, it seems a lot more realistic and a lot closer already! Thanks again!

Click to expand...

I'm please that I could help you. Let us know how it is going for you.

P-J

P-J that diagram shows the SSRs as 110V. Is that correct?

weirdboy said:

P-J that diagram shows the SSRs as 110V. Is that correct?

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No. The SSRs are switching one leg of 240V that is being delivered to the elements through switches (Switch #1 & #2)

Keep in mind that the SSR is nothing more than an electronic switch.

HTH

P-J said:

Bobby,

I'm going to have to think about that for a while and see what mind jumps I can do with it. Give me a few days (and then remind me if I don't). That's so I don't just let it go. (Getting old sucks big time!) It should be intriguing to see how I can come up with a good interlock. Hmmm..

P-J

Click to expand...

Don't rack your brain too much on it. My first instinct is to use a 3 pole double throw contactor. The feature being selected for is which vessel gets "supercharged" heating at any given time. Two poles are selecting which element is getting fed by the supercharge SSR. The 3rd pole is to select which PID output signal is feeding that SSR. Normally closed would have the HLT selected. I think that would work. Any ideas why not?

I just designed a system I'm gonna build when I get home from Afghanistan that is similar to what you describe Bobby. Three keggle HERMS with two 5500w elements in the HLT and two in the BK. Meant to be scalable to 1bbl one day, and I also want to be able to bring 14 gal to a boil in under 15min. I'm using DPDT relays and a rotary selector switch to hardwire select any possible combo of only two at a time to stay under the 50a service. Only uses two SSRs also.

P-J said:

No. The SSRs are switching one leg of 240V that is being delivered to the elements through switches (Switch #1 & #2)

Keep in mind that the SSR is nothing more than an electronic switch.

HTH

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Sorry, I haven't had a chance to look at this stuff since Friday but I think I might be a little confused with what you mean here. I see the power going through the switches, but with one leg going through an SSR, won't one leg still be hot when the switches are on yet the SSR is off? Should I consider 2 SSRs each, or an SSRD? Again, 240V is not my expertise, so I could be thinking of it wrong, just want to better understand.

The element will not be a completed circuit without both legs feeding it. So it will not draw a load unless both legs are completed. That is why just one leg goes through the SSR, essentially your are just controlling the duty cycle by switching one leg off and on.

Gotcha, I guess what was throwing me off is I recall people talking about running a 240V element with 120V (obviously not at full power) and my assumption was that it would be a similar scenario here if one leg is switched on but the other is not. Again, I'm used to working with 120V more than anything so I'm just trying to make sure I understand this. Thanks!

You can use 240 elements on 120. You just have to use a neutral.

With 240V split phase power you have 120A and 120B. Which means when 120A is Positive, 120B is Negative (Sorta in lamens term).

Here is a picture of a sine wave that is 180 out, just like your 240 split phase.


Well call the blue wave 120A and the pink 120B. 240 split phase power does not need a neutral to operate and the ground is just a safety. Same thing with any multiple phase power. You get your voltage potential when the phases are opposing. This is why using math 120 - (-120) = 240. Many people would think that 120 and -120 would cancel each other out. But in the case of math and real life it does not. Since they are 180 degree out, at ANY given time they will always be exactly then same voltage just opposite polarity.

Voltage is potential between 2 points. It is not voltage against ground(0V). Voltage against ground is just 1 case of 2 points, but not the definition. You kinda have to unlearn when starting to learn multiple phase power. Your potential is now between the phases AND the ground.

Gotcha, that actually makes a lot of sense how you explained it. I've always heard the term multi-phase but never knew it was that complex. Thanks! I also realize my comment earlier regarding the SSRs has been beaten into submission all over the place here, so I'll leave that alone lol.. Ultimately, I'm understanding that it doesn't make sense to rely on an SSR for each leg just for the feeling of both being "safe" anyway, since you should be killing the power via the switch anyway, and obviously wouldn't be unplugging, etc with any of that live. So, I feel safer about it now, thanks!

One more thing that has had me scratching my head a bit, more so just on the side of safety, etc. is, what does everyone do when done using a control panel like this? Do you rely on the E-Stop as a power switch (my gut says no), do you just flip the spa panel GFCI every time you're done (gut also says no), or install a separate box with a pull switch to kill the power? Just curious, as it's something I've not seen specifically addressed and of the obvious places to kill power, I'm unsure if its a "best practices" kind of thing or not. Thanks again!

If you really want to get indepth look up center tap transformers and it should explain all of it.

EDIT:: Heres a good link.
http://en.wikipedia.org/wiki/Split-phase_electric_power


But I always shut off the breaker, just to be on the safe side. Plus its like 3 feet from my brewery, so its no issue.

Gotcha. The breaker itself will be at the complete opposite end of the house (it's a row home, so I wanna say 40-50 feet at most) but the spa panel will be smack next to the control unit more or less (still planning placement of everything out, its a small room so it takes some thinking to best utilize the space). So, from what you're saying, would flipping the spa panel breaker off be ok? I don't see it causing any problems, I just realize over time it could lead to wearing out the GFCI possibly.

Slightly off topic, but attached is a google sketchup I've done to get a feeling of placement, etc and to show how small the room is. If you have any thoughts on placement or anything feel free to chime in. The control unit is on the wall nearest the top, with the switches, etc coming off of it. Next to it on the left is a mock-up of the spa panel just to give an idea on size, etc. Again, neither of these are necessarily final, just the current idea I have for trying to squeeze a brewery into this small room.

Edit: also, thanks for the link! This is definitely far more interesting than I had imagined, and certainly can't hurt knowing more in the process of getting this built!

I'm sure just killing the spa breaker is fine.

You could use PJ's estop circuit which, intentionally trips the gfci.

Yeah, that's true. Either way to turn it back on the GFCI will need reset, I suppose. At first I actually wasn't sure how the E-Stop was supposed to work until it hit me that it isn't stopping any one thing in the control panel but rather tripping the GFCI, which definitely makes sense. Thanks again for clearing everything up. I wanted to make sure I properly understood everything rather than just try to hook it up blindly, so I'm feeling a lot more comfortable now.

Don't mean to invade this thread but this is the exact same setup I'm looking to eventually build into but was hoping to start with getting my 1 keggle converted to electric for my extract process before the winter starts. P-J I love your diagrams and have seen your excel sheet writeups with parts and links. Can you provide an excel sheet for the parts shown in that diagram and then I will down grade the part numbers for the 1 keggle setup I currently have and then will eventually double the parts once I'm ready to go AG.

So, if I'm understanding some of the earlier posts correctly, a 50 amp breaker would be just fine to use for a system. I have a 50 Amp protected breaker in my main panel now that was used for a spa by a previous owner of the home. I am considering building this - http://www.pjmuth.org/beerstuff/images/Auberin-wiring1-a17a-SYL-2352-5500w.jpg - (thank you P-J). I was under the assumption that I had to drop the 50 Amp breaker down to a 30amp first. I talked to an electrician who said they could use the existing breaker, install a small conversion box to drop it to 30 amps, and then install a 30Amp outlet for me (about $200 worth of work). Is this necessary? or am I better off just having a 50amp outlet installed?
This is all beginning to confuse me greatly.

The breaker is meant to protect the wiring so as long as the run to the control box can handle 50 amps, you're good to go.

(deleted)

Whoops, just realized my post was completely irrelevant! I should have read the beginning, this was a thread I was actually talking about!

sgoncalves said:

Don't mean to invade this thread but this is the exact same setup I'm looking to eventually build into but was hoping to start with getting my 1 keggle converted to electric for my extract process before the winter starts. P-J I love your diagrams and have seen your excel sheet writeups with parts and links. Can you provide an excel sheet for the parts shown in that diagram and then I will down grade the part numbers for the 1 keggle setup I currently have and then will eventually double the parts once I'm ready to go AG.

Click to expand...

Just retrieve this Brewparts_Order.xls and save it on your system. You can change the QTY and the X column for the specific items that you want to secure. The sheet will automatically update the totals for you.

When you click on the URL column items, the particular part in displayed.

Hope this helps you.

Just saw this thread and had to pipe in. The NEC code is for every installed electrical piece of equipment and wiring which includes homeowner installations. Also article 422.10(A) states that the wiring for a continuously loaded appliance without a motor needs to be rated at 125% of the marked rating of that appliance. This means that you do have to obey the 80% load rule and cannot exceed 9600 watts of draw on a 50 amp circuit. As for using your existing 50 amp gfi breaker go for it. Run the conductors to a 60 amp (standard size) panel with 4 breaker openings and then install 2 double pole 30 amp breakers and run number 10 copper wire to 2 30 amp receptacles and you will be able to plug in 2 4500 watt elements at the same time.

On another note unless a breaker said it is switch rated on the side then it will wear out prematurely if you use it as a switch. Most gfi breakers are not rated this way as it causes increased wear on an expensive part. However most 30 amp breakers are commonly used in commercial lighting applications and already have this rating. Good luck with your project I hope this helps.

Thanks P-J in your diagram switches 1&2 will these work http://www.auberins.com/index.php?main_page=product_info&cPath=7&products_id=223&zenid=1a375e5758ee2edb7eedca59c3dde29d

sgoncalves said:

Thanks P-J in your diagram switches 1&2 will these work http://www.auberins.com/index.php?main_page=product_info&cPath=7&products_id=223&zenid=1a375e5758ee2edb7eedca59c3dde29d

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Those switches are rated for 10A max and are not capable of handling the current to the elements. You could use them if you set them up to control contactors that would then switch the element power.

yjfun said:

Just saw this thread and had to pipe in. The NEC code is for every installed electrical piece of equipment and wiring which includes homeowner installations. Also article 422.10(A) states that the wiring for a continuously loaded appliance without a motor needs to be rated at 125% of the marked rating of that appliance. This means that you do have to obey the 80% load rule and cannot exceed 9600 watts of draw on a 50 amp circuit.

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Grey area, but I'm leaning toward non-continuous load so 100% max is OK.

Continous Load. A load where the maximum current is expected to continue for 3 hours or more.

If you have 5500 watts x 2, it's likely that both will only be energized at 100% duty for a very short time. Once you reach a boil, you'll be PWMing at 50 or 60% on at least one of them.

I think it's a no brainer but you may want to go 5500 HLT and 4500 BK to leave room for pumps. The HLT is going to have a higher temp rise to deal with.

I would normally agree with you on the 3 hours or more for a continuous load but we are essentially building water heaters here and they are an exception to that code article. Article 422.13 states that "A fixed storage-type water heater that has a capacity of 120 gal or less shall be considered a continuous load." I realize that most brew systems are portable and this is still an area open for interpretation but there is a reason that these appliances are calculated in this way. I think in our application that running a 5500 watt and 4500 watt element on the same 50 amp circuit will probably not cause nuisance tripping due to heat buildup (or any other problems) but I felt the legality of such an installation should at least be brought up if something happened and an insurance company had to get involved.

I'd be curious how the electrical inspectors would weigh in on it. While describing this type of system, I'd certainly start by saying "well you know how an electric water heater works right?" but from an actual real world perspective, they are not being controlled with a simple on/off controller and it's not a single 11KW element. This system is also not being left to its own to run whenever the heat is called for 24/7. The reason a water heater would be considered constant use is that we have no way of knowing how much water will be consumed. As long as a certain threshold of use is reached, that element may be on for hours straight.

I'd be curious how many electric brew system builders have actually permitted and got an inspection on their system. I pulled the permit for doing the 200a service upgrade and the 50 spa panel. I just told the inspector that I wanted the outlet for a future option of running a welder. However, I have no plans of having an inspection done on my brew system.

It was just something to consider when building an electric system. The only difference I could see was that we monitor it when it's operating. Other than that it works in exactly the same way albeit with some simpler parts,(bi-metal thermostat and relay controlling two elements vs. pid and ssr controlling one or two elements), but otherwise it's the same stuff. I thank you for making me get out my code book and dig through it for the information. It seems like I don't do that enough any more and am starting to get a little rusty with my knowledge. Hopefully this will allow other builders to make the right choices when they build their own systems.

Getting a permit and inspection is only required for the building wiring. Once that building wiring is in place and terminates in a single drop outlet, all is good to go for the home brewer and the brew controller.

The idea of "nuisance tripping" just boggles my mind. Where does that come from? I'd like to see the factual information about this happenstance.

Regarding the original question, of whether or not a 50 Amp circuit, wired in 6 AWG is permissible to serve this 37.5 A load; you should have no problems, so long as nothing else is on this circuit. NEC 210.23 Permissible loads states: "An individual branch circuit shall be permitted to supply any load for which it is rated."

In a general purpose branch circuit supplying 2 or more outlets, no one cord and plug connected equipment may exceed 80% of the circuit rating, which I believe is where the original confusion came in?

Individual branch circuits are those which only supply ONE piece of utilization equipment. It can be either fastened in place or end in a single receptacle, such as one of these guys: (though a different design for 50A)





Now as to the topic of derating for continuous use, yjfun makes a very good point with article 422.13, and I think this might come down the the particular AHJ's interpretation of the code. In a basic way, it really is just a water heater by definition, but bobby_m explains the difference pretty well. I may just ask my inspector tomorrow to see what he would say in this situation.

P-J said:

Getting a permit and inspection is only required for the building wiring. Once that building wiring is in place and terminates in a single drop outlet, all is good to go for the home brewer and the brew controller.

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Good point, the building code is only for standard wiring and panels; the building inspector doesn't really see what you connect up to it. Anyone going to go through the trouble of getting their panels UL listed?

I had an master electrician and plumber over and showed him my dual element 120v BK, and asked for his frank assessment on my safety.

As Bobby mentioned, I started out with 'well, you start with a water heater and just replace the tank with a beer keg'

He gave me a gold star for using GFCI outlets, and for adding a grounding lug at the keg skirt. I explained the design concepts around using JB Weld to pot the elements and while he had concerns over the longevity of this due to heat--he agreed that this was about as safe and water proof as any strain relief. He did not like the idea of an outlet on the outside of the kettle at all. This is the same guy that told me he would NEVER come over for brew day if I built heatsticks. He warned me about using electrical cords in wet areas and strongly suggested that I use some squeeze clamps or guides to keep the wires off the counters and floors when brewing.

That said, he still gave me a 20% chance of electrocuting myself. ;-)

Hey, those are pretty good odds since the chance of 3rd degree burns is probably 22% on any given brew day.

Nuisance tripping is generally caused by heat build up due to a high load on a breaker. A standard 20 amp breaker is designed to run forever with 18 or less amps of draw on it (80%) but it will run for a while with 19.9 amps of load before the heat build up causes it to trip. This is called nuisance tripping when the breaker won't hold the load but isn't technically overloaded or shorting out. Some manufacturers are more prone to this problem than others.

Could somebody explain to me the way the emergency off switch works in the diagram by P-J? if it is being fed 120 VAC, and the switch is closed, wouldnt that cause (120/2000)A to be drawn through those resistors to ground? .06A is what i get which would not blow the fuse but would cause 7.2 watts to dissapate across the two 1kohm, 1 watt resistors. Wouldnt this overheat those two resistors?

Or is it a non-issue becasue the current will only run through that line momentarily until the breaker trips?

P-J said:

I'd like to see the factual information about this happenstance.

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So would I, P-J.