3 Phase power questions

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cruelkix

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So I'm opening a small brewery: Brewery Build thread

I just got off the phone with my electrical engineer and he said that the building has 3 phase 240v (rare I know) and that I can provide enough power for my 6 x 5500 watt heating elements with 2 x 50 amp plugs on 3 phase?

3 phase has always confused me. Do I have to change anything I am doing? He is going to provide everything to the plugs. From the plugs I was going to come into distribution blocks in my panel and then go to the SSRs and such.

So the real question here. Do I wire anything differently than I would for single phase other than accounting for the differences in amp draw?

Thanks!
 
Depending on if you have three wire or four wire three phase... shouldn't be hard to convert to single phase

convert-electric-single-phase-electric-800x800.jpg
 
Sorry, I don't mean to offend Huntb, but that is entirely incorrect. You are showing single phase wiring, and it's incorrectly labeled.

Cruelkix, I've built three phase control panels before, and it's not that hard to do. A fully variable controller with individual element selectivity and control and PID integration is as complicated as I've built yet, but it works. One thing you will need to do is run three elements per 3ph circuit. You state you want to run 6 5.5kw elements, where would each element be?

If you are interested in what a 3 phase panel could look like, here's one I built not long ago.

small pic of wiring.jpg


no logo.JPG
 
Sorry, I don't mean to offend Huntb, but that is entirely incorrect. You are showing single phase wiring, and it's incorrectly labeled.

Cruelkix, I've built three phase control panels before, and it's not that hard to do. A fully variable controller with individual element selectivity and control and PID integration is as complicated as I've built yet, but it works. One thing you will need to do is run three elements per 3ph circuit. You state you want to run 6 5.5kw elements, where would each element be?

If you are interested in what a 3 phase panel could look like, here's one I built not long ago.

Thanks. I would have 3 elements in my HLT and 3 elements in my BK. So if I can hook 3 elements up per circuit that works perfectly. I can just put each kettle on a circuit right?

I guess at that point I'm just wondering how 50 amps is going to run 3 elements?
 
the formula is watts = amps x volts

What voltage are your 5500w elements?

If you have a 240v 50A service then you have 12000 Watts of power total on the service. The problem may be that your voltage won't match your equipment and you may end up replacing some transformers.

In general you are going to run into 2 types of devices - 120v and 208v. The 120v is a normal household device - like a lamp. A 208v device uses two legs (phases) of 120v and combines them to get a total of 208. If this is new to you then you really need to get an electrician involved.
 
the formula is watts = amps x volts

What voltage are your 5500w elements?

If you have a 240v 50A service then you have 12000 Watts of power total on the service. The problem may be that your voltage won't match your equipment and you may end up replacing some transformers.

In general you are going to run into 2 types of devices - 120v and 208v. The 120v is a normal household device - like a lamp. A 208v device uses two legs (phases) of 120v and combines them to get a total of 208. If this is new to you then you really need to get an electrician involved.

Yeah that all works on single phase stuff. I'm aware of all that. I'm wondering if 3 phase is going to change that up.

Like the original post says, the building I'm going into has 3 phase 240v, and I have an electrical engineer working on this project. Did you read the first post at all?

I have already built an electric brew rig that works just fine with 2 5500 watt heating elements. Whats new to me is 3 phase and what that changes.
 
Each leg will see a current draw that is equivalent to 1.73 of two elements. So, 2*5500/208=52.88amps / 1.73 = 31 amps per leg roughly.
 
Yeah that all works on single phase stuff. I'm aware of all that. I'm wondering if 3 phase is going to change that up.

Like the original post says, the building I'm going into has 3 phase 240v, and I have an electrical engineer working on this project. Did you read the first post at all?

I have already built an electric brew rig that works just fine with 2 5500 watt heating elements. Whats new to me is 3 phase and what that changes.

No insult intended - if my comment wasn't helpful please accept my apology.

If you're working with 208v heating elements you're already working on more than one phase. Each leg in a three phase system is normally 120 degrees out of phase with the others. This is the reason that 120v + 120v = 208v not 240v. If you combine two legs (phases) of power that are in phase with each other then 120 + 120 = 240.

three phase 240 is unlikely to give you the voltage you need if you're re-using equipment from your previous brew house that was located in your house. Standard home wiring in the US is two phase 120 - allowing you to sum phases in order to get 208 for electric stoves, HVAC, dryers etc.

What voltage are your heating elements looking for? My guess would be 120v or 208v - neither of which is going to come out of a three phase 240 panel.

Now, it's possible that your EE is referencing a three leg 120 system where all legs are in phase - but that seems unlikely.
 
No insult intended - if my comment wasn't helpful please accept my apology.

If you're working with 208v heating elements you're already working on more than one phase. Each leg in a three phase system is normally 120 degrees out of phase with the others. This is the reason that 120v + 120v = 208v not 240v. If you combine two legs (phases) of power that are in phase with each other then 120 + 120 = 240.

three phase 240 is unlikely to give you the voltage you need if you're re-using equipment from your previous brew house that was located in your house. Standard home wiring in the US is two phase 120 - allowing you to sum phases in order to get 208 for electric stoves, HVAC, dryers etc.

What voltage are your heating elements looking for? My guess would be 120v or 208v - neither of which is going to come out of a three phase 240 panel.

Now, it's possible that your EE is referencing a three leg 120 system where all legs are in phase - but that seems unlikely.

No offense taken. Sorry if I came off snippy.

The heating elements are 240v. So I think like swede is saying I'll be seeing 31 amps per leg.

edit: my house has a 240v panel in the garage. In the US most houses end up with 240v where as most commercial properties get 208v. Oddly enough the commercial building I am going into has 3 phase 240v. Which is not very common in the US thats for sure.
 
watts = amps x volts

so 5500 = ? x 240

= 22.92 amps per element.

yay, use for simple algebra!

now, how you calculate the total load is based on the configuration of the elements themselves - here's a little pdf I found talking about it:

http://www.ppe.com/11cat/0852.pdf

If you're wiring the elements in series or parallel as far as I understand you'll end up pulling the total of all of the elements in the set - so two elements will draw a bit more than 45 amps.

swede - am I wrong about that?
 
Each leg will see a current draw that is equivalent to 1.73 of two elements. So, 2*5500/208=52.88amps / 1.73 = 31 amps per leg roughly.

Ok, cool. So he is going to give me a 50 amp 3 phase plug and I will have to run a cord with all 3 legs (and a neutral I would guess) into my panel. From there each leg goes to 1 element a piece then?

Can I use a solid state relay to turn them on and off like I have done in the past?

Thanks for info on all this swede.
 
you're still thinking in single phase.

each leg will see 1.73 of the equivalent single phase load of two elements.

so, with 240v and 5500w elements the math is thus...

2*5500/240/1.73=27 amps per leg at 240, remember higher voltage means lower amperage draw...
 
watts = amps x volts

so 5500 = ? x 240

= 22.92 amps per element.

yay, use for simple algebra!

now, how you calculate the total load is based on the configuration of the elements themselves - here's a little pdf I found talking about it:

http://www.ppe.com/11cat/0852.pdf

If you're wiring the elements in series or parallel as far as I understand you'll end up pulling the total of all of the elements in the set - so two elements will draw a bit more than 45 amps.

swede - am I wrong about that?

That PDF is neat. I think I will be using either delta or star. I think that is where the confusion is coming from.
 
Ok, cool. So he is going to give me a 50 amp 3 phase plug and I will have to run a cord with all 3 legs (and a neutral I would guess) into my panel. From there each leg goes to 1 element a piece then?

Can I use a solid state relay to turn them on and off like I have done in the past?

Thanks for info on all this swede.

Use 40amp rated ssr's and you should be good. There's no need for a neutral in your panel if you arent planning on running any 120v stuff in there. You still need a ground though.

The ssrs will switch power to the elements, yes. Three ssrs, three lines in, three elements out. The wiring is pretty straighforward if you want to switch all three on and off at the same time, if you want individual control of each element it gets a bit more complicated.
 
right, the square root of 3... Is that right?

Sorry, it's been a while. I work with entertainment electrical systems all the time - but they're all 120/208 stuff.
 
Use 40amp rated ssr's and you should be good. There's no need for a neutral in your panel if you arent planning on running any 120v stuff in there. You still need a ground though.

The ssrs will switch power to the elements, yes. Three ssrs, three lines in, three elements out. The wiring is pretty straighforward if you want to switch all three on and off at the same time, if you want individual control of each element it gets a bit more complicated.

Nice. That works perfectly. I have all 6 40amp SSRs already, so I'm glad I can use those.
 
Use 40amp rated ssr's and you should be good. There's no need for a neutral in your panel if you arent planning on running any 120v stuff in there. You still need a ground though.

The ssrs will switch power to the elements, yes. Three ssrs, three lines in, three elements out. The wiring is pretty straighforward if you want to switch all three on and off at the same time, if you want individual control of each element it gets a bit more complicated.

Also, I don't think it is a big deal if I run them all at once or individually. Individually would let me do smaller batches, but that is about the only reason I can think of not running all 3 at once.
 
Also, I don't think it is a big deal if I run them all at once or individually. Individually would let me do smaller batches, but that is about the only reason I can think of not running all 3 at once.
Sounds like you need a wiring plan (diagram) with a little more info in it to help you sort it all out. With that said, I spent a few hours this evening drawing a diagram for you using 240V - 3 Phase Delta power that should fit your needs.

The RTD temp probe could be the Deluxe version of Liquid Tight RTD Sensor. It is well worth the extra $9 for it.

With the Auber Instrument PID SYL-2352, you have a manual mode that will allow you to dial the power down and control the boil rate. I also show a 3rd PID for the Mash Tun. This is for monorting the mash temperature only & only if that is something you want to do.
I hope this is of some help to you.

As always - Click on the image to see a full scale diagram printable on Tabloid paper (11" x 17")



Wishing you the best.

P-J
 
Sounds like you need a wiring plan (diagram) with a little more info in it to help you sort it all out. With that said, I spent a few hours this evening drawing a diagram for you using 240V - 3 Phase Delta power that should fit your needs.

The RTD temp probe could be the Deluxe version of Liquid Tight RTD Sensor. It is well worth the extra $9 for it.

With the Auber Instrument PID SYL-2352, you have a manual mode that will allow you to dial the power down and control the boil rate. I also show a 3rd PID for the Mash Tun. This is for monorting the mash temperature only & only if that is something you want to do.
I hope this is of some help to you.

As always - Click on the image to see a full scale diagram printable on Tabloid paper (11" x 17")



Wishing you the best.

P-J

You're so awesome. I've seen you put these together for other people and seriously, you just rock. Thanks so much for spending the time for me and all the other people you have helped.

If you are in the Denver area ever come to my brewery (High Gravity Brewing, Inc.) and you drink for free that night for all the help you given on this forum.

I'm opening in December I hope.

On a details side of things:

I only have one pump so that cleans up the bottom a bit and all of the ssr switching and temperature sensors run off of my Labjack that I use to run the system. Its all automated and nice and has a 7" touchscreen for turning on and off everything and setting temperatures and power percentages for maintaining boil and such. So all the PID stuff can dissappear as well and get replaced with the I/O device for the labjack.
 
cruelkix,

Please refresh you view of the diagram. I caught some errors on the wiring plan after I posted it and then fixed them. I called out the elements as 5000W units. It's fixed now. I see that you replied before I had a chance to complete the fix so I thought it would be best to advise you.

Hope this fits your needs.

P-J
 
Different arrangement, same dissipated power / heat.

So I can hook up the power to my 3 phase steam kettle and use single phase and it won't matter? I asked this question about a year ago. Heating elements don't care, motors do, right?
 
So I can hook up the power to my 3 phase steam kettle and use single phase and it won't matter? I asked this question about a year ago. Heating elements don't care, motors do, right?

Elements don't care at all, but you won't get as much heat as you want.
Are you sure it's 3-phase? How many leads? Can you measure the resistance between 2 of them?
 
Be careful messing around with 120/240v 3 phase. Its a common amatuer electrician mistake to accidently hook something up onto the "high leg" . essentially every third breaker is not to be used for single phase loads (line to neutral) as that leg carries 200+ volts on it. Line to line you will get a nominal voltage of 240v , On two of the legs you will get 120v to ground, but on the one of the three legs will have a much higher voltage to ground. If you accidently hook your pumps up to that leg (or anything else that normally runs on 120v), you will burn them up.


PJ- I think there are still a few mistakes in you drawing. Your 30a 3 phase breakers will not hold all three elements going at the same time. If it was a 3 phase two element rig you could get away with it set up as. Elemet one = line 1,2. element two= line 2,3. To balance the load. That way you only had a 5500 watt load on each leg. But with three elements you'd be running 16,500 watts / (1.73 x 240)= 40a on each leg of your 3 phases. If you're going to use three elements I would hook them up element one Line 1, 2. element two. line 2,3. element three line 1,3. This would balance the load between the three elements. And the ssr would need to be split up accordingly. the three elements would be fed. L1 R2, L2 R3, L3 R1. L= straight line power off the breaker and R= power ran thru the ssr.

Grandequeso
 
Be careful messing around with 120/240v 3 phase. Its a common amatuer electrician mistake to accidently hook something up onto the "high leg" . essentially every third breaker is not to be used for single phase loads (line to neutral) as that leg carries 200+ volts on it. Line to line you will get a nominal voltage of 240v , On two of the legs you will get 120v to ground, but on the one of the three legs will have a much higher voltage to ground. If you accidently hook your pumps up to that leg (or anything else that normally runs on 120v), you will burn them up.


PJ- I think there are still a few mistakes in you drawing. Your 30a 3 phase breakers will not hold all three elements going at the same time. If it was a 3 phase two element rig you could get away with it set up as. Elemet one = line 1,2. element two= line 2,3. To balance the load. That way you only had a 5500 watt load on each leg. But with three elements you'd be running 16,500 watts / (1.73 x 240)= 40a on each leg of your 3 phases. If you're going to use three elements I would hook them up element one Line 1, 2. element two. line 2,3. element three line 1,3. This would balance the load between the three elements. And the ssr would need to be split up accordingly. the three elements would be fed. L1 R2, L2 R3, L3 R1. L= straight line power off the breaker and R= power ran thru the ssr.

Grandequeso
You do not have a clue. But - in that case I'll just take it down. (I believe you are mistaken - however.) Good first post.! Saves me one hell of a lot of time going forward.!

You are all on your own now.

I'm Done...
 
We don't have to get all worried about a few stray volts. I apologize if my question caused an issue. What was the saying? "220, 221 whatever it takes."
Name the movie.
 
Winner Winner, Chicken Dinner! Nice! I thought I was the only guy that remembered that...
 
You do not have a clue. But - in that case I'll just take it down. (I believe you are mistaken - however.) Good first post.! Saves me one hell of a lot of time going forward.!

You are all on your own now.

I'm Done...

A little touchy are we? I didn't post to offend anyone. I'm a service electrician. I work with different nominal voltages in different environments everyday. I just chimed in to be of help, in a area I have more experience than most.

I gave you my math. Tell me where I'm wrong... I'm wrong all the time. I'm open to learn something new. That being said.

Configure it anyway you want. watts are watts. three 5,500 watt elements on one breaker is 16,500 watts and at @ 240volts 3phase it is way more than a 30 amp breaker can handle. Do a google search check for yourself.
 
A little touchy are we? I didn't post to offend anyone. I'm a service electrician. I work with different nominal voltages in different environments everyday. I just chimed in to be of help, in a area I have more experience than most.

I gave you my math. Tell me where I'm wrong... I'm wrong all the time. I'm open to learn something new. That being said.

Configure it anyway you want. watts are watts. three 5,500 watt elements on one breaker is 16,500 watts and at @ 240volts 3phase it is way more than a 30 amp breaker can handle. Do a google search check for yourself.

Don't worry about it - you did nothing wrong. PJ has done this exact thing before - gets mad and says he quits when he is questioned.
 
This might help you out, disregard the inaccuracy of the SSR's, you know what they do. This should help you set up a sys that will work individually as well. Each element has 2 pole circuit protection here, remove it if you don't want it.

The line load on each phase will calculated according to the appropriate formula, each element will draw 23a @ 5500w. You may want to increase the breaker capacity to a 32a instead of a 25a to stay under 80% if you wish. The 40a rated ssr's I recommended will be fine.

3phase.JPG
 
This might help you out, disregard the inaccuracy of the SSR's, you know what they do. This should help you set up a sys that will work individually as well. Each element has 2 pole circuit protection here, remove it if you don't want it.

The line load on each phase will calculated according to the appropriate formula, each element will draw 23a @ 5500w. You may want to increase the breaker capacity to a 32a instead of a 25a to stay under 80% if you wish. The 40a rated ssr's I recommended will be fine.

swede, you rock. That makes total sense. Thanks for your help on this!!
 
Swede the individual breakers at each element is a really clever idea. If you were to ever short circuit an element you would not have to stop your brew. just cut out that element and continue your brew.
 
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