Electric brewery plans - need help - Page 2 - Home Brew Forums

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06-25-2010, 02:16 AM   #11
Tiber_Brew

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Apr 2010
Upper Peninsula, Michigan
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Quote:
 Originally Posted by mattmauriello wanna know my thoughts? yes? ok... for the illuminated switches, must are NOT 120V, especially if they're LED. check the datasheet. read this thread for ideas on how to get the voltages right and not blow anything up.
I've been looking at illuminated switches where the indicator takes full voltage, so no worry there. Thanks for the concern though! I'm glad there are many good thinkers on HBT who pay attention to those details!

Quote:
 now, looking at the drawing, that is set up to get 2 seperate 240V lines fed to the control box, so you can run both elements at teh same time,
Not quite. It's a 240VAC input, which is basically two 120VAC legs, a neutral, and a ground. Some bus bars or terminal blocks will distribute the power from there, so long as I don't run too many circuits in parallel and trip the breakers.

Quote:
 but notice the breakers are 20 amps. you need 30 amps for your 5500W elements.
By my calculations: 5500/2= 2750W
2750W/120V=22.9Amps

Perhaps I do need 30 amp breakers?

Quote:
 Originally Posted by zerin27 This is a great thinking.There are different types of switching circuit in market.The conventional idea can be thermistor.or different kind of IC controlled logic circuit can be implemented.Because uyou are having a huge load so You have to keep this away from your house firepits and other risky elements.
I'm sorry...what?

Quote:
 Originally Posted by AiredAle This diagram is a good starting point. I would echo the 30 A circuit breaker suggestion, and if you don't use a gfci in the spa box, then go with 30 A gfci circ brkrs. Also I would suggest 40 amp SSRs instead of 25 A as the diagram suggests, since your 4500 W elements will draw 19 to 20.5 amps at 240 v 0r 220 v depending on your house voltage. This is pretty close to their max, and they will get hot. In either case, you will need good heat sinks for the SSRs.
Perhaps the 30A breakers are better. I'm actually using 5500W elements instead of the 4500W from the diagram, so the higher current handling breakers are even more deserving, eh?

Quote:
 Finally, on my panel I have a master switch that controls all the 120 volt devices, and when this is turned off, nothing can turn on. Another finally, is you should consider fuses on the hot line feeding each of your 120 v devices, they are cheaper than replacing a component that you have let the smoke out of.
Are you suggesting replace the breakers with fuses? Or add fuses in addition to the breakers?

Quote:
 Originally Posted by Walker His elements are 5500W, not 4500W. The diagram is not his system, just a diagram for a system that is very close to what he wants.
Right-o

Quote:
 I would still go with 40A SSR's, even if you only need 25A. The price difference is basically nothing. You can find 40A SSR's with heatsinks on ebay for \$14 (free shipping). About the switches. 120V illuminated switches are not hard to find. I shopped for most of my small electronics as mouser.com and found illuminated switches that run off 120VAC. They were about \$1 per switch.
Found very similar switches. Thanks Walker.

OK, so here's a bit of an update:

I'm using two double pole SSRs, and moving the element power switches from after the SSRs to before the SSRs (between PID and SSR). I'm switching both legs of the elements with the DPSSR instead of one leg with standard SSRs, and I can turn both legs completely off with one illuminated switch that sees about 12VDC. I also am going to use heat sinks for both the DPSSRs, since they're 25amps. If I have problems with those, I'll get the 40amp double pole SSRs. (The 25A double pole SSRs were free, BTW.)

I also think I'm going with the Auber PID SYL-2352 instead of the universal. Perhaps the universal will still work for the BK, since I don't need real precise algorithms to boil sugar water.

Here is a revised, but not entirely up to date diagram I modified today

Keep in mind I'm moving the switches 1&2 behind the SSRs so I can use low voltage illuminated ones and both legs will be shut off due to the double pole SSRs.

EDIT: switches 1 & 2 are going to be SPST on the positive lead to the SSR since it's DC. (On both SSRs) Thought I'd clear that up too.

I might also use bus bars instead of terminal blocks, but that's minor.

I appreciate all the feedback and questions! Keep 'em coming! Any feedback is welcome!
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On tap:
1. none 2. Michigan IPL 3. Helles 4. Oatmeal Stout 5.[Nitro] Oat Blonde
Conicals:
FV1: American Pale FV2: Brown Porter
Carboys:
1. Brett Ale 2. none 3. none 4. none 5. none
Bottled:
Kegged & conditioning:
Rye Barrel aged DIPA, Helles, Kentucky Common, Oatmeal Stout

06-25-2010, 02:33 AM   #12
Walker
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I bought 25A breakers for my ststem, and then started worrying about my 5500W element causing nuisance trips of the breaker because I didn't give them enough margin. Fortunately, I have not had the breakers trip at all for me, and I've brewed twice with it, am cooking babyback ribs in it now (check out "sous vide" cooking style) and have played with the thing a BUNCH making sure it all worked. Not one trip of a breaker.

SO... I'd go with 30A breakers, to avoid the concern of tripping when there really is no problem. Keep in mind that this might mean you'll have to use fatter wires to deal with inside the control box. (Your wire has to handle whatever current the breaker will allow through.)

He's not suggesting taking out your breakers and using fuses instead. He's talking about using little tiny fuses to protect things like the PID. Those things don't need much current to operate, so you can protect them with very small fuses that will blow if something goes wrong. The diagram has the 120V stuff on a 15A breaker. This is pretty much like an outlet in your house. But, 15A is WAY MORE than enough to kill a PID, so you protect it with a small (1A?) fuse so that the PID is properly protected.

I actually don't have any fuses in my system at this point, but it's something I want to add.
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06-25-2010, 12:33 PM   #13
Tiber_Brew

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Upper Peninsula, Michigan
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Thanks for the good info, Walker. I'm def going to look into 30A breakers now. Perhaps 1A fuses are in order too...

I'll run this info by the electrical engineers at work, and see what they think of this diagram and your suggestions. (I'm just an electronically retarded mechanical engineer.)

Cheers guys!
TibernotmuchlongernowBrew
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On tap:
1. none 2. Michigan IPL 3. Helles 4. Oatmeal Stout 5.[Nitro] Oat Blonde
Conicals:
FV1: American Pale FV2: Brown Porter
Carboys:
1. Brett Ale 2. none 3. none 4. none 5. none
Bottled:
Kegged & conditioning:
Rye Barrel aged DIPA, Helles, Kentucky Common, Oatmeal Stout

06-25-2010, 12:35 PM   #14
P-J
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Mar 2010
Charlotte, NC
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Quote:
 Originally Posted by Tiber_Brew ... That diagram doesn't fit my design quite exactly, but, damn, it is it ever close. TiberwillhappilypayitforwardBrew
Just saw this post (have not read the balance of the thread yet).

What do you need that is different. The diagram you posted was planned and drawn by me. I'd be more than willing to make any changes that you need for your setup.

Let me know.

06-25-2010, 12:54 PM   #15
P-J
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Charlotte, NC
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Tiber_Brew - we really need to talk. I want you to have it right and safe. There is a bit of mis-information posted in this thread.

Please tell me what your overall objective and design plan calls for. I can help.

06-25-2010, 01:10 PM   #16
SweetSounds

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Des Moines, Iowa
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I would leave the DPST switches between the SSR's and the elements. It's safer that way, and if the SSRs fail closed, you can still kill the power to the elements.
A couple other things I'd change (Or at least recommend)
Lose the home type of breakers. They have to be installed in a special panel, and are not really available in smaller amperages.

Install a DIN rail in your enclosure, and use DIN mount breakers like these:
The wiring doesn't change, but it'll be safer just because they mount securely, and the connections are behind plastic to keep your fingers out.

They will also enable you to put the appropriate breakers on your pumps. 15 amps is way too much for a 1.4 amp motor. Use 2 amp "D curve" single pole DIN breakers.
(Think of "B Curve" as fast blow for resistive loads like elements, and "D Curve" as slow blow for inductive loads like motors)

The other thing I'd do is install an SSR on both legs of the elements (So a total of 4 SSRs). It's personal preference for me, and many here have used just one. But if you manage to touch the wire after a single SSR, even if it's off, you risk completing the circuit to the un-switched side. Ouch.

Oh, And use terminal strips. Buss bars are not insulated in any way. They can short to you, or they can short to the enclosure. Neither is a good place to be. At least terminal strips are insulated from whatever you are mounting them to.
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Quote:
 Originally Posted by Ecnerwal What does the primary pressure gauge on the tank tell us? That's right, the temperature. Put it on a scale if you want to know how much is in it...
Put some duct tape over the gauge - Or better yet - Replace the high pressure gauge with a plug - High pressure gauges are useless!

06-25-2010, 02:37 PM   #17
mattmauriello
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Apr 2010
Silver Spring MD
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Quote:
 Not quite. It's a 240VAC input, which is basically two 120VAC legs, a neutral, and a ground. Some bus bars or terminal blocks will distribute the power from there, so long as I don't run too many circuits in parallel and trip the breakers.
embarrassed i missed that one, but you're definitely right. looking good to me. I second the additional SSRs so you can switch both legs of th 240, and really think a selector switch between the pid and SSR is good choice, just so you never accidentally fire both up at the same time and pop your breakers.

06-25-2010, 03:04 PM   #18
Walker
I use secondaries. :p

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Quote:
 Originally Posted by P-J Ok.. Just finished reading the thread. Tiber_Brew - we really need to talk. I want you to have it right and safe. There is a bit of mis-information posted in this thread. Please tell me what your overall objective and design plan calls for. I can help.
Please publicly point out whatever misinformation is in here for the betterment of the community and to correct anyone who might be doing something unsafe in their own system.
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06-25-2010, 03:14 PM   #19
Walker
I use secondaries. :p

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Quote:
 Originally Posted by Tiber_Brew By my calculations: 5500/2= 2750W 2750W/120V=22.9Amps
I just noticed this. I don't where you were going with the "5500/2=2750W" and then "2750W/120V" calculations above.

To figure amp draw, you just divide the power by the voltage.

5500W/240V = 22.9A

You accidentally arrived at the right answer because you first divided by 2 and then divided 120V, which is mathematically the same as dividing by 240V, but something is wrong with the thought process you were using there.
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06-25-2010, 03:26 PM   #20
Walker
I use secondaries. :p

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Quote:
 Originally Posted by Tiber_Brew I'm using two double pole SSRs, and moving the element power switches from after the SSRs to before the SSRs (between PID and SSR). I'm switching both legs of the elements with the DPSSR instead of one leg with standard SSRs, and I can turn both legs completely off with one illuminated switch that sees about 12VDC. EDIT: switches 1 & 2 are going to be SPST on the positive lead to the SSR since it's DC. (On both SSRs) Thought I'd clear that up too.
From what I have read, SSR's can fail in the "ON" mode. If that happens, then the switches you put in to kill the SSR control signal from the PID won't accomplish anything and the lines going to the heater element will be live.

You are better off actually killing the 240V hot lines rather than the SSR control signal from the PID.

And... if you are really wanting to keep it as safe as possible, I personally wouldn't use a big DPST toggle switch to directly control the 240V lines. There will be a lot of current flowing through those switches . I thought about using big burly toggle switches like that in my system but then realized that there would be 23A flowing through that switch and I would be directly touching it... possibly with wet hands.

not only that, but my switches are on a hinged door. If I would have used big toggle switches capable of handling the 240V/23A, I would have had to run very heavy gauge wiring to that switch on the panel. Opening and closing the door would have been more difficult.

So... I opted to use a 2-pole contactor to pass the 240V through to the elements, and that thing (along with the large wires) is down in the belly of my control box. The contactor is triggered with a 120V signal (and draws only 0.5A). So, I have a 120V illuminated switch on the door with a small wire that feeds down into the contactor to enable it.

The contactors take up a lot of space, but I really didn't want to touch a big 240V/23A toggle switch. (The contactor was the same price as the Big Switch, too.)
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