Consecutive batches on 30A?

[duanestorey]

Hi guys,

I'm sort of new here, but have been lurking a long time. I'm in the process of creating a 30A/5500W brewing system with 20G Megapots.

I love all the detail on the Electric Brewery website, and am currently waiting for parts to make my own control panel. One downside to the 30A system is that you can really only do one brew at once they way they have it designed. Their 50A system has it so you can run the HLT/Kettle at the same time, but it's not that easy to use 50A in an apartment (I rent, so I can't make any real modifications).

It sounds like most people heat up the brew kettle using the manual mode at a 100% duty cycle, then dial it back to 75% or so on a 5500W element to keep it boiling. At that point there is basically spare power that could be used to get the HLT going again for another batch. So I was thinking about adding some functionality to the control panel to allow for both heaters to be turned on at the same time, one at a 75% duty cycle and the other at a 25% in manual mode. Not sure how I would make this safe, other than a 30A fuse to make sure the wire never drew more (which basically means the user can't screw this up).

On a 5500W element that's almost 1400W that can be heating the water. Based on a calculator that's enough to get 10G of water back to strike temperature in about 90 mins, which is around the duration of the boil. So I'd be able to at least start a second brew while the kettle was boiling.

Any thoughts about this?

Thanks.

 

[bemerritt]

Not sure it will work. Could be wrong, but I believe the bk would be drawing full power 75 percent of the time. There is no way (that I can think of) to have hlt be firing during the 25 percent of the time that the bk isn't.

 

[IslandLizard]

Not sure it will work. Could be wrong, but I believe the bk would be drawing full power 75 percent of the time. There is no way (that I can think of) to have hlt be firing during the 25 percent of the time that the bk isn't.

Well put!

 

[wilserbrewer]

With an insulated mash tun, you could likely heat enough water during the 1st mash to let the 2nd batch mash while boiling the first batch.

Not sophisticated, but will fill the fermenters.

Or possibly reduce the 5500w element to two smaller elements, say a 4500 in the BK and and a 2000 in the HLT?

 

[duanestorey]

Not sure it will work. Could be wrong, but I believe the bk would be drawing full power 75 percent of the time. There is no way (that I can think of) to have hlt be firing during the 25 percent of the time that the bk isn't.

Ahh yes, thanks. That makes sense. I guess in theory you could use a transformer in this scenario and tap off two other voltages from the 240, i.e. 60V and 180V and use those. But may be more trouble than it's worth.

 

[Spellman]

I too am looking into building a 50a so that I can have the option of doing back to back. Don't know how much I'll actually be doing that, and I am finding out there is a premium in the cost of heavy enough cable and such. One thing I have recently considered is how much time it will actually save. I am wondering if you can just get the second batch up to temp while you are cleaning the bk from the first batch/getting yeast pitched/putting full fermenters away. Unless you have someone to help, it might just be just as easy to fill the hlt and start it up when you kill the boil from the first one. Maybe someone else can chime in with their experience in the matter.

 

[alien]

It can certainly be done. With a SSR governing each element, have a PWM operating on +/- 5V so that when one SSR is on, the other is off.

 

[MercMan]

Hi guys,

I'm sort of new here, but have been lurking a long time. I'm in the process of creating a 30A/5500W brewing system with 20G Megapots.

I love all the detail on the Electric Brewery website, and am currently waiting for parts to make my own control panel. One downside to the 30A system is that you can really only do one brew at once they way they have it designed. Their 50A system has it so you can run the HLT/Kettle at the same time, but it's not that easy to use 50A in an apartment (I rent, so I can't make any real modifications).

It sounds like most people heat up the brew kettle using the manual mode at a 100% duty cycle, then dial it back to 75% or so on a 5500W element to keep it boiling. At that point there is basically spare power that could be used to get the HLT going again for another batch. So I was thinking about adding some functionality to the control panel to allow for both heaters to be turned on at the same time, one at a 75% duty cycle and the other at a 25% in manual mode. Not sure how I would make this safe, other than a 30A fuse to make sure the wire never drew more (which basically means the user can't screw this up).

On a 5500W element that's almost 1400W that can be heating the water. Based on a calculator that's enough to get 10G of water back to strike temperature in about 90 mins, which is around the duration of the boil. So I'd be able to at least start a second brew while the kettle was boiling.

Any thoughts about this?

Thanks.

I think these guys do something like what you want with their controller, but I've not tried one.
http://goo.gl/dwrhD0

 

[jeffmeh]

It can certainly be done. With a SSR governing each element, have a PWM operating on +/- 5V so that when one SSR is on, the other is off.

Interesting. Wouldn't that make it pretty challenging for the HLT PID to tightly manage temperature, given that the PWM at times will be preventing the HLT element from firing when the PID "thinks" it is? I wonder how that would work in practice.

 

[alien]

Jeff, I have not fully thought it through but I think it would probably screw up the PID settings. You might have to set the HLT to manual at least until it was up to temp.

There has been some discussion of this sort of thing in relation to roll-your-own PID controllers (Arduino etc) but I think it should be possible to hack something for more conventional boxes that at least does part of want the OP wants.

Perhaps simplest is just a DPDT relay that flip-flops between sending 5V to the HLT SSR and 5V to the BK SSR, governed by the boil control?

 

[biertourist]

The easiest option is to just heat your 2nd batch's strike water while mashing as someone else said. I'm in the exact same situation as you right now. (Well I was until 4 weeks ago anyway; now I've got 50amps in the garage but a control panel still only built for 30 amps so pretty much the same situation.)

-Just put a switch into your control panel so you can switch from HLT to Kettle without unplugging cables and its' really a pretty easy workflow.

Adam

 

[WissaBrewGuy]

Couldn't you just have 30A going to both elements simultaneously but have the power go through a crossfade type switch so you could "pan" the current around the system? This would prevent tripping a breaker and you wouldn't risk a blown fuse. An electrical idea from a mechanical engineer... I know... scary...

 

[processhead]

It doesn't matter whether you do it with switches, transfer relays or just unplugging one kettle and plugging in another.

You are still sharing a limited power source between two loads and can't energize them both at the same time.

There's no free lunch with power distribution.

 

[MercMan]

It doesn't matter whether you do it with switches, transfer relays or just unplugging one kettle and plugging in another.

You are still sharing a limited power source between two loads and can't energize them both at the same time.

There's no free lunch with power distribution.

Why won't some sort of circuit that switches between 2 elements work?

 

[kenh]

When I'm bringing my batch up to full boil I want all available power going to that element. But once I'm at full boil I turn my PWM controller down & I'm at less than half power. Why can't the other half go to heating the initial strike water for the next batch?

These guys claim to do it with mash & sparge water, so I know it can be done with boil and initial strike water.
http://goo.gl/dwrhD0

Another though I had after going through this post a couple of times is my 5500 watt element only draws 22.9 amps but I'm running on a 30 amp circuit. This leaves 7 amps or 1700 watts available. Maybe part of the answer is to add a manually switched in 240V 1500 watt boost element to my sparge water tank? Does anyone know how many degrees a 1500 watt element will raise 8 - 12 gallons of water in 1.5 hours?

 

[chickens4life]

I don't think you actually need to heat both at the same time, as was said before. When hearing our sparge water for batch 1 heat enough for your strike water for batch 2 as well. Then you won't need that element again till it is time to heat sparge water for batch 2. Then at the end of boil 1 you go back to heating hlt and then you will have sparge water ready by the time your bk is available to start lauteting the second batch.

 

[kenh]

I don't think you actually need to heat both at the same time, as was said before. When hearing our sparge water for batch 1 heat enough for your strike water for batch 2 as well. Then you won't need that element again till it is time to heat sparge water for batch 2. Then at the end of boil 1 you go back to heating hlt and then you will have sparge water ready by the time your bk is available to start lauteting the second batch.

If I get that efficient I'll have to start a beer IV just to keep up with production! I was only interested in running two 10 gallon batches, one after the other. I figure I have the basement ready to do one & might as well do two.

So, if I follow you right I:

1. Heat my first strike water
2. Start my first mash
3. Heat my first sparge water & second strike water together
4. Sparge my first mash into my brew pot
5. Start my first boil
6. Start my second mash
7. Heat my second sparge water
8. Transfer my first batch to the fermenter
9. Sparge my second mash into my brew pot
5. Start my second boil

I still see a problem - My mash is 1 hour and my boil is 1.5 hours. I will have to heat my second sparge water the same time I am doing my first boil. Did I miss something?

 

[SookeBrewing]

Hey Duane - I know you from the Internet! Also, I think we may have met once at some blogging thing with Rebecca?

Anyway, welcome to the wonderful world of electric brewing! I completed my Electric Brewery build in late summer and have been enjoying it ever since. If you want hints on sourcing parts, etc. or have any questions, feel free to get in touch. If you look at my post history you will find my build thread too.

Have fun!

-Tim

 

[processhead]

When I'm bringing my batch up to full boil I want all available power going to that element. But once I'm at full boil I turn my PWM controller down & I'm at less than half power. Why can't the other half go to heating the initial strike water for the next batch?

These guys claim to do it with mash & sparge water, so I know it can be done with boil and initial strike water.
http://goo.gl/dwrhD0

Another though I had after going through this post a couple of times is my 5500 watt element only draws 22.9 amps but I'm running on a 30 amp circuit. This leaves 7 amps or 1700 watts available. Maybe part of the answer is to add a manually switched in 240V 1500 watt boost element to my sparge water tank? Does anyone know how many degrees a 1500 watt element will raise 8 - 12 gallons of water in 1.5 hours?

To do this you would need to be able to manipulate the duty cycle of the pulse signal going to kettle 1's element so that during the off-time interval kettle 2's element is being switched on.

People have probably programmed controllers to do this or even used hardware on circuit board that inverts the duty cycle.

The timing would be critical since anytime both elements are switched on at the same time, the supply circuit would be overloaded.

Others have repeated this before, but just to be clear, most power control is done with on-off controls that deliver full power to the element while switched on, just not continuously.

With shared power, to multiple elements, the total power to both elements could never exceed 100% full load power going to a single element. It would always be 10-90, 50-50, 75-25 or whatever.

 

[chickens4life]

If I get that efficient I'll have to start a beer IV just to keep up with production! I was only interested in running two 10 gallon batches, one after the other. I figure I have the basement ready to do one & might as well do two.

So, if I follow you right I:

1. Heat my first strike water
2. Start my first mash
3. Heat my first sparge water & second strike water together
4. Sparge my first mash into my brew pot
5. Start my first boil
6. Start my second mash
7. Heat my second sparge water
8. Transfer my first batch to the fermenter
9. Sparge my second mash into my brew pot
5. Start my second boil

I still see a problem - My mash is 1 hour and my boil is 1.5 hours. I will have to heat my second sparge water the same time I am doing my first boil. Did I miss something?

That is the work flow is was picturing. also shouldn't be a problem for to have a longer boil, just make sure you have some sort of insulation on your mash tun and you can leave the strike water in there for the second batch for a bit, it will probably actually have to cool down a bit from sparge temps any way. that way you can time it so that your second mash ends a little after your first boil (so you have some time to heat sparge water transfer/cool first batch and rinse out the BK before you start the lauter).

when I upgrade next it will be to a 30A rig with that sort of work flow for double days.

another option is to run 4500W in the boil kettle and 1500 or 2000 in the HLT. then use the BK to heat the initial strike water, as well as the combined sparge and strike water. then just transfer that water to the HLT right before lautering, the only thing you would really need the element in the HLT for would be to heat sparge water for the second batch during the first boil (and if you where hopping to use the hlt as a herms vessel), and you would not be in a hurry to get that up to temp.

just throwing some ideas around.

-chickens

 

[Bobby_M]

Small heat exchange coil in the boil kettle? Circulate water from your HLT through it and have a controller shut the pump off when it hits your desired temp. The boil element would have to run at 100% during that time, but I think it could be done, maybe.

 

[kenh]

Small heat exchange coil in the boil kettle? Circulate water from your HLT through it and have a controller shut the pump off when it hits your desired temp. The boil element would have to run at 100% during that time, but I think it could be done, maybe.

It seems to me that a small coil in the boil kettle + a pump would be more expensive than coming up with a circuit to turn a second element on when the first is off.

I'm thinking that maybe I just need a relay with contacts that are closed when it's off. The relay coil would be wired across the brew pot element so it's on when the brew pot element is on. The contacts would be wired so that the element is turned off when the coil is on.

Am I missing something here?

 

[OMJ]

This guy runs 2 5500watt elements off a 30a circuit. Pretty awesome.

https://www.youtube.com/watch?v=eHrI0EKLxtk&feature=youtube_gdata_player

 

[mrwizard0]

What I you built an option to run the elements a 110 as well as 220. Yes I understand that you will only get 1/4 of the power but here's my thought. Heat the mash/strike water for both batches on the first run. Then when you transfer to the bk you run it at 220 to get the boil started. When the boil is started, switch to 110 to maintain the temp in the hlt as well as hold the boil. I don know if that would be enough to maintain the boil of not, but it's a thought. Or you could have 2 elements in the bk, one higher and one lower and swap between them

 

[Bobby_M]

It seems to me that a small coil in the boil kettle + a pump would be more expensive than coming up with a circuit to turn a second element on when the first is off.

I'm thinking that maybe I just need a relay with contacts that are closed when it's off. The relay coil would be wired across the brew pot element so it's on when the brew pot element is on. The contacts would be wired so that the element is turned off when the coil is on.

Am I missing something here?

I guess I was assuming one would already have a pump.

After a little more thought, using an interlock relay is practical. If one were using a PWM driver circuit with normal SSRs, the pulse signal could be used to energize a small relay that has the other SSR's pulse signal running through the NC contacts.

The VSSR method is a little different in that the SSR is not being pulsed externally. In that case, you'd have to have the 240v output of one VSSR energizing a relay with a 240v coil. In that case, the second SSR would be energized with a DC pulse running through that relay's NC contacts.

 

[kenh]

I guess I was assuming one would already have a pump.

After a little more thought, using an interlock relay is practical. If one were using a PWM driver circuit with normal SSRs, the pulse signal could be used to energize a small relay that has the other SSR's pulse signal running through the NC contacts.

The VSSR method is a little different in that the SSR is not being pulsed externally. In that case, you'd have to have the 240v output of one VSSR energizing a relay with a 240v coil. In that case, the second SSR would be energized with a DC pulse running through that relay's NC contacts.

I have a CHUGGER pump but it's setup to circulate through my RIMS tube. I am going to look at the relay idea.