3600w Single Vs 4800w Three Phase For Electric Kettle

[YZ250]

As the title suggests, I am moving to an electric kettle for my primarily single batch 30L boils. I will use a CB 70L stainless pot for the kettle though, as I plan to do double batches on occasion. My garage has a 15amp single phase circuit and a 20amp three phase circuit installed. I found this thread with options for a 3600w rig...

http://www.aussiehomebrewer.com/forum/inde...showtopic=62236

However im a bit lost as to what parts I would need for a 4800w rig. I have found 4800w elements, but am not sure what kind of controller I will need for it as the one listed in the above thread maxes out at 3800w.

Also, im not sure that I even need 4800w...im certain I wouldnt for singles, but with looking to do a few double batches I am wondering if 3600w is enough?

If anyone has built a 4800w kettle before I would love to hear how you went about it.

Cheers,

Brendan

 

[hotchilli]

If you want to run 3-phase, you will need an element bundle with a multiple of 3 elements, ie: 3, 6, 9 etc. For 4.8kW you'll probably only need a bundle with 3 elements. Each element will draw power from each of the three phases. The benefit of going this way is that you can get a nice low watts density bundle that won't caramelise your wort.

As for whether 4.8kW is enough - a quick calc shows that in a perfect world (no heat losses), it will take more than 1.5 hours to bring 70L of water from 20C to 100C. For 50L it will take about an hour.

 

[Maheel]

to control it you could use a PSR-25 from RS online, (buy the correct pot from them as well)
this is for the 15amp stuff, i have NFI about 3 phase


psr-25

i have one and it works well

a cheaper version (this is not a normal SSR) it might be triac based ?
http://www.uxcell.com/ssr40va-solid-state-...c-p-175259.html

these will "control the boil"

for both you would obviously need a sparky to make it safe and test

 

[YZ250]

Thanks for the replies.

Re heat up times, I will still run my current HLT so I would only be ramping from 65 degs to 100 degs...how long would this take with 4800 watts?

Ok, so each of the three elements would run off one of the phases and go back to a commmon neutral. Thats cool, how would I control these three elements? Is it possible to do it with 1 thermostat/simmerstat/potswitch? Or do I have to treat each element as an individual and buy three pots (one to control each). Is there a way I could use a PID in such a circuit?

I am assuming that flat out 4800w would be far too vigourous of a boil, and thus control is going to be needed.

You know what is starting to sound a lot simpler and cheaper....that is to build a 3600w setup as per the info thats commonly available, and use an immersion 2400w element running on a seperate circuit as a booster when im doing double batches.

Brendan

 

[Maheel]

i gas fire my kettle and also have a birko over the side immersion thing. Once it heats up it rapidly gets the temps rising.

i reckon 3600 + 2400 would be quick with the efficiency of all the internal elements :blink:

 

[hotchilli]

Re heat up times, I will still run my current HLT so I would only be ramping from 65 degs to 100 degs...how long would this take with 4800 watts?

25 min for 50L

The formula is:

time = ( volume * density * Cp * temerpature difference ) / (60 * power)

where

time is in minutes
volume is in litres
density is 1000 * SG (specific gravity)
Cp = 4.2
temperature difference = end temp - start temp in deg C
power is in watts

Ok, so each of the three elements would run off one of the phases and go back to a commmon neutral. Thats cool, how would I control these three elements? Is it possible to do it with 1 thermostat/simmerstat/potswitch? Or do I have to treat each element as an individual and buy three pots (one to control each). Is there a way I could use a PID in such a circuit?

I am assuming that flat out 4800w would be far too vigourous of a boil, and thus control is going to be needed.

You know what is starting to sound a lot simpler and cheaper....that is to build a 3600w setup as per the info thats commonly available, and use an immersion 2400w element running on a seperate circuit as a booster when im doing double batches.

I havn't looked into the control side of things yet. I'm in the process of building a 4v electric herms with 2x 3600W on two different circuits for the kettle(will get a sparkie to put in a 32A circuit eventually). I suspect 3600W will still be too much for a rolling boil and will probably need to implement some sort of variable control - it can't be to hard as every electric stove has it.

 

[QldKev]

I can't comment on the 3 phase side of things,

but with the element I think go big, it will only save you time on brew day. As long as you can throttle it back once you hit the boil.

For ramp up times, use the formula above or visit my website qldkev.net and under homebrew,calculators, you will find a water heating calc.

QldKev

 

[YZ250]

25 min for 50L

The formula is:

time = ( volume * density * Cp * temerpature difference ) / (60 * power)

where

time is in minutes
volume is in litres
density is 1000 * SG (specific gravity)
Cp = 4.2
temperature difference = end temp - start temp in deg C
power is in watts



I havn't looked into the control side of things yet. I'm in the process of building a 4v electric herms with 2x 3600W on two different circuits for the kettle(will get a sparkie to put in a 32A circuit eventually). I suspect 3600W will still be too much for a rolling boil and will probably need to implement some sort of variable control - it can't be to hard as every electric stove has it.

Thanks for that Hot Chilli, very useful. Also thanks Kev for the link to your site, handy calculators on there!

Those sorts of times are on par, or faster in fact, that what I get with my gas setup. I just lashed out on a 3600w element which will run via a 3800w voltage regulator to control power. Total cost for both these items delivered was $43...bargain. This setup is far cheaper and far easier than frittering around with my 3 phase - i'll leave that for my lathe and mill.

If I find the boil times too long in a double batch, I will drop in an over the side immersion element as a booster.

 

[booargy]

This setup is far cheaper and far easier than frittering around with my 3 phase - i'll leave that for my lathe and mill.

If you have 3 phases and a neutral then there will be 3 lots of 240v from phase to neutral. you can run three elements of equal value on each phase. I am not sure if this is right. you could run say 3 1200W elements and have the voltage regulator on the neutral which would control all three elements. this would spread the heat more.
if I had 3 phase I would give it a go. It may cost you $12 if it blows the reg.

 

[hotchilli]

Thanks for that Hot Chilli, very useful. Also thanks Kev for the link to your site, handy calculators on there!

no probs

Those sorts of times are on par, or faster in fact, that what I get with my gas setup. I just lashed out on a 3600w element which will run via a 3800w voltage regulator to control power. Total cost for both these items delivered was $43...bargain. This setup is far cheaper and far easier than frittering around with my 3 phase - i'll leave that for my lathe and mill.

If I find the boil times too long in a double batch, I will drop in an over the side immersion element as a booster.

where did you get the element and regulator - that's cheap? Is the element sheath incolloy 800 or just nickel plated copper? I just got ripped off last week (sort of) by an ebay seller who advertised a 300mm foldback element with a stainless steel boss, but was given a 200mm foldback element with a brass boss. The problem with this is that the watts density of the element will be higher due to the shorter length and corresponding reduced surface area, and as a result, the sheath temperature will be higher. A higher sheath temperature means more risk of caramelising the wort - although I haven't found any numbers on what's good for brewing, I do want to keep it as low as practical. I am getting a quote from TTE for 3x 1200W elements in a single boss which will have quite a low watts density, but I think it may be slightly more than $43!


also, how are you doing your element terminal enclosure? that's something I haven't sorted yet.

 

[Muscovy_333]

no probs



where did you get the element and regulator - that's cheap? Is the element sheath incolloy 800 or just nickel plated copper? I just got ripped off last week (sort of) by an ebay seller who advertised a 300mm foldback element with a stainless steel boss, but was given a 200mm foldback element with a brass boss. The problem with this is that the watts density of the element will be higher due to the shorter length and corresponding reduced surface area, and as a result, the sheath temperature will be higher. A higher sheath temperature means more risk of caramelising the wort - although I haven't found any numbers on what's good for brewing, I do want to keep it as low as practical. I am getting a quote from TTE for 3x 1200W elements in a single boss which will have quite a low watts density, but I think it may be slightly more than $43!

also, how are you doing your element terminal enclosure? that's something I haven't sorted yet.

Keen to hear where you picked up that element and reg as well...I'm working on a single vessel brewery at the moment.

 

[Whiteferret]

If you have 3 phases and a neutral then there will be 3 lots of 240v from phase to neutral. you can run three elements of equal value on each phase. I am not sure if this is right. you could run say 3 1200W elements and have the voltage regulator on the neutral which would control all three elements. this would spread the heat more.
if I had 3 phase I would give it a go. It may cost you $12 if it blows the reg.

Sorry this wont work you would have no control over the power used and it is a big no no to switch neutrals. If you want to go down the
3 phase route you could use a 3ph SSR or a 3ph contactor to switch it on and off with a PID temperature controller.
If you have a gpo on each phase you could have an immersion on each circuit for a total of 7200w which would get you up to temps pretty
quick but I find that juggling 2 elements hard enough. :icon_cheers:

ps: I've never looked for 3ph elements they would make it easy!

 

[booargy]

Sorry this wont work you would have no control over the power used and it is a big no no to switch neutrals. If you want to go down the
3 phase route you could use a 3ph SSR or a 3ph contactor to switch it on and off with a PID temperature controller.
If you have a gpo on each phase you could have an immersion on each circuit for a total of 7200w which would get you up to temps pretty
quick but I find that juggling 2 elements hard enough. :icon_cheers:

ps: I've never looked for 3ph elements they would make it easy!

Wasn't exactly sure if that would work.

 

[YZ250]

Re where I got the parts - as per this thread...

http://www.aussiehomebrewer.com/forum/inde...=62236&st=0

I got the element from Stove Connection for $25 + $9 postage, and then the temp controller from SiteDV88 on ebay for $8.54 including postage from Hong Kong

Stove Connection rang me up as soon as I put the order in to tell me they were out of stock on the straight element so I told him to send me the sickle shaped one instead.

Re how i'll cover up the terminal end - I think im going to put it all in a JiffyBox, including the voltage controller. Im not sure about earthing it though...my brother in law is a sparky so when I have everything mounted i'll get him over for the final wiring.

 

[DJR]

Density = 1000 * SG

Actually i think you are looking for SG / 1000 there. So SG = 1045 would be a density of 1.045 kg/L

 

[JaseH]

Re where I got the parts - as per this thread...

http://www.aussiehomebrewer.com/forum/inde...=62236&st=0

I got the element from Stove Connection for $25 + $9 postage, and then the temp controller from SiteDV88 on ebay for $8.54 including postage from Hong Kong

Stove Connection rang me up as soon as I put the order in to tell me they were out of stock on the straight element so I told him to send me the sickle shaped one instead.

Re how i'll cover up the terminal end - I think im going to put it all in a JiffyBox, including the voltage controller. Im not sure about earthing it though...my brother in law is a sparky so when I have everything mounted i'll get him over for the final wiring.

I must have grabbed the last one in stock! Sorry about that!

As for tidying up the terminal end, I'm planning on using something like these die cast alloy boxes from Jaycar and attaching the earth lead wire to the box.

http://www.jaycar.com.au/productView.asp?I...;SUBCATID=987#1

 

[YZ250]

I must have grabbed the last one in stock! Sorry about that!

As for tidying up the terminal end, I'm planning on using something like these die cast alloy boxes from Jaycar and attaching the earth lead wire to the box.

http://www.jaycar.com.au/productView.asp?I...;SUBCATID=987#1

Cool, you could polish those up too I imagine. Would the alloy box be in contact with the brew pot? My understanding is that we are looking for is a path (earth) for the voltage to run down in the even that the element fries, becomes live, and thus makes the whole pot live. How does it work on hot water systems?

 

[JaseH]

I havet got all the pieces together yet but the plan is to have the box and the kettle in contact so there is an electrical path between them. The only instance I see it would not is if you use a rubber/silicon washer between the box and the kettle and another one between the nut securing the element inside the kettle.

 

[pcmfisher]

I have just ordered one of those $8.54 voltage controllers. So cheap. Why not?
I will be interested to see how hot they get under load. That doesn't look like much of a heat sink to me. My prediction is they will melt down in no time. I could be wrong.

I would suggest plenty of ventilation for the jiffy box.

 

[YZ250]

Yeah Frothie I think I will do the same.

Will also ventilate well as suggested.

These regulators get hot when you choke down the volts yeah? It is my understanding that when running flat out they should be fine...however depending on how much one needs to dial back the current for a 60-90 minute boil thats when the heat could start building.