Electric Brewing Newbie Questions

[Microphobik]

Hi All,

I feel like many others around here who just discovered that electric heating elements were an option and am suddenly slapping myself in the forehead, wishing I had found out about it earlier. I am in New Zealand, where relatively week burners can run over $200, and the heavy weight of them makes shipping from the states not very cost effective. I've been hoping to upgrade to a few 100 Liter pots and have not been able to figure out how to affordably heat them. Then I found out about the heating elements

But I have a couple questions I was wondering if people could help me with...

1. I see that many use electronic control boxes, but am wondering if I really need one. My understanding is that the cheaper ones basically just regulate the temp. Is there anything wrong with just monitoring the temp like I do currently and turning off the heat when I hit my desired temp? I was planning on getting one of those popular 5500 w units that it seems most people use and getting a control box would dramatically increase the investment. Wondering how necessary it is.

2. Are their any major down sides to electric heating elements I should be aware of? At a glance it seems like a win win, but I wonder why everyone doesn't do it. Just the lack of fumes alone and the ease of brewing large volumes indoors makes it seem like a no brainer.

Thanks for any advice you might have in advance.

 

[kenh]

I assume mains power in NZ is 240V?

What amperage are your circuits fused for?

If 10 Amps then you can run one or two 2000 watt water heater elements - two if you put them on different circuits. Or if you can run a higher amperage circuit, look at the LWD or ULWD 240V water heating elements. But for those wattages you will need some sort of controller to regulate the heat you apply.

 

[Microphobik]

Thanks for the response. Unfortunately I know almost nothing about electricity, which perhaps is the down side? Doh!

We are 240 V. And we are on mains but we are very rural and the wiring may be a little eccentric as nothing in our house was set up traditionally.

I have no idea about the amps, circuits, etc. That said, I found a sort of map of the wiring that our electrician put in our curcuit board and it looks like there are two curcuits. Underneath each one it says 20A. Is it possible that means 20 Amps? Does that sound right? Our electrician is a friend but he moved out of the country, so I'll need to track him down to be sure.

So are you saying that if I buy one of those $250 boxes I see around, it will some how prevent the power from surging and I can use the heating elements no matter what my ampage is?

 

[Microphobik]

Hmmm, I just did some googling and it looks like NZ max is 10 amps. So the 20A must be something else. It looks like the max wattage is 2400 here as well. So would that mean that the 5500 watt unit is out, or does it just mean that I need onbe of those boxes? I guess I am unclear what they do exactly? Can anyone explain how this all works? I really know nothing about electricity.

 

[kenh]

Yep, 20A is 20 Amps. With 20 amps you can run a 4500 watt element but not a 5500 amp element.

But you can't just plug in a 4500 watt element because it will heat too fast. That's why you need one of the $250 boxes you see are around - you need to be able to turn the heat town or everything will boil over.

 

[Microphobik]

Okay, thanks. I'm struggling a bit to understand all this. But I contacted the electrician who did the work and it looks like we do have 20 amps. But he recommended I not go over 2400 watts. How much water can I get to a boil with 2400 watts?

I'm also a little unclear on how this works. According to Google houses in New Zealand have 10A and houses in the UK have 13. This is obviously not correct as ours has 20. It sounds like houses in the US vary a lot.

But what I don't understand is that all of these 240 volt devices I am seeing that have over 4000 watts require 30A. So how are people using them?

Is this the kind of thing where you can call your power company and get more power? I'm just a bit in over my head when it comes to understanding electricity. What am I missing?

 

[jeffmeh]

I believe you are confusing the amperage of the service going to a residence with the amperage of a single circuit within that residence. E.g., in the US we can see a 200a service going into a residence, and a service panel (with circuit breakers) that breaks that up into multiple circuits, at various amperages. The sum of the amperages for all the circuits will often exceed the 200a, with the assumption that one would never max them all out at once.

So what this really means is that if I want to run a device that can draw 30a, I need a 30a circuit. To get a 30a circuit, I need to have that available at my service panel, and I need to use breakers, wiring, and receptacles rated for 30a.

You probably have some 20a circuits, but your service to the residence will be more than 20a.

 

[Microphobik]

Thanks. I think you are right. I noticed that there were two circuits in this map that the electrician drew up and each said 20A underneath it. So it must be 20A on each one. I'll contact him again to clarify. So many houses have circuits that are greater than 20A?

Is there a heating element that someone could recommend that would work well for me, given that my circuits seem to be 20A? I'd like to heat as much water as possible, but haven't scaled up yet, so I can scale to whatever I am capable of heating, or just stick with my 5 gallon batches if that is all I can do. I'd preferably like something that is wired up and ready to go.

 

[ChocolateMaltyBalls]

Might be a good idea to check out this sticky if you haven't already: https://www.homebrewtalk.com/f170/electrical-primer-brewers-145019/

 

[Epimetheus]

Controllers - you can start without one and add it later. Then you probably want to add a recirc pump to ensure the mash temp is even. This stuff makes it easier for a price. Your wallet dictates the design.

I do E-BIAB without a temperature controller. It can be fussy if I don't hit the strike temp and have to manually heat up / cool down the mash. It is satisfactory for now. I will upgrade the system after I hit the lottery or sell one of the children,

 

[jeffmeh]

Thanks. I think you are right. I noticed that there were two circuits in this map that the electrician drew up and each said 20A underneath it. So it must be 20A on each one. I'll contact him again to clarify. So many houses have circuits that are greater than 20A?

Is there a heating element that someone could recommend that would work well for me, given that my circuits seem to be 20A? I'd like to heat as much water as possible, but haven't scaled up yet, so I can scale to whatever I am capable of heating, or just stick with my 5 gallon batches if that is all I can do. I'd preferably like something that is wired up and ready to go.

If you have 20a available, at 240v, the product of the two gives you the maximum wattage, in this case 4800w. If we were talking about an application where there would be continuous draw for three hours, you would want 20% headroom on your amperage, but in this case that does not apply.

And as others have stated, you will need some type of controller to regulate the power applied to achieve the appropriate level of boil vigor (boiling but not boiling over).

 

[kenh]

Okay, thanks. I'm struggling a bit to understand all this. But I contacted the electrician who did the work and it looks like we do have 20 amps. But he recommended I not go over 2400 watts. How much water can I get to a boil with 2400 watts?

I'm also a little unclear on how this works. According to Google houses in New Zealand have 10A and houses in the UK have 13. This is obviously not correct as ours has 20. It sounds like houses in the US vary a lot.

But what I don't understand is that all of these 240 volt devices I am seeing that have over 4000 watts require 30A. So how are people using them?

Is this the kind of thing where you can call your power company and get more power? I'm just a bit in over my head when it comes to understanding electricity. What am I missing?

I looked at my power panel and it is marked 200 Amp. but I know my uncle's is only 60 Amp. His house has screw in fuses and two main fuses in a pull out panel. Sometimes he blows one of his main fuses when he runs the dryer and cooks at the same time during the summer. My house was built 15 years ago and his was built a long time ago. I asked my brother in-law about this and he said modern houses all have 200 Amp power but a lot of old houses only have 60 Amp power.

A lot of brewers in the US use 5500 Watt elements - that's what I use. My brother in-law installed a 30 Amp outlet for my brew area and he told me there was no room for another outlet. I don't know if he meant he could not install another breaker in my panel or if the panel would not support another 30 Amps.

For you 240 Volts X 10 Amps = 2400 Watts and 240 Volts X 20 Amps = 4800 Watts. If you have a breaker or fuse it should be marked with 10A or 20A. Whatever it's marked should be what you have. If you really have 20 Amps than you can run a 4500 Watt heating element.

 

[Microphobik]

I looked at my power panel and it is marked 200 Amp. but I know my uncle's is only 60 Amp. His house has screw in fuses and two main fuses in a pull out panel. Sometimes he blows one of his main fuses when he runs the dryer and cooks at the same time during the summer. My house was built 15 years ago and his was built a long time ago. I asked my brother in-law about this and he said modern houses all have 200 Amp power but a lot of old houses only have 60 Amp power.

A lot of brewers in the US use 5500 Watt elements - that's what I use. My brother in-law installed a 30 Amp outlet for my brew area and he told me there was no room for another outlet. I don't know if he meant he could not install another breaker in my panel or if the panel would not support another 30 Amps.

For you 240 Volts X 10 Amps = 2400 Watts and 240 Volts X 20 Amps = 4800 Watts. If you have a breaker or fuse it should be marked with 10A or 20A. Whatever it's marked should be what you have. If you really have 20 Amps than you can run a 4500 Watt heating element.

Thanks, that helps. I think things are coming into focus. It appears that I have two breakers/circuits, each one having 20A each. I contacted the electrician who worked on our house and he said that he wouldn't recommend I use anything over 2400 watts. I assume to give me that head room in case...

Closest thing I can find is 2200 watts: http://www.trademe.co.nz/home-living/lifestyle/home-brewing/auction-664573768.htm

Any idea how much water something like this can bring to a boil, and in how much time?

 

[jeffmeh]

Thanks, that helps. I think things are coming into focus. It appears that I have two breakers/circuits, each one having 20A each. I contacted the electrician who worked on our house and he said that he wouldn't recommend I use anything over 2400 watts. I assume to give me that head room in case...

Closest thing I can find is 2200 watts: http://www.trademe.co.nz/home-living/lifestyle/home-brewing/auction-664573768.htm

Any idea how much water something like this can bring to a boil, and in how much time?

Unless he used wire undersized for 20a (which would violate code here in the US, and I assume there also), then I don't understand why he would suggest that at 240v you don't go over 2400 watts. As I stated earlier, you should be able to use a 4500w element with plenty of "head room."

An alternative would be to use both circuits and two elements, but given the above I don't see the point.

 

[Microphobik]

Unless he used wire undersized for 20a (which would violate code here in the US, and I assume there also), then I don't understand why he would suggest that at 240v you don't go over 2400 watts. As I stated earlier, you should be able to use a 4500w element with plenty of "head room."

An alternative would be to use both circuits and two elements, but given the above I don't see the point.

I honestly don't know. That's just what he said. Nothing would surprise me. We are very remote and everything is kind of duct taped together around here. Our water literally comes from a several mile long pipe that a few locals ran to a spring fed waterfall several decades ago. I would not be surprised to learn that the electricity was also set up in some odd, a-typical fashion. I know the neighbors are drawing off the same line as well. Different meters and circuits of course, but the same line. It's all odd, and over my head. I don't know enough to comment, but if my ceiling is 4800 watts, maybe he was just concerned that other appliances (refrigerator, stove, etc) would draw me over the limit. I don't think he said I couldn't, just that he wouldn't. For whatever that's worth.

Do you know how to calculate the heating power of that 2200 watt element I linked to by chance?

Thanks again for the help.

 

[dyqik]

As you say, the probable reason he said not to go over 10A/2400W on one circuit is that if your house only has 2 20A circuits, then there's a chance that the load from other appliances on each circuit is close to 10A already. The 20A is the total allowed load for everything on that circuit. Adding a e.g. a 15A element to 6A loads from other appliances will trip the breaker.

If you do decide you want more than 2400W, then you'd be best splitting it over the two 20A circuits to try to avoid this problem.

The heating power of a 2200W element is 2200W. There's a spreadsheet about that turns that into a time to strike and boiling temperatures for electric kettles, but the maths is pretty easy in SI units - it takes 4.2 kJ (i.e. 1000W for 4.2 seconds) to heat 1 litre of water by 1 deg C, so to heat 100L from 10C to 60C takes 21000 kJ = 1000W for 21000 seconds, or 2200W for 9500 seconds (just under 3 hours), or 4400W for 4800 seconds (80 mins), assuming 100% efficiency. Typical electrical immersion heating efficiency is around 90-95%.

For 100L/25 gallon pots, you'll need at least 5kW for heating in reasonable time and guaranteeing the ability to get a vigorous boil.

 

[Microphobik]

As you say, the probable reason he said not to go over 10A/2400W on one circuit is that if your house only has 2 20A circuits, then there's a chance that the load from other appliances on each circuit is close to 10A already. The 20A is the total allowed load for everything on that circuit. Adding a e.g. a 15A element to 6A loads from other appliances will trip the breaker.

If you do decide you want more than 2400W, then you'd be best splitting it over the two 20A circuits to try to avoid this problem.

The heating power of a 2200W element is 2200W. There's a spreadsheet about that turns that into a time to strike and boiling temperatures for electric kettles, but the maths is pretty easy in SI units - it takes 4.2 kJ (i.e. 1000W for 4.2 seconds) to heat 1 litre of water by 1 deg C, so to heat 100L from 10C to 60C takes 21000 kJ = 1000W for 21000 seconds, or 2200W for 9500 seconds (just under 3 hours), or 4400W for 4800 seconds (80 mins), assuming 100% efficiency. Typical electrical immersion heating efficiency is around 90-95%.

For 100L/25 gallon pots, you'll need at least 5kW for heating in reasonable time and guaranteeing the ability to get a vigorous boil.

Thanks, my head is about to explode from the math, but thanks

I have basically given up on the 100L idea for this house, at least with the electric set up. But I am still thinking about it for my 5 gallon set up. For that I usually start at about 25 liters. I can't quite follow the equation, but would it be as simple as dividing it by four? IE, 45 minutes to boil 25 Liters? Sorry, I'm a dunce when it comes to math. Add electricity and forget about it

 

[dyqik]

Yes, 45 minutes sounds about right for 2200ish watt to heat 25l of water from 10C to 60C, or from 60C to boiling.

The maths really is simple... energy (J) = weight of water (kg) x 4200 x temperature change (C); and power (W) = energy (J) / time (s).