Electric elements

[hughjamton]

Will a 2kw "long" element, such as from a washing machine, be less likely to burn the wort than a 2kw "short" element, such as from a cheap kettle?

 

[The Baron]

You would think so as the heat is shared out on a longer element but I am sure a sparky will confirm or not.
I do not use more than 1900wattts in my system to help with scorching and it does help although boiling time takes slightly longer

 

[hughjamton]

You would think so as the heat is shared out on a longer element but I am sure a sparky will confirm or not.
I do not use more than 1900wattts in my system to help with scorching and it does help although boiling time takes slightly longer

I was thinking of a total of around 3kw, maybe 2 at 1500w.
They'd go into a 50ltr stainless pot, although I'd be aiming at about 27ltr into the FV.
Do you think 1500w would hold a boil?

 

[The Baron]

In all honesty I do not know but plenty have built there own units so sit and wait for a answer from one of the builders/sparkys

 

[Gerryjo]

You would be better with a low density heating element which will give the same heating output but spread across more surface area which will decrease the potential for burning/charring of the element when in contact with sugary wort.
Screwfix keep a few in stock and worthwhile looking into.
https://www.screwfix.com/p/tesla-ti...11/56481#product_additional_details_container

 

[hughjamton]

You would be better with a low density heating element which will give the same heating output but spread across more surface area which will decrease the potential for burning/charring of the element when in contact with sugary wort.
Screwfix keep a few in stock and worthwhile looking into.
Tesla Titanium Immersion Heater Element 11

Please understand you are talking to the ignorant here so please be patient and tell me when I'm wrong.
This will be a mash tun and boiler combined, brew in a basket eventually, but a bag until I sort the basket.
The Screwfix element is 3kw which is the total I was after (I think).
I thought 2 lower powered washing machine units may have been better so I could turn one off once it reached boil?
The Screwfix one has a thermostat, would I be able to make use of it or would I bypass it?

 

[Bill_g]

My gut feeling would be that you are on the right track using two low heat density elements to spread the heat. I had a quick look at the Screwfix immersion heater and personally I'd say it is unsuitable, the hole you will need to cut will be very large and it will be difficult to seal to the curved surface of your pot.
With all electric elements, to avoid wort burn on,you will need to control the power delivered to the element. This is normally done using a power controller such as can be found on eBay or Amazon (search for '220V AC 4000W SCR power controller'. Essentially these devices are an electronic switch that allow an adjustable percentage of the AC waveform to pass so controlling the power delivered to the load. You could either control the elements as a pair (totalling 4000W or as the controllers are cheap you could use one per element. Two might be easier allowing you to use two 13A sockets which are only rated at 3kW each.
This would all be a bit experimental and require wiring up safely taking care with earthing. Also ensure you are using a mains supply fitted with an earth leakage trip. Almost all will be these days but always best to check.
If you are not familiar with good wiring practices etc it would pay to try to find a local electrician to give you some advice & check your work.
(I personally use a propane gas burner but I think the above should work quite well with a total of 4kW of controlled heat available allowing you to ramp up the power to minimise wort burn. I'm a retired electrical/electronics engineer, happy to advise on technical issues if I can help)

 

[DCBC]

I may myself be wrong but I understand that there is no structural difference between a low density element and a standard element. The LWD/ULWD elements are just designed to have a larger surface area, as Gerryjo says, and this spreads out the heating, meaning that no part of the wort is ever in contact with enough watts to scorch it.

So in answer to your question, the (physically) larger the element, the safer you are. I have a couple of BrewPi's round elements and they are superb. Never had a problem with overheating or scorching. In fact, one of them survived a (brief) dry firing without any problem at all. They are probably more expensive due to Brexit now but they are worth it

https://store.brewpi.com/mashing/stainless-steel-heating-elements/round-element-kits

 

[Bill_g]

I may myself be wrong but I understand that there is no structural difference between a low density element and a standard element. The LWD/ULWD elements are just designed to have a larger surface area, as Gerryjo says, and this spreads out the heating, meaning that no part of the wort is ever in contact with enough watts to scorch it.

So in answer to your question, the (physically) larger the element, the safer you are. I have a couple of BrewPi's round elements and they are superb. Never had a problem with overheating or scorching. In fact, one of them survived a (brief) dry firing without any problem at all. They are probably more expensive due to Brexit now but they are worth it

https://store.brewpi.com/mashing/stainless-steel-heating-elements/round-element-kits

I agree, it's just that some elements are wrapped up to fit in a small space e.g. a kettle. Water can't burn but the noise they make is steam bubbles forming on the element, so wort would tend to burn unless power turned right down. Also would be hard to clean.
Those BrewPi elements look absolutely ideal.

 

[Gerryjo]

I may myself be wrong but I understand that there is no structural difference between a low density element and a standard element. The LWD/ULWD elements are just designed to have a larger surface area, as Gerryjo says, and this spreads out the heating, meaning that no part of the wort is ever in contact with enough watts to scorch it.

So in answer to your question, the (physically) larger the element, the safer you are. I have a couple of BrewPi's round elements and they are superb. Never had a problem with overheating or scorching. In fact, one of them survived a (brief) dry firing without any problem at all. They are probably more expensive due to Brexit now but they are worth it

https://store.brewpi.com/mashing/stainless-steel-heating-elements/round-element-kits

Those elements would be perfect for use though the price reflects this as they are custom designed for home-brewing and can utilise a 13a supply for a domestic setup and with an SCR you can vary the voltage to limit the input this controling the heat.

 

[hughjamton]

Thanks chaps. Sorry I'm a bit late coming back, I've been putting a slate roof over my wood fired oven then decided I needed a beer so I've been in my bar watching telly.
The round heater is way out of my budget, looks good though.
So my assumption that the longer the element the more the heat spreads is correct, go me!
So, I would like to keep it to 3kw or below if that's practical in my 50ltr pot? I won't be brewing 50ltr more like 27ltr ish into the FV.
Would I be better off with one element at 3kw, or 2 elements totaling 3kw?

 

[ppsmith]

Two elements gives you some redundancy - if one burns out mid brew you might be able to limp home on the other one.

I fitted a single 3kW (total) element to my kettle, but it’s actually 3 separate 1kW elements in a single fixture. Details here if that helps -3kW AliExpress Element

 

[hughjamton]

Two elements gives you some redundancy - if one burns out mid brew you might be able to limp home on the other one.

I fitted a single 3kW (total) element to my kettle, but it’s actually 3 separate 1kW elements in a single fixture. Details here if that helps -3kW AliExpress Element

That looks very interesting.
A couple of questions, did you cut your hole with a Q max cutter? The link to your power controller isn't working, do you have another link? I take it that you took the brass plates between the elements off then wired them individually into your box? Would you be kind enough to draw, very simply, how you connected it all in the box? I can't emphasize the word simply enough.
I'm going to use it as a biab, basket not bag. At the moment I insulate really well and I don't have a problem with temperature, however, I will eventually want temperature control but that's another language to me, even your post turned into Chinese writing.
How is your setup performing, have you made any other changes?
How big are your brews?
Thanks in anticipation.

 

[ppsmith]

No worries. Yeah, I bought a Q-Max cutter for the job - even that was a struggle to get through the steel.

The power controller is one of these "4kW" ones. No way I'd trust it up to that power level, but as it's only controlling a single element it's well within it's specification.

Removing the brass plates does isolate each element. After that you just wire each switched pair of cables to an individual element. You'll need a crimp tool and ring terminals to do this safely (red, 4mm rings If I remember correctly). Make sure the body of the element has a position to attach an earth wire to (some don't from what I can see), and make sure the earth is the longest wire so that if things start pulling loose that would be the last one to disconnect. The housing also needs a cable gland for strain relief so that any movement on the cable is not pulling on the connections.




The crimp tool will also come in handy as the switches have male spade terminals, which is probably a better option than soldering anyway.

I put a 7 pin socket/plug between my control box and the element to allow it to be disconnected when I want to clean it etc, but I guess that's optional. If you don't have the socket though you'll need another cable gland where the 7 core flex enters the control box.

In terms of wiring, this is as simple a diagram as I can make. I've omitted the variable control as you said it's not essential for you at this point.

Once it's all wired up and connected, it's ESSENTIAL to ensure that there's earth continuity from the earth pin on your plug, right through to the kettle (if it's metal), or at least the element if not. If something goes wrong, you do not want that to be live at mains voltage when you touch it.

My kit is currently packed away, but I can take some photos of the wiring details when I pull it down next if needed.

Hope that helps.

 

[hughjamton]

No worries. Yeah, I bought a Q-Max cutter for the job - even that was a struggle to get through the steel.

The power controller is one of these "4kW" ones. No way I'd trust it up to that power level, but as it's only controlling a single element it's well within it's specification.

Removing the brass plates does isolate each element. After that you just wire each switched pair of cables to an individual element. You'll need a crimp tool and ring terminals to do this safely (red, 4mm rings If I remember correctly). Make sure the body of the element has a position to attach an earth wire to (some don't from what I can see), and make sure the earth is the longest wire so that if things start pulling loose that would be the last one to disconnect. The housing also needs a cable gland for strain relief so that any movement on the cable is not pulling on the connections.


View attachment 44255

The crimp tool will also come in handy as the switches have male spade terminals, which is probably a better option than soldering anyway.

I put a 7 pin socket/plug between my control box and the element to allow it to be disconnected when I want to clean it etc, but I guess that's optional. If you don't have the socket though you'll need another cable gland where the 7 core flex enters the control box.

In terms of wiring, this is as simple a diagram as I can make. I've omitted the variable control as you said it's not essential for you at this point.

View attachment 44256

Once it's all wired up and connected, it's ESSENTIAL to ensure that there's earth continuity from the earth pin on your plug, right through to the kettle (if it's metal), or at least the element if not. If something goes wrong, you do not want that to be live at mains voltage when you touch it.

My kit is currently packed away, but I can take some photos of the wiring details when I pull it down next if needed.

Hope that helps.

Thanks for your detailed response.
This looks like the way I'll go.
Just a couple more questions if that's ok.
The link to the voltage controller shows a lot of different ones, was there one that's preferably?
Do you think that I could connect one of the other 1kw sections to an inkbird for the mash? I'm thinking of getting a pump for recirculating.
Are those switches just on the live wire?
Photos would be great the next time you get the kit out.
Once again thanks for your help.

 

[ppsmith]

Thanks for your detailed response.
This looks like the way I'll go.
Just a couple more questions if that's ok.
The link to the voltage controller shows a lot of different ones, was there one that's preferably?
Do you think that I could connect one of the other 1kw sections to an inkbird for the mash? I'm thinking of getting a pump for recirculating.
Are those switches just on the live wire?
Photos would be great the next time you get the kit out.
Once again thanks for your help.

I think the controllers are all pretty much the same design. The metal cased ones are safer as there's less chance of sticking anything into the dangerous bits.

An Inkbird with an SSR would handle a 1kW element easily. Presumably you're thinking of the ITC-100?

The switches are all double pole, so both the live and neutral are disconnected when off (and there's a neon indicator in them to show when they're on)

Pics of the setup as requested:

 

[hughjamton]

Brilliant, thanks.
I've ordered all the components, except the 48mm q-max cutter, I'm looking around for a good price, goes against my nature to spend upwards of £30 on something I'll only use once.
Going by the speed of normal deliveries from China, I've got time to look.
They do a cheap 42mm hole saw for stainless but my pot is very good quality and 1.6mm thick, so I'd have no confidence it would be capable of cutting a neat hole.