thanks for ideas, might insulate with yoga mat or camp mat and try again. will check how flameable that material is just for saftey. also this might sound silly but why does everyone boil with lid off? wouldnt u have less evaporation with a vented lid and close watch of boil ? and therefor less water to begin with? i have yet to put my first biab down yet so this question is probably silly. thanks and cheers.

thanks todd, good info, will hopefully put down first biab in a couple of weeks, cheers.

Hi Andy,

Just in case you haven't yet sorted out your problem, I've been through it too.

I've done 18 batches in a 40L electric urn with a 2000 W element (10 amp plugs in NZ ....) & it's definitely NOT up to the job. My first batch was a complete fiasco as I couldn't get it to boil!!!

My solution is to use the urn element together with an over the side 2500W element when I'm bringing temperature up & that does the job fine. To maintain a boil, I use the 2500 W & turn off the 2000W. Given the limitations of the fuseboard in my house, the 2 elements have to be plugged into sockets that are on different circuits on the board.

Both elements are exposed in the wort but I've never had a problem with scorching. I use a SS wire rack ( cannibalised from a broken electric casserole ) to keep the voile off the element. All a bit Heath Robinson but it works fine & makes great beer.

If I was building a 50 L urn, I'd go for 1 x 2000w element & 1x 3000w element.

One word of caution about insulating the sidewall of the urn with a camping mat. I have tried that & its not the ideal material. The dense blue rubber tends to adhere to the urn when hot & you end up having to scour patches of it off the urn afterwards with a steel pad! It might work better if you used a mat with a metal foil laminate on one side, but I can't speak from experience.

Mike

shibolet wrote:i tried using my 1500W X 2 elements on a 10 amp plug. it melted...

Hi Shibolet

Yes , it would do:

maximum voltage in NZ ( which all certified appliances & systems must be able to cope with ) is 230v + 6% = 243.8 v

3000W / 243.8v = 12.31 amps on a 10 amp plug = 23.1 % over spec' = meltdown.

My heavier element is 2500W / 243.8v = 10.25 amps = 2.5% over spec' , which is within safety limits as I'd expect, as the over the side element is sold prewired with a 10 amp plug as a NZ certified appliance.

The key point as I said in my post, is to keep the 2 elements on separate plugs, separate sockets & if necessary, separate breakers in your fusebox, so that the 2 cannot create a joint overload. My breakers are 16 amp. 4500W / 243.8v = 18.46 amps. So I have to connect the 2 elements into different sockets that are on different breakers.

If I went to a 3000W element, I would have to get a sparky in to upgrade a socket to a 15amp type & put the 3000W element on a 15amp plug, otherwise I'd be creating a fire hazard.

Sorry for not explaining this clearly enough in my last post.

Mike

PS

In Australia, the maximum legal voltage on the grid is 230v + 10% = 253 volts, so you have a little more headroom. 2500 W is now a pushover. Even so, 3000W / 253 volts = 11.86 amps = 18.6 % over spec' , so I'd definitely still upgrade to a 15 amp plug & socket.