Electric Keg Boiler, 240v specific, Two Elements

[BakerBoy]

I’ve used the google search on this forum, and read everything about electric kegs/ heating/ elements – yet it is amazing how confused one can get with all the different countries voltages, different maximum amps allowed, etc… so I thought it would be good to have a 240v specific (New Zealand / Aus) answer to this subject!

I’ve explained my setup and the type of still I want to run below… any advice from those with electrical knowledge is greatly appreciated.

I would like to keep it specific to 240v & keep it simple with no temp control devices.

The purpose of this is to confirm my thoughts – and to provide clear information to people who search for this in the future.

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I live in NZ – where we only have 240v

I want to install 2 heating elements into a 50l keg boiler

1,000watt + 2,000watt

I want to use my still to first strip my wash with minimum reflux… and then run a slower 90% reflux to get as high & clean ethanol as I can.

So ideally I would use my elements in the following manner

Heat up/ Bring wash to the boil ---> Both elements total of 3,000watts
Stripping the wash with no reflux ---> Only the 2,000watt element
High Reflux final run ---> Only the 1,000watt element

Once boiling temp is reached, I would simply like to unplug one of the elements – depending on if I’m stripping or refluxing… Ideally I do not want to build any sort of circuit, switch or variable control, just keep it real simple…

I will be running a 25 or 30-liter wash, using a 50-liter keg with a 50mm(2”) wide column (1.2metre long) – so from what I’ve read a 1,000watt element is acceptable(just) to run a reflux column of this size.

My Question:
If I wire each heating element to a separate plug (i.e. there will be 2 plugs coming out from the still) and plug both into a double adapter (same wall socket) will this overload my system and potentially blow a fuse?

This seems like such a simple question, but there really is conflicting and confusing information on this forum about this topic!

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In “The Compleat Distiller” book (page 86) it says:

“If only 240v power is available, then you can use two elements and use them independently or both together, either in parallel or in series… as with 240v it is safe to plug into just one wall socket.”

But then it talks about wiring a switch that allows running both in parallel or series – I don’t want to wire any switches

It then says -

you can run any combo of 1000w, 2000w or 3000w “off a 240v, 15 amp power supply… Any combination larger than 3,500watt requires at least a 20amp circuit”

I assume the standard power socket in my wall is 15amp?
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This kind of answers my question – but I’m looking for feedback from those that have been running stills with 2 heating elements on 240v!

How are others running a simple duel element setup? (with no switches or variable controllers)?

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This is my first post - I've devoured several books over the last few weeks, and fairly confident I've got the theory all sorted - its just this electrical heating issue that has me slightly confused!

[Dnderhead]

youd have to use maltabul plugs, pluging in the combanation you want, even diferant curcits.this is not a good idea,as plugs are not made as switches and it will shortion ther life.

[myles]

You are only looking at 1 side of the story. My first still used a standard 13A 240v kettle element running straight off the socket as you describe. Well within the capacity of the circuit.

You would be shocked at how hot the cables got. The circuit is rated for normal use. Running the element continuously for a few hours is not normal use. I would have to say that you should run any type of electric still on a COOKER circuit. 40-50 Amps.

Also I think your powers are too low. I usualy run 3kW to heat up and about 2kW when in pot still mode. Lower for the reflux column.

On the new keg I am thinking of putting in two 3kW elements to warm up on 6kW, and turn 1 off for the run.

[BakerBoy]

youd have to use maltabul plugs, pluging in the combanation you want, even diferant curcits.this is not a good idea,as plugs are not made as switches and it will shortion ther life.

I googled "Maltabul plugs" and got nothing... i assume this is a typo? - Are you referring to UK/Euro plugs with fuses built into them (hence a somewhat meltable plug?)

I don't understand what you mean by "plugs are not switches" - a switch is simply off + on right? - so why not just plug or unplug instead of wiring a switch?

In "the Compleat Distiller" book - the switch they build looks to be for convenience of changing element setups (between individual, parallel, series) - there are no fuses - and this just plugs straight into a standard wall socket!?

[BakerBoy]

You are only looking at 1 side of the story. My first still used a standard 13A 240v kettle element running straight off the socket as you describe. Well within the capacity of the circuit.

You would be shocked at how hot the cables got. The circuit is rated for normal use. Running the element continuously for a few hours is not normal use. I would have to say that you should run any type of electric still on a COOKER circuit. 40-50 Amps.

(i could be wrong on this)... But I'm pretty sure in NZ household electrical circuits are rated at 15amp (except ovens which are on like you said a higher amp cooker circuit)... However all plugin appliances are restricted to a maximum of 10amps - my heating elements are 10amp

My electrical math is somewhat limited, but Ohms law suggests your kettle element at 240v & 13amp was 3120watts - i assume by "kettle" you mean it was designed for boiling water for coffee & tea etc... these are small elements designed to boil a 2 liter container for a short period of time - So can i assume your plug got hot due to this misuse and the high amp rating?

i will be using the proper low pressure, hot water cylinder elements designed to heat large volumes of liquid for longer periods!

Also I think your powers are too low. I usualy run 3kW to heat up and about 2kW when in pot still mode. Lower for the reflux column.

On the new keg I am thinking of putting in two 3kW elements to warm up on 6kW, and turn 1 off for the run.

I'm confused - You say my powers are too low - but you then state you use the exact same powers for your own still... everything i've read in books and this forum suggests 750watt-1000watt is acceptable for a 2" reflux column - yes 3kW is limited for warm-up - but i have to compromise - as anything over 3,400watt requires an electrician to install a higher amp circuit - so i can live with a 3000watt maximum heat up element!

Thanks for your input Myles - every little bit of other peoples perspective helps me get closer to a solution

[myles]

No you missunderstood. The entire cable run got hot. You could feel it both in the cable between the still and the socket, and also radiating through the plaster in the wall. The problem is not in the element, but in the way the circuit wiring is designed. It is not intended for the main circuit to be in continuous use for long periods.

The element in your oven is probably only 3kW but it is expected to be switched on for longer time intervals. That is why they upgrade it to 40A cable. As for the other issue, each circuit on the ring main has a TOTAL load. If you pluged 5 kettles into 5 different sockets but on the same ring at the same time your wiring would get hot.

I am suggesting that your 2 elements want to be on separate circuits back to the distribution board - or plug them both into your cooker circuit which can handle it with ease.

You can manage fine with 3kW total but it is a bit slow to heat up. A better arrangement would be a 3kW element on 1 circuit and a 2kW on a different circuit. I know you didn't want to bother with a controller but it does make life much easier. 2 parallel elements is good sense. If 1 burns out you can still keep going. If you want to save costs on the fittings (often more expensive than the element) you can get (expensive) 3 phase industrial elements. These have 3 elements wired into 1 fitting with a choice of connection options.

[kiwistiller]

Pretty sure your wall socket (and a lot of household circuits) are 10amp max It sucks. Where are you at?

[BakerBoy]

Hey Kiwistiller - I'm in Wellington ... i read on some nz govt energy website that you ideally want to install 10amp fuse wire in the standard fuse's - but never use over 15amp! ... so i assumed they were max 15 amps!?

Geez - i must be pushing my wiring without realising it then - cos in my office i run 2x 400watt PC's + moniters, a freakin huge stereo amp & sub - and in winter a 2.4kW oil column heater & when its real cold - i boost a second 2.4kW fan heater all from one room (2 wall sockets with a 6way plug extension board on each)! ... i guess that is why all this confuses me - cos i've never really paid much attention to what watt & amp things are! - i've been doing that for 9yrs and never popped a fuse!

How do the people in "The Compleat Distiller" do it then? - the plug they build is simply for convenience so its easy to switch between independant, parallel & series (the guy is from NZ and plugs it into the standard socket!) - there are no fuses, or (for lack of better words) reducers in it - just wires and switches (see pic)

[olddog]

Get your electrician to install a 15amp , the socket looks the same but the earth pin is larger to prevent 15amp devices being plugged ito a 10 amp socket.

[BakerBoy]

Myles,
Cheers for that dude - your explanation makes total sense now

See the attached pic in my previous post (above) - "The Compleat Distiller" - pg 86... this is where i got my logic from - they don't seem to worry about plugging a dual combo of a 1kW + 2kW into the same wall socket!?

[MuleKicker]

youd have to use maltabul plugs, pluging in the combanation you want, even diferant curcits.this is not a good idea,as plugs are not made as switches and it will shortion ther life.

I googled "Maltabul plugs" and got nothing... i assume this is a typo? - Are you referring to UK/Euro plugs with fuses built into them (hence a somewhat meltable plug?)

I don't understand what you mean by "plugs are not switches" - a switch is simply off + on right? - so why not just plug or unplug instead of wiring a switch?

In "the Compleat Distiller" book - the switch they build looks to be for convenience of changing element setups (between individual, parallel, series) - there are no fuses - and this just plugs straight into a standard wall socket!?

He meant "Multiple" And plugs are not made to be switches. Plain and simple. Pulling a plug with current flowing causes an arc between the prongs and the outlet. doing this over and over will cause fretting of the terminals and they will wear out. Worst case scenario, there will be high resistance in the outlet, causing heat, possibly fire.
To make a long story short: Switches are simple and easy to install. I suggest you do it.

[BakerBoy]

@MuleKicker

Haha... cheers for that ... that makes sense now.

Ok i've slightly confused people with my terminology - i should have used the term 'control box' instead of 'switch' - i would of course turn the switch off at the wall - i just didn't want to confuse the 'wall socket switch' with the 'control box switch' that "The Compleat Distiller" suggests building... so the best thing i came up with was plug & unplug... i see now that it was confusing!

Damn... i was trying so careful to be as clear and precise as possible!

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Something i didn't know until today...
Compleat = "Of or characterized by a highly developed or wide-ranging skill or proficiency"
Complete = "Having all necessary or normal parts, components, or steps; entire"

[MuleKicker]

its pretty easy to do, with all the diversity here.

[BakerBoy]

Alrighty...
I drew up a diagram of all the rooms in my house, marked out where all the wall sockets are... then spent a couple hours pulling each fuse... then going around checking with a lamp which sockets are on which electrical circuit*.

*Note: i don't know if im using the term "circuit" here correctly - my meaning here refers to a circuit being all the wall sockets attached to a single fuse.

My house is only 20 yrs old... Either my Electrician was lazy or rather clever! ... my entire house is run on 3x 20amp circuits! (kiwistiller above suggested the norm in NZ is only 10amp! - lucky me )... there are 4 other 15amp fuses dedicated to individual appliances (dishwasher, bathroom heater, ensuite heater & spa bath - i guess its because these are all in potentially wet areas and have heating elements in them!?)

Now... what im happy about - is i now know that i can run an extension cord from the spa-bath wall socket and have peace of mind that there is nothing else drawing current from that circuit.

So my conclusion from all your helpful comments above - is i could safely run up to a 3kW 240v element over this 15amp dedicated circuit.

On a side note - What i don't get is the 3kW element i was looking at in the shop was rated at 10amp - would there be some sort of resistor or something built into it? - I don't get it cos Ohms law suggests 3,000 / 240 = 12.5amps!

I will also run a 1kW element plugged into my normal garage wall (20amp socket - which i now know exactly what rooms / appliances are also on that circuit - i just need to make sure im not also running the washing machine, clothes dryer, my office PC, heaters and stereo at the same time )

Now i just need to do more reading to decide what element setup is best/suited for 20-30 liter strips & neutral reflux... i was originally thinking 1kW + 2kW... but now that i know i've got the fuses to handle it im thinking a 1kW + 3kW

Warm up --- 4kW total
Stripping --- 3kW
Reflux --- 1kW

If i'm totally missing the plot here, feel free to chime in and set me straight... i'm here to learn & share

Thank you friends... I would usually stumble at this point, then give up putting it in the "this is too hard basket" - but with all the knowledge sharing going on at this forum its giving us over-excited beginners a hand jumping over our own lil hurdles

[myles]

For warm up and stripping throw as much power at it as the wiring can cope with. If there are solids in solution you might want to warm up a bit slower, to allow circulation to establish, to stop stuff sticking to your element surface. Or use a forced circulation technique.

For the reflux, power input is linked to column diameter. Somewhere between 1 and 2 kW is to be expected. A controller is worth it for the precise control it permits.

[LWTCS]

Need 19 amps for a 4500 watt element. #12 wires are cool but # 10s would be less likely to get,,,,,,,,warm. 20 amp breaker would be good. Not enough margin in my area( if I cared about staying compliant),,,,,,( which I am).

I run # 10s on a 30 amp breaker. Everything stays cool as a cucumber.........cept my boiler

Also helpful if you could keep your cords as short as possible to reduce resistance.

Where is the service panel in relation to your stilling area?