Cheap Kettle Elements (a cautionary tale)

[bob downe]

I just spray the element with something acidic like lemon juice for a couple of hours. It seems the crud is quite alkaline in our area.

The crud just falls away after that.

[sparky Paul]

Under standardised euro-voltage (230v) then a 3kw element on a 13A supply is an overload - good job the voltage sits at ~240v 90% of the time and 13A fuses arent insta-blow at their limit In practice it should run fine from a socket outlet (there are tens of thousands of immersion tanks bubbling away happily out there) - but plug DIRECT into the socket, dont use an extention lead as voltage drop will increase the current loading.

The optimal solution is to run a dedicated single point spur direct from the ring main and use 16A commando plugs and sockets for the boiler

An element rated at 3kW for a 230V supply will indeed nominally exceed 13A, but only marginally. However, running the same element at 240V will definitely exceed 13A (it'll draw around 13.6A). I think what you meant to say is that an element rated at 3kW for a 240V supply will be OK when run at 240V (and also at 230V of course).

Also, if using an extension lead, the extra voltage drop will reduce the current drawn, not increase it.

Herr Ohm would be turning in his grave.

Indeed!

All immersion elements are rated at 3KW @ 240V, and 2.7KW @ 230V.

240V is still the nominal voltage in the UK regardless of what the standards say, average supply voltage in mainland GB is around 242V, and 239V in NI, which conforms to the old standard of 240V ±6%.

The 230V (+10%/-6% in the UK) 'harmonisation' is simply a fudge to make sure all the different European supplies fits the standard. In countries where the nominal voltage is 220V, they use use a harmonisation spec. of 230V -10%/+6% instead. The eventual aim is to harmonise on a standard 230V ±6%, as supply transformers are gradually replaced.

[Deller12]

Not an AG brewer but I spend my life working with immersion elements TBH you're only looking at spending about another £5-£7 for a proper 11" Superalloy immersion element - and those will keep up with boil after boil as its what they're intended for.

Are they designed to boil ? I thought they were only set to heat the water to around 60-70 deg

[themadhippy]

good ole 'harmonisation, i wont mention the large arena near Birmingham,nor the very large plassma screens, funnily enough made by the company now sponsoring said venue,but lets just say screens flown straight in from the european leg of the tour, set at 230V get upset and let the magic smoke out when the voltage is sitting at 252v.

[Spud395]

A real spot the 'sparks' topic this one

[raiderman]

Before the new boiler I was brewing in an old but fancy tea urn, which had a bloody great element in it, run off a normal plug. As evidence that domestic power supplies aren't designed for this I now have a blackened socket and a wife who has got it into her head that this spoils the look of her her new kitchen. The new boiler goes with 2 2.75kg old fashioned kettle elements which are separately wired and run off different sockets so no overload problems. If you're thinking about running anything chunky off a normal household supply its probably worth checking it out with someone who understands this stuff

[Pinto]

Not an AG brewer but I spend my life working with immersion elements TBH you're only looking at spending about another £5-£7 for a proper 11" Superalloy immersion element - and those will keep up with boil after boil as its what they're intended for.

Are they designed to boil ? I thought they were only set to heat the water to around 60-70 deg

Only because the tank stat will cut out at 60/70 degrees as set - the element itself will boil away happily. End of the day, its all about the quality of construction - a kettle element isnt designed with a 100% duty cycle in mind and is made to heat 3l of water...immersion elements are designed to heat 150+l up and maintain that set temp indeffinately.

I've attended the effects of a failed tank stat on a number of occasions - best case being a bathroom sauna and worst case when they discharge into the cold water tank in the roof and cut through it like a hot knife ! (resulting in several hundred gallons an hour of mains pressure cold water taking a short cut to the drains through your building !)

[orlando]

The new boiler goes with 2 2.75kg old fashioned kettle elements

Bloody hell they are chunky, what wattage are they then