Recs for Extension lead please

[Bertie Doe]

To safe my marriage, I need to move my new beer brewing machine from kitchen to bathroom - that's a mere 10 metres for an extn lead. The maximum heating element drain on the brewer (if that's the right word) is 2200 watts.

The following Youtube guy, has been banished to the garden (in February !!), he's using an extension but hasn't mentioned the extensions' rating. See Brewday # 1, fast-forward to about 18 minutes :-

So what's the minimum rating for a suitable 10 metre lead - 10, 15 or 20 amp please. TIA.

[Harry Bloomfield]

Bertie Doe formulated the question :

10amp should cope with that.

[Harry Bloomfield]

It happens that Harry Bloomfield formulated :

But usually it will be a 13amp rated extension. Make it is supplied via an RCD and the lead is fully uncoiled too.

[tabbypurr]

2.2kW is just under 10A

NT

[Martin Brown]

I would be more worried about having something permanently on power and using an extension lead into the bathroom - where there are strict regulations about not having power sockets!

Is there no other place where your contraption could live?

[Harry Bloomfield]

I have just noticed he said 'bathroom' - that is a definite no, no!

[tabbypurr]

depends on the size of the bathroom & whether it's suitable for a damp location.

NT

[Dave Plowman (News)]

W 2200

--- = A So ---- = 9.6A V 230

[John Rumm]

Sounds like you need a normal 13A lead. Jojo do quite neat units in a cassette format with a couple of sockets on.

[Bertie Doe]

Thanks all, it looks like the bathroom is not a good idea, although the bath itself is fibreglass and some distance from the shower unit.

There's a small covered area (porch), reachable from the kitchen with a 10 m extn lead. Probably the best bet.

Thanks John, the Jojo 10 m extn 13amp looks a good price for about £15, which includes vat and a £3.50p handling fee.

[tabbypurr]

ask them not to handle it :)

NT

[John Rumm]

Much depends on the layout and the size of the room. If it could be tucked out of the way in an airing cupboard for example, then its low risk. If you have to clime over it to get into the shower, less so ;-)

[Malcolm Race]

A cassette lead isnot a good idea as the lead needs to be fully unwound for this rating, to avoid inductive heating. With acassette lead there will always be the temptation to wind in any spare.

Malcolm

[Johnny B Good]

The issue of unwound extension cables overheating has nothing whatsoever to do with *inductive* effects. It is purely a matter of concentrating the cable into a compact, low surface area lump which reduces the heat dissipation rate of the I squared R losses in the cable when carrying its fully unwound maximum rated current.

The reduced dissipation rate results in a much higher temperature equilibrium being established in order to dissipate this waste energy into the environment. Furthermore, copper having a significantly positive temperature coefficient of resistance which can create a runaway effect, will aggravate this temperature rise in an unwound cable to a surprising degree. So much so that anecdotes about such wound up cables being turned into a welded mass of PVC and copper are quite common.

[tabbypurr]

induction doesn't happen to any significant extent, and if it did it wouldn 't cause heating. Why? Each bit of flex has currents flowing in equal and o pposite directions.

NT

[spuorgelgoog]

Unless you have pretty horrific Zs and parallel earth paths through the plumbing.

Owain

[PeterC]

I made a (very crude) reel for my 27m extension lead. I start rewinding by tucking the double socket into the centre, so it has to be fully unwound to use it. The highest load so far is under 1kW, so not much on 1.5 mil.

[Harry Bloomfield]

Malcolm Race has brought this to us :

Many do think the problem is inductive, but there is not induction because the flow in the live, is cancelled by that in the neutral. The problem is the resistive heating. The cable warms up because of resistance, the close coiling limits the ability to dissipate the heat and the cable melts.

[The Natural Philosopher]

+1.

Its hard to see what could in fact be heated 'by induction'

Not as though the reels are made of magnetic material...

[Bertie Doe]

Despite the obvious risks, the bath is becoming more attractive. Use of the shower is not a problem as showering's take place pre 9am and post 9pm.

My last kitchen brew had spillage issues and the tops of the walls were soaking. Inadequate extractor fan and a small window is the main culprit. The bathroom has a ceiling mounted Velux window and a powerful extractor.