Loosing 17KW

then probably only when the house has little heat demand.

I don't know your background or competence but as a qualified electrician I feel I must warn you that no domestic supply is rated at 100kW, you'll need a 3 phase industrial supply of at least 150A per phase. You'll also need a serious cable to carry that lot 200 feet, at least 70mm2

Greg.

No. I finally have it. It IS the Bromley Kipper Factory!!

BTW, is this thread about losing 17 kW, or loose-ing it on the unwary?

He's actually achieving this by using a large bank of ni-cad rechargeable battery's left over from the B&Q winter sale and Ower Gert [ bless her heart ] has agreed to loan him the stays out her corset as cables. These should have a safety factor of 101% or they did have when Mother out Law used them to launch the last batch of V2's on Billingsgate.

-- Regards,

John Stevenson Nottingham, England.

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A worthy warning - Andrew *might* not be registered but is certainly qualified to mess about like this.

It still annoys me that in a previous life I designed the electrical heat treatment system for part of Dounreay but I'm now alledgedly insuffciently skilled to fit a 13amp socket.

Charles

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Greg,

I have to differ - a domestic supply blows it's fuse at 100Amp @ 240v ie 24KVA

Don't worry - the gen set is 12 foot away from it's load and the cable is already to hand and capable of mooring the QE2 in a force 9 gale, though I do confess to using 125amp sugs and plockets (thanks Peter) at a max load of 150amp for short periods.

AWEM

Well I certanly hope so, otherwise you're going to be a very unpopular neighbour and possibly have the authorities down on you. RF screening depends very much on the installation, the last place I worked had neighbours with an induction welder a lot less powerfull than the one you have, and the interference was enough to get the authorities involved. They had serious problems with getting adequate earthing.

Be very wary of generator ratings, they are notorious in the industry. It may be rated at 100kVA but that is most likely at 0.8 power factor so the engine will only provide 80kW, and that's flogging it to death. It's usual to run a set at rather less than it's maximum.

Greg

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Interesting point here Charles (and thanks for your confidence you misguided innocent!) - this is totally isolated from the public supply - but I suppose you could call it a 'portable appliance' in the braodest sense of the words.

Dounreay eh - I was at one time responsible for the Ferranti Argus real time monitoring computers of that fizzing pile, as well as Chapel Cross, and Dungeness 'B' - small world.

AWEM

Well I just thought it worth pointing out, there are a lot of people out there who are a danger to themselves as well as others 8-)

I was in the same boat, not even allowed to do any work on my tenanted properties, and a lot of experienced electricians have found themselves the wrong side of the law too. So I went to night school and got qualified, not hard, in fact quite revealing and satisfying.

And do you know the funny thing?, I bet you couldn't fit a 13A socket to current regs 8-), I know I couldn't before the courses, the fact is that the regs are changing so fast that you do need ongoing training to keep up.

Greg

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Greg,

No I think this one is probably under rated although I agree pf comes into the equation (have you ever tried to predict the power factor of a three phase, phase controlled SCR rectifier which is what the genny 'sees' as a load)

The engine is a 6 litre turbocharged diesel which in other applications is rated a 220 hp ( ie capable of 163.46KW) at the 1500 rpm we are running at. (and you should see the fuel level fall !)

AWEM

Aaahhh different screws ? Damn cunning these beurokrauts.

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

Which is rather less than 100kW, so in what way are you differing?

But leaving that asside, many domestic supplies have a 63A fuse, others 80A, and a few 100A. Also many that were originally 80A or 100A get dropped a step whenever they refit a fuse for any reason, simply because they found that a lot of the old fuse holders melted before the original fuse 8-). Oh and the nominal supply voltage in this country has been 230V for quite a while now, although many still receive 240V as it is within the +10% tolerance. New estates, which usually have new sub stations tapped to 230V, are typically supplied with 63A 230V TNC-S supply.

The sum total of this lot is that many domestic supplies are less than

Greg

Well I might have guessed that there would be one or two other process control types out there in the group...I cut my programming teeth writing process control software on PDP 8's and PDP 11's - we avoided the nuclear industry, mostly petrochemicals..and yes, the company I worked for at the time did supply a monitoring system for "that" pipeline that runs through Buncefield...

Regards, Tony

No I've never had to predict it, much easier to measure it!. I used to design such things and they are actually very common loads for generators in the form of large battery chargers for UPS systems. They are also a PITA for generator controls which I design now, because of the voltage harmonics they produce confusing the instrumentation systems.

I just thought I should point it out because a lot of people fall into the trap of thinking that you can get 100kW from a 100kVA generator, including a lot of our customers 8-(.

Greg

Well no actually a bit more significant than that, things like what heights are permitted in different locations, what protective devices are needed depending on the location, what mechanical protection the cables need, when spurs are permitted, the maximum size of rings, what has to be different in an office full of PCs, the loop impedances that are permitted depending on the location and type of supply. There is a big list of issues to be considered when 'simply' fitting a socket, and if you get them wrong you could be prosecuted if there is an accident.

And here's one to ponder, it is very likely that part of the requirement for the new buyers pack that is to be introduced soon is that you must have a current periodic inspection certificate. As a qualified inspector I can tell you that very few houses that have had DIYers working on them will pass such an inspection without rework, often quite extensive, so those cheap DIY jobs are going to turn out to be anything but cheap the next time you try to sell your house!.

Greg

Greg, the way I read it the load is 200' away from the house but not connected to the house electricity supply. There is a 100kVA generator

I think...

Yes that's what I understand too, I just can't see why my statement that a domestic supply can't handle 100kVA is contradicted by a calculation that it can only supply 24kVA !!!! 8-)

Greg

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Absolutely correct Duncan - perhaps I could use a few of your amplifiers to drive it

AWEM