Emergency generator question

[PoP]

Cue 1970's.....Arthur Scargill is around someplace.

PoP

[PoP]

Shirley better to consider heating water in the microwave during an outage isn't it? Can't remember the power consumption of a microwave but I thought it was relatively small compared with a kettle.

PoP

[The Natural Philosopher]

An emergency bodge is to use a nasty 'live plug' wired in backwards to your ring main, and use th consumer unit to select which circuits are activated. DO switch the main circuit breaker off tho. Your generator is not equipped to feed the national grid if power is restored ...or the neighbours lights if it isn't :-)

NOTE: This is thoroughly bad practice, probably illegal, and extremely dangerous if you don't understand what I said.

However, it may prove useful in an emergency.

[Dave Liquorice]

3 normally, power cuts here are either measured in less than a minute or 6hrs+.

Who *needs* TV, there are such things as books, cards, board games etc.

And their "Use by:" date is?

Thats the one you really need to take care of. Get a small Camping Gaz stove. Think I've seen 2 packs, stove and lantern for about =A320. Take =

care with these they do get hot(doh!), have naked flames and can present a fire hazard.

But will they be open if their till doesn't work or have poor lighting. Think of H&S and great vats of hot fat in poor lighting, if an employee had an accident or a customer come to that the chippie would be liable...

Things have changed since the dark days of the 4 day week. I can remember going shopping in places in virtual darkness then and of course cashiers could add up and work out chnage without the aid of a machine...

[The Natural Philosopher]

Sopld fuel stoves and open fires and candles all work well for me. Kettle boils on the aga, but I have used camping stoves as well. AND barbecues.

[Wanderer]

If you decide to go down that line, wire it in permanently. Somewhere along the line *someone* will decide to try and use a lead with two plug tops back to back to feed into a ring main, and that's lethal.

Generators must have their neutral separately earthed, unless the incoming supply is pme, when you are allowed to bond the earth of the generator to the earth terminal at the meter position. Don't neglect to make proper provision for protection against overcurrent and earth leakage faults. Most users of stand by generators don't give a second thought as to whether or not they are using a safe arrangement, in fact I'd go so far as to say that most generators are used in a positively unsafe manner when used as an emergency domestic supply.

You will need a two pole break before make changeover switch, so that the generator cannot run in parallel with the main supply. Your local distribution company will advise on the current requirements for using a stand-by generator.

[The Natural Philosopher]

But power cuts here are rare and short-lived, usually related to aged

Not round here they aren't. Usually related o large trees falling across overhad lines. Usually takes a minimum of a coule of hours to clear, if its just isolate/remove/switch on, or up to several days if lines are actually broken in several places.

[Andrew Gabriel]

There are rules relating to UPS's and generator sets. Earthing them properly is a rather non-trivial task. You aren't allowed to assume an earth provided by your electricity supplier is still working when the supply fails.

[Andrew Gabriel]

I don't think the magnetrons in domestic microwaves ever exceed

50% efficiency. The waste heat is blown through the food compartment too, but I doubt much actually goes into the food/water -- it's mostly wasted.

[Andrew Gabriel]

If you want to go this route, you must have much better interlocks to ensure there's no way you can feed electricity back out of your supply and electrocute someone working on the supply line. This is normally done with a transfer switch.

Also, some circuit breakers may not be designed to stay live on the load side when switched off.

[Simon Gardner]

I seem to recall that one question raised when I last lookled into this in

1999 was the quality of supply delivered by the generator.

One sort was fine for lighting and heating pumps etc. But a very much more expensive standard of generator was needed safely to power satellite receivers, computers, TVs and such like.

Anyone throw any light on this one?

As an aside, I am always surprised to see people in this newsgroup keen to disable their ability (blocking off, using the chimney for something else etc) to burn wood and coal in an open fire. That's always been our standby in case of power failure in January and I'd be reluctant to buy a house without a functional chimney.

[We also have an electrolux camping freezer that will run inter alia off bottled gas and a considerably older camping gaz stove bought during the 3-day week and still going strong.]

[Colin Blackburn]

I'm already there. Off the grid with two wind turbines, batteries, inverters and three (the previous occupant did nothing by half) diesel generators---should the wind fail, coal/wood fire with back boiler providing non-pumped heating to bedroom radiators, oil and lpg cooking, and some oil heating (CH and stove). And, plenty of fuel stocks for the winter.

Colin

[Dave Liquorice]

Just looked at the rating panel on our fairly recent Category E (800W output) microwave. Input power is 1.24kW so over a 1/3rd of the input power goes has waste heat.

Kettles must be far better or they would melt, not having forced cooling... Then of course you have the losses in an invertor and the size of the battery required to store that amount of energy. Kettle of a gene is probably OK provided you don't overload the gene.

[Dave Liquorice]

Even if I pull out the main fuse and switch off the breaker I still assume that everything is live until tested with a volt stick and even then I check cautiously on first contact with tools/me.

If there are maintained circuits all the CU(s) should be labled with a warning and each maintained outlet/fitting as well.

[Nick Finnigan]

They have water cooling though, and a fair heat capacity.

Method: Cool kettle using several litres of tap water, measure

1 tea-cup of tap water into kettle, and time until bubbling Cool kettle using several litres of tap water, measure 2 tea-cups of tap water into kettle, and time until bubbling

Results: 60s and 90s.

Conclusion: a microwave is just about as efficient for one cup of tea, but slower.

[PoP]

The issue might be that it isn't you doing the work. It is very dangerous constructing a potentially lethal installation which depends significantly on being used and maintained by only one person, that person having specialised knowledge.

What about if your house catches fire and the fire brigade have to break in to deal with the situation? They would presumably try to remove power from the building as part of their duty.

Also, as we've seen only too well in the recent past, you have a duty of care for your armed burglars and could get sent to prison if you dare put them in any danger ;)

Good plan. I was under the impression that UPS outlets were supposed to be labelled appropriately anyway?

PoP

[Owain]

"Dave Liquorice" wrote Owain wrote: |> My main difficulty is the tv. |Who *needs* TV, there are such things as books, cards, board games etc.

I don't enjoy or even have cards or board games, and reading is difficult in insufficient light. The tv is a difficulty because the reception is outside my control.

|> I have a battery radio and tv (and a box of 20 D batteries I got |> cheap from government surplus) |And their "Use by:" date is?

Well, I bought them in case bad things happened with the Millennium Bug :-) But they still have electric in them because I have two torches running on the same batch.

|> I am also dependent on electric for cooking. |Thats the one you really need to take care of. Get a small Camping Gaz |stove.

Requires gas cylinder storage which isn't allowed in my flat. If the chippie isn't open I guess I have to go to bed hungry :-( Unless I can beg off a gas-cooker equipped neighbour.

Owain

[Colin Blackburn]

What exactly isn't allowed? I guess they don't allow lpg cylinders but do they specify the small camping cylinders, Gaz, Coleman etc? You could get a Trangia, meths stove, or a multifuel stove, take a look at Primus, if your lease does excludes *all* gas cylinders. Just having the ability to boil a kettle for two or three days is useful.

Colin

[Simon Avery]

Hello Andrew

I bet they were glad when granny's kettle finally boiled.

[Dave Liquorice]

I'd be surprised if camping gaz type gas clinders are excluded but it does depend on the extact wording of the lease though. I should imagine it's designed to stop the storeage of red/blue propane/butane cylinders it may catch all compressed gas though. Wonder how they deal with gas cigarette lighters?

Agreed, which is worse a container of compressed gas, a container of refined petrol (Coleman fuel is basically petrol), a container of meths or a couple of boxes metahaldyed(sp!) solid fuel (not that you'd want to use that inside it does pong a bit).

Almost essential, a hot drink, washing etc.