Discussion > Staying safe - and powered!
Make sure you have at least one phone (obtainable at car boot sales) that works without mains electricity.
Martin A
An excellent point Martin. It's not just the lack of electricity that people need to have alternatives for.
Dave_G
It's all well and good getting a generator, but how is it wired into the house mains? How can you be sure that any incorporated "modified sinewave inverters" (whatever that might mean) will be compatible with your electronics?
Radical Rodent
It's all well and good getting a generator, but how is it wired into the house mains?
You need an isolation switch to take you off grid, you do not want to kill electricity line workers with your Genny or UPS. You can isolate the house completely or just take the section you want to power eg the central heating. You could have the central heating all fed through a 13 amp plug and just move the plug from a house socket to the genny or UPS 240V socket as a simple way to achieve this.
Breath of Fresh Air
You need an isolation switch to take you off grid,
And it needs to have some sort of automatic interlocking - so that, no matter what you do, the house cannot be connected to the generator until the house has been isolated from the mains, functioning or not.
You cannot count on yourself or others following the correct procedure (perhaps in the dark, possibly in a state of confusion or alarm).
Martin A
And it needs to have some sort of automatic interlocking - so that, no matter what you do, the house cannot be connected to the generator until the house has been isolated from the mains, functioning or not.
My switch is between the incoming main and the meter, it is a rotary switch with 3 positions, mains, no power and generator. You cannot get from generator to mains without passing no power and it passed the Electricity boards inspection .
My suggestion on the 13amp plug and socket is also foolproof if wired correctly.
Breath of Fresh Air
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Martin A
Connection of a generator to your own house electricity supply (the consumer unit) is best left to qualified engineers. No need to point out the potential dangers of getting this wrong!
Please also ensure that your generator has a RCD (residual current device) on the output. It could save your life.
For the most part I suggest that generator use would be limited to running the output to a multi-way extension to connect things as-and-when needed.
Dave_G
I am taking the liberty of copying a couple of useful posts which were originally on the thread about Belgian power problems.
Some practical ways to prepare for blackouts in the home this winter
With the likely prospect of power cuts lasting several hours or even days this winter there are things to watch out for and ways to be ready for them.
If you are heated by gas or oil remember a power cut prevents your boiler from working. They need electricity to run ignition, electronics, pumps and valves. The same is true of most gas cookers. So you will need off-grid power.
If you are totally electric then, sadly, there are limited options. It would be sensible to have a camping gas stove (£20-£30), a bottled gas room heater (£130, eg Rhino H02233 Catalytic Heater) and plenty of LED lamps and torches with spare batteries.
A. If you have a garden and/or a garage,
a petrol generator is the best choice. It can supply a constant 1000w for as long as you have the petrol.
1000w generators (‘inverter’ type which give smooth ‘sine wave’ AC enabling delicate equipment like computers to run safely) are around £250 - £300, such as:
Clarke-ig1000 (made in China)
You can, of course, buy as big a generator as you have room for, but the cost increases proportionally! So I’m using a basic 1000w setup as my example.
You could organise a shared setup with neighbours.
A generator will need basic shelter from the elements, such as an open garage or a simple ‘doghouse’ which allows a free Ÿow of air to ensure the unit doesn’t overheat and the exhaust is fully open to the air.
Important note. DO NOT run the generator in a closed garage or other enclosed space as the accumulation of exhaust fumes is deadly!
Although automatic switchgear systems are available to trip out mains and trip in generators, they are relatively expensive and also require more expensive generators (with electric starters).
B. If not,
then batteries and inverter are the better choice. A 1000w 12v inverter (£110) + large 12v 120Ah Lead Acid battery (£110) + auto mains charger (£30). These can be kept inside.
This setup has limitations on how long it can run for. It depends on the capacity of the charged battery. For example a 120Ah 12v battery will deliver 1000w for about one hour, 500w for about two hours etc. If you have extra batteries (which are around £110 each) then the setup can last proportionally longer before recharging.
Both systems will run the boiler, fridge, some lighting, FS TV and computer (NOT a laser printer though).
If you have all electric cooking, then purchasing a gas camping stove and a kettle would be strongly advised. They cost around £20-£30 for a double ring.
How to use either system when mains power goes off
1. Make sure all but your boiler circuit is turned off - lights, heaters, cookers, kettles, fridges, washing machines (dish and clothes) etc... (You don’t want to present your back up power supply with too much load when turned on).
2. Turn off your mains supply at the Fuse box (your property is now fully isolated from the mains grid).
3. With the generator or inverter OFF, connect it via a lead made up of two 13amp plugs and a length of 3 core 13 amp Ÿex that reaches from the generator to any 13A socket in the garage, garden or home.
4. Then start up the generator or switch on the inverter and all of your house circuits will be available - lights, mains sockets etc.
As you are limited to 1000w of power be very careful what you turn on.
Here are some power ratings which may be helpful:
Average gas/oil boiler - 250w - pump, valves and ignition etc.
Low energy light bulbs: variable ~ 20w. Even if you don’t like them it is as well to use them during power cuts. LEDs are better than CFs.
Fridge 200-300w, Freezers ditto.
TV ~100w + boxes, about 20w each.
Computer plus extras 200w variable, inkjets are OK but NOT Laser printers.
Home powered telephone units ie wireless type 3-4w.
Mobile phone chargers 10-20w max
THESE ARE FOR GUIDANCE ONLY
check your devices for power use.
If rating is not given in watt then multiply voltage times ampage.
V × I = W
Under no circumstances can you use:
Electric shower, electric cooker, electric kettle, dishwasher, washing machine, hoover, tumble drier, electric heater, iron, hair drier, microwave. Overloading will automatically cause the generator or inverter to cut out.
The National Grid should be able to tell you how long a power cut is likely to last - unless it is caused by storm damage. You can arrange to be rung back by National Grid to tell/text you when power has been restored - look up in Telephone Directory - or you can check with neighbours!
When you know power has been restored:
1. Turn off and totally disconnect your generator or inverter (unplug at both ends).
2. Turn on the mains at the Fuse box.
If you feel uncertain about how to do this, talk it over unofžcially with a friendly electrician or friend with electrical knowledge. Though the suggested arrangements are quite safe when used correctly, they might not get ofžcial H&S approval - but then not dying of hypothermia could perhaps be more important!
Sep 28, 2014 at 7:23 PM | Unregistered CommenterPhilip Foster
Although car batteries will work for a while, the correct lead acid battery is one purpose made and the camper/caravan batteries are very close to the ideal and some are the same. These batteries are designed to provide their rated output for longer, whereas a car battery is designed to give high starter output for a shorter period. An e-mail to Exide will get the information. Batteries can be charged by the mains when on and used during blackouts without a generator. Its a much cheaper option with an inverter. But if the blackout is protracted, a generator will be needed. Also if money permits a small diesel generator is cheaper to run on rebated No 2 diesel fuel, runs smoother and quieter and cooler. Water cooled versions are quieter and cooler running and if the oil is changed they last a long time. Stay away from 2 stroke petrol engines using any fuel, they are hard to start and give less efficiency, always buy a 4 stroke.
Sep 30, 2014 at 9:40 AM | Unregistered CommenterVal Martin
mikeh
3. With the generator or inverter OFF, connect it via a lead made up of two 13amp plugs and a length of 3 core 13 amp Ÿex that reaches from the generator to any 13A socket in the garage, garden or home.
Sounds potentially lethal.
Martin A
I had a rotary switch installed by an electrician that has three settings to control electrical power coming into my house wiring: one is to the mains supply, one in the middle which is to nothing, and one which is to an external socket on an outside wall. My generator is connected to that socket. Using the switch makes it impossible for me to connect my generator into the electrical grid by accident or oversight. I don't have the cost of this work since it was part and parcel of a much bigger renovation, but it did not take long to do, and the material costs were about £100 for switch, socket, and a bit of heavy cable.
John Shade
John - so do I infer your generator has a cable with a 13A plug at the end, its exposed pins carrying 230V, which you plug into the female socket on the outside wall?
If my inference is correct, it sounds as potentially lethal as the arrangement quoted by mikeh.
Martin A
Martin A, you do me wrong. The cable from the generator is buried, and is linked all the time to the female socket. This socket is not an ordinary 13A one, rather it is an external socket designed to handle at least 30A. A passerby would have to really go out of their way to undergo a lethal experience with this set-up.
John Shade
John Shade - sorry about that. I had misunderstood what you wrote. It sounded to me as if your house were connected to the outside socket, rather than the generator. Though I still can't quite visualise how the current gets from the outside socket to the house wiring without the use of a plug that, potentially, has exposed live pins.
But reassuring to know you do no not "...connect it via a lead made up of two 13amp plugs and a length of 3 core 13 amp Ÿex (flex?) that reaches from the generator to any 13A socket in the garage, garden or home" as mikeh repeated.
Martin A
Here is picture of a switch very similar to my one: http://www.mjselectricalsupplies.com.au/change-over-switches.
Power can now come into my house in two ways. Through a hole in the wall connecting it to the mains i.e. the grid, or through another hole in the wall connecting it to my generator. The switch allows me to choose which one I use. It is important to note, for the safety of maintenance work on the grid, that the switch does not allow my generator ever to be connected to the grid.
John Shade
Yes, those look big beefy switches, and ideal for the job. (Curious that the 20A, 25A and 32A switches cost the same as each other. Don't see why anybody would buy one of the lower rated switches when they could have a 32 amp-er at the same price.)
Still not sure what role the outside socket plays but it's clear that you have a robust and foolproof system.
Martin A
Keep the system you decide on as simple as possible.
I'd recommend running any generator output to a simple 4- or 6-way 13A distribution block and running lamps, TV, laptop etc directly from it. As already mentioned connecting ANY generating device directly to your home circuitry is fraught with potentially fatal consequences.
FWIW I am a 'competent' person (17th edition and various electrical/electronics-related qualifications) and have installed an ex-PC UPS device (connected to a pair of 180Ahr 12V batteries) directly to my consumer unit via a change-over switch that isolates selective circuits (lounge and bedroom sockets and lighting circuits only) and powers them via the UPS output. Plans to make this fully automated are being considered.
Externally I have a small (850W) petrol generator to use with our garage-based chest freezer although this only requires 'topping up' for an hour or so once a day providing we don't open/close the lid too often!
If you intend purchasing a petrol generator then get one adequately rated for your ESSENTIAL services PLUS a 50% margin i.e. tot up your power requirements by adding up the individual systems wattages. Lighting, TV, laptop and water heater (electronic ignition) total only 300W in my household but we have a small place, 500 to 1000W would cover most peoples essential requirements even if you consider the gogglebox to be 'essential'. If you get to 1000W then consider a 1.5kW generator.
Try to avoid the 2-stroke engine generators as mixing the fuel incorrectly can make it impossible to start OR cause it to sieze and it's an easy mistake to make. Four-stroke engine-driven generators use straight unleaded petrol. Also note that there is a legal limit to the amount of fuel you can keep on the premises and that it MUST be kept in properly certified-for-use containers.
One other advantage of 4-stroke petrol generators is that you can purchase LPG converters for them and even purchase a generator already converted for such - they are somewhat more expensive but LPG is easier to store and cheaper (in the long run). If you're not particularly fit or suffering weakness from health effects then also consider electric-start generators as most small-output units are PULL start and can take some considerable effort to get going.
Inverters should NOT be of the 'modified sinewave' version as they can cause damage to modern electronics, particularly PCs and TVs. Pure sinewave devices are more expensive but common sense under the circumstances.
If the thought of messing with engines, inverters and household wiring deters you then stay simple and use JUST batteries. A standard 12V car battery can power LED lights, your wi-fi modem and laptop (via adapters if necessary - depends on your equipment model) giving you basic lighting and entertainment - keeping yourself entertained during power cuts becomes quite a task if it lasts more than a few hours and decent lighting to read/work by makes a HUGE difference (try going three or more days without power/decent lighting.....hence my own adaptations to power requirements).
Above all, don't try to do something you aren't 100% certain (or qualified) to do. It will only lead to frustration as a minimum and life-threatening outcomes at a maximum.
Dave_G
There are justifiable concerns for the security of our mains electricity supplies and various suggestions in numerous comment threads of methods to circumvent them.
I'm starting this thread as a place to collect ideas that people could use or adapt to their own particular circumstances on the understanding that it's better to be prepared than to be caught short.
Buying a generator may be a simple one-stop solution but many people may not know which type, the power output, the expected running times, the running costs (probably irrelevant under the circumstances) etc. So perhaps someone with experience can offer a self-help guide?
For the more adept there are batteries/inverters and warnings have already been posted about using 'modified sinewave' inverters due to their 'distorted' output not being very kind to sensitive electronics i.e. running your PC or house heating timer from one could, potentially, ruin it. Can anyone offer some advice on makes, models, power output etc to clarify this area?
I myself have my own variagated solutions from woodstove to modified UPS devices (powered from externally mounted deep discharge leisure batteries and charged via the domestic E7 circuit to lower running costs).
Even simple advice such as LED lanterns (particular makes/models) could make a difference to someones life in a power cut.
So, anyone with practical advice, experience in particular systems or even just ideas to make life under candlelight a bit more sufferable, please put your ideas forward. They will all be useful, I'm sure.