Wondering if anyone has had any experience with this...
As per normal, I have my grid power entering my house, this then goes through a 80A fuse that belongs to the electricity board, it then continues to my electricity meter, and then onto my consumer unit...
The thing is, I want to disconnect the tails that come from my meter, and connect them to a generator transfer switch - this then connects back to my consumer unit, and also to a generator.
The options I have are..
Do it live - not a clever idea, especially as my consumer unit has a metal back!
Pull the electricity boards fuse out, move it, and replace the fuse (minus the metal tag/seal)
Call the electricity board, and see what extortionate rate they will charge me..
I have however read about someone calling the electricity board up, and them saying, "just pull the fuse, ring us when you are done, and we will send someone out to check the installation, and replace the fuse and seal it up again"
I go with pulling the fuse and then having it sealed again. Job's done.
The thing that's getting me though, is the fact that your tapping in to the mains tails. Why ? Can't you take the bridge from the BUS bar side of the mains switch in the CU ? Doing it this way gives you at least some sort of isolation if you have to carry out any maintenance on the new system.
So do you think I just do it, and plead ignorance if the missing/broken seal is spotted or do I call the electricity company and ask them (slightly harder to subsequently plead ignorance after that!)
Another thing, is we had the meter changed about a year ago, so all the seals are new :-/
In my CU, the meter tails go directly into the main breaker, (there is no simple switch) and then two wire connect from this same point to the other lighting breaker.
On the other side of both breakers, there is a copper bar that feeds all the mcb's for both circuits - this way, if the main power breaker trips, we are not left in the dark Probably standard practice, but as I have never looked inside another split load box before, I can't comment!
I want my generator connected before both of these breakers, and to both circuits (so we can use the lights, and the sockets!)
I was actually going to purchase a 100A isolator, and connect the meter tails to this, then on to the transfer switch, for the reason you suggest ;-) ...and possible upgrade to an automatic system later.
Apparently some people have an electricity board provided isolator between their meter, and their CU - I am not that lucky :-s
Woa up there horsey !!! A generator doesn't have neutral potential on it. Both connections become live feeds and if it is to take over supplying the house in the event of a power cut, then you'll need to upgrade the earthing and take only a single phase from the genny, to feed the house.
It works by making the grounding spike in to your neutral potential. Very dangerous if not done properly. Not to mention the fact that, if the mains supply then comes back on while the genny is running, then it could blow every fuse you have in the house and may even trip out at the local sub station if it is a large capacity generator.
I originally thought that you had automatic change over, to bring the genny online when the mains failed. But you say "possible upgrade to an automatic system later". That's a big NO NO !!!!!
FYI A proper automatic transfer switch makes it impossible for both grid and generator feed to get connected together!
Generally speaking, with a non synchronised genset, the grid fails, so the ATS disconnects all power to the house, starts the generator, waits for the generator to stabilise, then switched the house from nothing, to generator power If the grid is then restored, it will wait a bit, to make sure the grid is staying on, then it disconnects the house, waits a bit, then switches over to the grid (If the grid and genset are not synced then switching directly would be messy!)
It then keeps the generator running for a bit, then finally shuts it off
I understand where you are coming from, as I wouldn't want to try to supply power to my whole road! or kill someone working on the street wiring by back feeding (I presume a step-down transformer would work in reverse, ramping my
You could use a step down tranni' as a supressed earth to give a decent neutral potential to supply the house circuits, and reduce the fuel consumption of the generator into the bargain, using the transformer looped from phase to primary winding, then on to the secondary winding and out to earth. But as I say, both connections on an AC genny are phase, so it literally doesn't have a neutral and is dangerous if used with capacitative loads.
You could ruin your tele' or damage any IF filters in other appliances if they rely on a phase to neutral supply, so it then becomes a very expensive installation if you have replace everything. The grid itself is literally phase and earth connections, but an AC generator is alternating phase / phase supply.
I had no seal on my fuse for years and no meter reader ever noticed or bothered to comment on it. A month ago I had my meter replaced, and to save any questions I made up my own seal - stripped the plastic off a thin piece of multi-strand elec wire and attached it with a piece cut off an crimp. It looked reasonable enough, but even if it didn't and anybody had said anything I wouldn't have cared too much. After all, what are they likely to do? Take you to court for cutting off a company seal?
When I moved in to my current house, there wasn't a seal on the main fuse either; I asked the lecky company to check it over just in case the previous owners had been fiddling the meter. They (eventually) sent someone round, and just fitted a new seal, they didn't give a ... about checking the meter.
Fit a dp isolator with an insulated case! I would advise takeing a look at the 16th Ed of the wireing regs, there is a whole chapter about private generation. You may also want to advise the supply company so they are awere.
Contact your local electricity company and ask them to fit an isolator - simple :-)
I say local electricity company, but depending on how anal they want to get, the request *may* need to come from your supplier (the ones you pay your bill to) which may be a different company.
If you need to go via your supplier, the request will be sent via a back- end computer system called the Data Transfer Network (DTN), will be known as a "flow", and will probably end up with their metering department - it`s a simple job, usually free of charge.
I have a "power conditioner" rated at 40A - this contains a bloody great transformer (it must weigh about 50KG!)
It is not a step-down transformer, as the generator's output is the voltage I require!
Excuse my ignorance, but how is a petrol generator different to the output of the grid? I was under the impression the grid's Neutral was connected to earth, so they only need to run live cables - this being the reason people got electrocuted - they touch the live, and this shorts to earth, or neutral!
We install isolation transformers in bathrooms, and on building sites, so the neutral is no longer connected to earth, making electrocution impossible unless you touch both live and neutral together - surely a generator is safer then the grid, due to the neutral/earth isolation?
Please correct me if I am wrong, it is just how it seems to work from my point of view!
You're right about the grid supply being phase and neutral, but a generator supply is phase / phase with no earth / neutral potential. This means that any appliances you have in the house may not be switched off when you think they are and may actually continue to heat even if you think they are switched off.
Do this simple test with a meter.
Set your meter to the appropriate setting to take the AC Voltage of your supply.
Place one test probe on the earth connection of your mains supply and the other probe on the neutral connection. You should see that the test meter doesn't show any or shows very, very little voltage flow. If anything does show, then it more than likely it has no current large enough to run anything other than a small torch bulb and would dissappear if any large load were connected across them.
Now, keeping one probe on the earth terminal, place the other probe on the live connection. Your meter should now be showing the full supply voltage of your system and it will carry a very large current potential. This allows you to run all your appliances.
Next, go and start up your generator and carry out the same tests as above. You should see that both, what are known as live and neutral, are showing half of the rated voltage to earth, that it is said to supply. This is because an AC generator works on the principle of each phase being 180 degrees out of phase with the other, therefore, it supplies + phase on one side and - phase on the other, and the phases alternate between supplying + and - of the supply at the rated hertz frequency of the generator.
There is no neutral / earth potential from a generator and it must be properly connected to the AC supply system, when and if the load has any capacitative loads, i.e. televisions, IF filters in appliances, etc. etc. Please be careful if you intend to use a generator as a backup supply for your domestic system.
An isolation transfomer only works by bringing in different tapps on a transfomer to supply an increasing current load. It is nothing fancy and sure won't help in the situation of supplying a domestic AC electrical supply.
I watched the man change my electricity meter. When he took the fuse out he put a plastic blanking plug in the live end of the fuse receptacle. I'd have given a leg to have had one of those when I last had my fuse out. There's something about a little shiny piece of metal that can fry you in a heartbeat. anyway, he also took out the neutral as well, if that's worthwhile knowing.
On the question of generators being used when mains failures occur, these obviously aren't used indoors. No problem in a rural area, but isn't noise a possible problem in built-up areas?
I'm assuming the genny would be running during evening/night time hours.
I have put my generator in a box, with air forced through the box for cooling (Large fan unit mounted on the side of the box) - This has reduced the noise considerably.
Also, where I have located the generator, it is shielded from almost all sides, so the noise mainly goes upwards
If I run the generator at night, then walk across the road to my neighbours house, you can only just hear it running.
If I go next door, then you cant hear it at all.
So it doesn't piss the neighbours off! (Plus, if there is a power cut, they know they can watch TV at my house!)
Ok, did the tests, and as I expected, you were right!
The next question, what can I do about this? - My generator seems to satisfy all four of my UPS' A small standby a larger Line interactive and two online large units (35KG jobbies!)
How would I run things like TV's etc. from the generator without risking causing them damage?
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