Generator connection to house
- Thread starter jimAuk
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Ooops..
but digging self out of hole..
you could feed your "essentials CU" off a suitably rated MCB in your other CU, your switch would have to be rated >= supplying MCB rating
Phew,,, out of hole now!!
but digging self out of hole..
you could feed your "essentials CU" off a suitably rated MCB in your other CU, your switch would have to be rated >= supplying MCB rating
Phew,,, out of hole now!!
How will you know the mains is back on?
Thats a good question!!!!!!!
Look out the window (if at night ) and see if neighbours lights are on?
Or fit a light on the grid side that will light when back on??????
Ideas please!
How will you know the mains is back on?
Thats a good question!!!!!!!
Look out the window (if at night ) and see if neighbours lights are on?
Or fit a light on the grid side that will light when back on??????
Ideas please!
MCB - doorbell TX - doorbell (proper bell type) - all fitted to main CU
that'd let you know!!
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It stands for Terra-Terra (though don't ask why).
Basically it's doing as Spark123 suggests - you put an earth stake into the ground and that's what you'll be relying upon as your earth when using the generator. You'll need an RCD as this earth isn't as 'good' as taking one from the DNO.
Distribution Network Operator. Basically yes, your electricity company (though not necessarily the one that sends you your bill).jimAuk said:
Yes I do know that bit, Tescos have not quite taken over everything, LOL
Thanks all it has made things clear (?)
Need 100- 125 Amp switch
3 pole (break before make, with off position) Need best price/make
Need dedicated earth with RCD in
Isolate key ciccuits, lights, bolier and sockets
And bell so I know when to turn the generator off!
Katko were the best price when I did a job that needed one.. that was a couple of years ago though..
In all honesty you'd be better off feeding your essentials CU as a submain from your main CU.. this will allow you to use a smaller, cheaper switch
In all honesty you'd be better off feeding your essentials CU as a submain from your main CU.. this will allow you to use a smaller, cheaper switch
Just to clarify - 2 pole will suffice, as you don't need to switch the earth from your supplier, you just can't rely on it. Even if you did switch it, you'll probably be connected to it through your neighbours' water/gas supply if you've got copper/lead pipes coming in.
I'd choose a three position one, rather than direct changeover.
But I thought it was stated above that the switch would still need to be rated at 100A+?
Yes I understand. 2 pole as a dedicated earth will be used for the generator via spike.
Not if the supply to the "essentials CU" is fed off a 40A MCB in your main board...
but as your genny is only 21.5A COP then the demand off that board should be less than this.
but as your genny is only 21.5A COP then the demand off that board should be less than this.
But does not this set-up allow the genny to be turned on and feed power into the grid and vise versa? i.e there is no break before make switch?
Coming back to the Human factor?
Apart from that I see what you are saying.
Coming back to the Human factor?
Apart from that I see what you are saying.
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With non grid tie generation I have always considered one may need to change the generator therefore being able to plug in is an advantage. In theory over 16A needs a way to remove load other than unplugging but in practice there are normally isolators of some type already.
So easy method is to use a consumer unit for all items wanted to run on generator and to feed this with a plug and socket. From the existing consumer unit you have a socket and normally the new consumer unit is plugged into that socket.
When power fails you unplug and plug into generator instead.
This means you can use any generator with suitable socket.
As to size well we jump 16A, 32A, 63A and your generator can supply 32A so that would seem logical size. However it already has 16A sockets fitted. Using a duel feed to a consumer unit and two plugs may be better option and have two 16A sockets from existing consumer unit. That way you can have one half feeding lighting and central heating and other half feeding essential sockets TV, Freezer, Fridge etc.
There are of course 100's of ways to connect it all up. But as to break before make there can't be anything better than plug and socket.
I have a similar problem two 13A outlets with a 3KVA supply able to supply 6KVA for starting. In my case an inverter powered from 3 x 180AH batteries but main supply is only 16A however unlike you there is very little ability to connect to inverter other than through 13A sockets.
So either we split the consumer unit with two independent inputs or we limit to 13A likely the latter. We are only losing a couple of amps where you lose 16A with single connection.
However do you really need over 16A for essential services? And of course the less you draw the longer the fuel lasts. Maybe just lights, central heating, TV, and fridge/freezer is enough? and one single 16A socket and a consumer unit supplying just 16A is enough?
My problem is further complicated but my son getting a generator as well which is easy with plug and socket arrangement the same may apply to you with inverters and wind chargers and photo cells in future so I would recommend you consider plug and socket arrangement.
The points made about earths are valid and in my case it uses the steel hull of the narrow boat. In your case you will likely need earth rods. However with a TN-C-S system any earth rod becomes an extraneous-conductive-part so there is not reason why you can't fit earth rod as well as boards earth. Once you are running on generator the system becomes TN-S not TT but this is something for your electrician to worry about not you.
I like the Yanmar engine we had one of them on our safety boat 350HP into a water jet with a 16 foot boat made in aluminium it was quite a fast boat. Needed on river seven. However the capacitor voltage regulator is not so hot and you must expect quite a variation in voltage. Any florescent lamps need to be HF and any 50mm spots need to be SELV type. (With switch mode power supplies) I would expect 200 to 250 volt and of course anything used must be able to work with that variation. Anything with switch mode power supplies should be OK. So new LCD TV not a problem but old tube set may have problems.
Loads to think about I know but that was what you wanted. As to me now no longer active but working in Algeria and Falklands I had a lot to do with small generators. In UK when a bit larger with 400 and 650 Megawatt (Connah's Quay and Sizewell with short time at Longgarnet) so I have worked with both grid and non grid supplies.
There is no ideal answer and one has to consider what you have. I hope I have given you food for thought. At the end of the day you will talk with your electrician and work out what is your best option. It would help us all if once worked out you tell us what you did and how well it worked.
All best Eric
So easy method is to use a consumer unit for all items wanted to run on generator and to feed this with a plug and socket. From the existing consumer unit you have a socket and normally the new consumer unit is plugged into that socket.
When power fails you unplug and plug into generator instead.
This means you can use any generator with suitable socket.
As to size well we jump 16A, 32A, 63A and your generator can supply 32A so that would seem logical size. However it already has 16A sockets fitted. Using a duel feed to a consumer unit and two plugs may be better option and have two 16A sockets from existing consumer unit. That way you can have one half feeding lighting and central heating and other half feeding essential sockets TV, Freezer, Fridge etc.
There are of course 100's of ways to connect it all up. But as to break before make there can't be anything better than plug and socket.
I have a similar problem two 13A outlets with a 3KVA supply able to supply 6KVA for starting. In my case an inverter powered from 3 x 180AH batteries but main supply is only 16A however unlike you there is very little ability to connect to inverter other than through 13A sockets.
So either we split the consumer unit with two independent inputs or we limit to 13A likely the latter. We are only losing a couple of amps where you lose 16A with single connection.
However do you really need over 16A for essential services? And of course the less you draw the longer the fuel lasts. Maybe just lights, central heating, TV, and fridge/freezer is enough? and one single 16A socket and a consumer unit supplying just 16A is enough?
My problem is further complicated but my son getting a generator as well which is easy with plug and socket arrangement the same may apply to you with inverters and wind chargers and photo cells in future so I would recommend you consider plug and socket arrangement.
The points made about earths are valid and in my case it uses the steel hull of the narrow boat. In your case you will likely need earth rods. However with a TN-C-S system any earth rod becomes an extraneous-conductive-part so there is not reason why you can't fit earth rod as well as boards earth. Once you are running on generator the system becomes TN-S not TT but this is something for your electrician to worry about not you.
I like the Yanmar engine we had one of them on our safety boat 350HP into a water jet with a 16 foot boat made in aluminium it was quite a fast boat. Needed on river seven. However the capacitor voltage regulator is not so hot and you must expect quite a variation in voltage. Any florescent lamps need to be HF and any 50mm spots need to be SELV type. (With switch mode power supplies) I would expect 200 to 250 volt and of course anything used must be able to work with that variation. Anything with switch mode power supplies should be OK. So new LCD TV not a problem but old tube set may have problems.
Loads to think about I know but that was what you wanted. As to me now no longer active but working in Algeria and Falklands I had a lot to do with small generators. In UK when a bit larger with 400 and 650 Megawatt (Connah's Quay and Sizewell with short time at Longgarnet) so I have worked with both grid and non grid supplies.
There is no ideal answer and one has to consider what you have. I hope I have given you food for thought. At the end of the day you will talk with your electrician and work out what is your best option. It would help us all if once worked out you tell us what you did and how well it worked.
All best Eric
Thanks very much Eric, I will have to read and probably re-read and then get back to you with a few questions.
But one straight away, are you stating that although I only have 16A 240v sockets, because there are 2, by feeding both in gives 32A?
Or am I just looking at it to simplisticly?
I like the idea of the socket lead that is either pluged into grid or genny, like you said, simple and will not allow for error (?)
Thanks
But one straight away, are you stating that although I only have 16A 240v sockets, because there are 2, by feeding both in gives 32A?
Or am I just looking at it to simplisticly?
I like the idea of the socket lead that is either pluged into grid or genny, like you said, simple and will not allow for error (?)
Thanks
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One problem I see is to get 32A out of your generator you will need to modify it and fit a 32A socket. Or keeping two separate supplies of 16A. Either using two small consumer units or one with split inside you could arrange the circuits you want to supply into two each supplied but a 16A plug.
So if you remove the circuits which you want to power from generator from existing consumer unit and then connect them into new consumer unit which will be feed by two 16A plugs. Then on existing you fit two 16A sockets which you then simply plug the new consumer unit into.
When you have a power cut you simply unplug from mains sockets and plug into generator. At 16A there is no need for isolators. It also means you have not modified generator and any other generator can be plugged in the same way.
Also there will be delay in changing over. Remember fridge/freezer should not be re-supplied straight away. The pressure needs to drop before you re-supply or the overload in the fridge/freezer will keep trying to start and tripping and auto re-setting until pressure drops. Once power is lost you should wait 3 minutes before re-connecting. So having lights on one supply and fridge/freezer on another will allow you to power lights straight away and leave time before connecting fridge/freezer. You should also consider some emergency lighting. There are models designed for discharge lighting which remain lit for 5 minutes after power is returned because the discharge lights take so long to start up. This means when you swap sockets and re-power you are not plunged into darkness. I didn't use the delay type and I always forget and have to turn power off again to see the light switch.
My son has all 12 volt lighting so power on or off makes no difference to lights. Battery charger is always connected. A proper three stage charger.
So if you remove the circuits which you want to power from generator from existing consumer unit and then connect them into new consumer unit which will be feed by two 16A plugs. Then on existing you fit two 16A sockets which you then simply plug the new consumer unit into.
When you have a power cut you simply unplug from mains sockets and plug into generator. At 16A there is no need for isolators. It also means you have not modified generator and any other generator can be plugged in the same way.
Also there will be delay in changing over. Remember fridge/freezer should not be re-supplied straight away. The pressure needs to drop before you re-supply or the overload in the fridge/freezer will keep trying to start and tripping and auto re-setting until pressure drops. Once power is lost you should wait 3 minutes before re-connecting. So having lights on one supply and fridge/freezer on another will allow you to power lights straight away and leave time before connecting fridge/freezer. You should also consider some emergency lighting. There are models designed for discharge lighting which remain lit for 5 minutes after power is returned because the discharge lights take so long to start up. This means when you swap sockets and re-power you are not plunged into darkness. I didn't use the delay type and I always forget and have to turn power off again to see the light switch.
My son has all 12 volt lighting so power on or off makes no difference to lights. Battery charger is always connected. A proper three stage charger.
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