Switching in a generator
Discussion
We have had a number of sometimes lengthy power cuts and we have oil heating so lose everythung when the leccy goes. The other day it was 7 hours and we have my 90 year old father in law living here.
I have ordered a 3kw genertor.and I am intending to have a switch installed in the plant room that allows me to switch out the mains and switch in the generator to give us basic electricty around the house. I will locate the genertor ourside and then have a socket installed in the putside wall running the 2m to the plant room inside.
Ball park of how much an electrician may charge to fit that outdoor socket and switchgear?
I have ordered a 3kw genertor.and I am intending to have a switch installed in the plant room that allows me to switch out the mains and switch in the generator to give us basic electricty around the house. I will locate the genertor ourside and then have a socket installed in the putside wall running the 2m to the plant room inside.
Ball park of how much an electrician may charge to fit that outdoor socket and switchgear?
3kW will be marginal to be useful I would think Personally I'd be looking at 5-6kW (Not KVA) useable)
The startup current of thing like motors can be substantially more than run current for a lot of devices.
A lot of the low end generators have power figures that are more Hans Christian Anderson than fact.
The startup current of thing like motors can be substantially more than run current for a lot of devices.
A lot of the low end generators have power figures that are more Hans Christian Anderson than fact.
You'll need a manual changeover switch. But You'll also need to ensure you have an earth independent of your grid supply. An electrician will identify and resolve this.
3kw gen, needs to be Pure Sine Wave, will run a boiler and a few low-power items like a fridge and freezer (more challenging if you have a big chest freezer). In a power cut You'll want to switch most things off before starting the generator, manually switching to generator and then switching a few items back on.
It won't run a standard kettle or anything electrical heating.
There are battery systems with gateways that provide an uninterrupted power supply.
3kw gen, needs to be Pure Sine Wave, will run a boiler and a few low-power items like a fridge and freezer (more challenging if you have a big chest freezer). In a power cut You'll want to switch most things off before starting the generator, manually switching to generator and then switching a few items back on.
It won't run a standard kettle or anything electrical heating.
There are battery systems with gateways that provide an uninterrupted power supply.
https://www.lewden.com/products/isolation-switches...
Fitted, with tails, generator socket, appropriate MCB and an earth rod Id say you be about £1k plus VAT, assuming it’s short and easy runs.
And get at least 5kva
Fitted, with tails, generator socket, appropriate MCB and an earth rod Id say you be about £1k plus VAT, assuming it’s short and easy runs.
And get at least 5kva
And make sure it cant back feed to the mains at all.
We had one in an old house, cant comment on the install as it was there when we moved in, also cant remember what size geny it was, it was pretty big tho, but its surprising how little it could run without struggling. It defiantly used to complain when the freezer kicked in
We had one in an old house, cant comment on the install as it was there when we moved in, also cant remember what size geny it was, it was pretty big tho, but its surprising how little it could run without struggling. It defiantly used to complain when the freezer kicked in
3kW is plenty for running fridge, freezer, pumps for CH etc, a bunch of LED lights.
Not good for cooker, electric shower and so on.
Check the wattage of kettles toasters etc etc.
Power quality may be suspect, so I'd be cautious about running some things from it.
It could be a lot of work to install properly.
Not good for cooker, electric shower and so on.
Check the wattage of kettles toasters etc etc.
Power quality may be suspect, so I'd be cautious about running some things from it.
It could be a lot of work to install properly.
Ours is a 7kw petrol job, runs everything needed in the house including the one oven or ring if need be. We have a changeover switch in the cupboard and remote key start.
After storm eiwan it's just done 5 days running & proven it's worth! Though I will be moving it to make refueling easier as I've been away & the Mrs has been moaning about the access.
After storm eiwan it's just done 5 days running & proven it's worth! Though I will be moving it to make refueling easier as I've been away & the Mrs has been moaning about the access.
Evanivitch said:
You'll need amanual changeover switch.
This.Either a manual 'break before make' change over switch, that can only connect to one or other power source never both.
Or an automatic changeover unit that does the same thing, but automatically switches to mains when its available and genny when not.
The other option is a UPS battery/inverter based solution, which will typically kick in fast enough to appear seamless to most things.
Dr Mike Oxgreen said:
Who’s gonna suggest putting a 13 Amp plug onto the generator and sticking it into a wall socket? 
A friends Dad did something very simialr, about 20-25 years ago. You'll have to excuse the exact technical details, but:
They lived in a rural part of the area where trees would sometimes take down the cables in winter, and it was usually a couple of days or more before things were back on. His Dad was a head engineering supervisor type bloke at a local factory, and was always making and repairing machinery in his garage at home as a bit of a hobby.
He fixed up a big old diesel generator and decided to keep it for their power cuts. He made up some kind of fuse that could plug into the old consumer unit (or rather fuse board as it was) alongside the other fuses, but it had cables trailing out of it to the generator.
He would switch off main the incoming power switch on the fuse board, and then plug in his wired fuse, and start the generator.
Even at the time his son joked that it was 'really dodgy' and mentioned about accidentally backfilling the grid with their generator power if you didn't turn the consumer unit switch off.
Gtom said:
Dr Mike Oxgreen said:
Who’s gonna suggest putting a 13 Amp plug onto the generator and sticking it into a wall socket?
Nothing wrong with the death lead……tog said:
Gtom said:
Dr Mike Oxgreen said:
Who’s gonna suggest putting a 13 Amp plug onto the generator and sticking it into a wall socket?
Nothing wrong with the death lead……But the are two major issues with it.
- 1) you have a live power on the pins, if you were to plug one end into a power source and then touch the other.
- 2) as per the above, if you fail to isolate the incoming power supply, you will back feed power into the grid and or grid into the genny.
So you also significantly risk electrocuting the maintenance teams working on the repair, and or blowing up the generator connecting to the grid without and phase matching.
Just a little update, I'll be relocating ours to allow easier access, it's currently under the house in a dark dingy Crawlspace that's not easy to refuel it. Also from a fire safety point of view it's not great but it was already fitted when we bought the house.
I'll be fitting it in a steel box outside the house with ventilation, spare fuel at hand etc.
Has proved it's worth though this year! Mrs ended up cooking for the neighbours and had full services including the oven throughout our nearly week long outage. Unlike the rest of the village.
This is the 125a changeover switch recently upgraded that we use and fitted by the sparky when we had our distribution box upgraded recently.
https://www.ebay.co.uk/itm/253453017862?mkcid=16&a...
I'll be fitting it in a steel box outside the house with ventilation, spare fuel at hand etc.
Has proved it's worth though this year! Mrs ended up cooking for the neighbours and had full services including the oven throughout our nearly week long outage. Unlike the rest of the village.
This is the 125a changeover switch recently upgraded that we use and fitted by the sparky when we had our distribution box upgraded recently.
https://www.ebay.co.uk/itm/253453017862?mkcid=16&a...
Edited by cptsideways on Sunday 2nd February 12:55
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