6.7kva Generator to Power Home?

KaiserLu

Hi all,

I've had a generator since 2022 and never turned on. Living in a dormer bungalow. I'm looking to install a changeover switch next month. Have a baby and another one due in June and after the last outage (4 days) we need to make sure that we have provision in place for the next storm. According to my Solar App the house pulls 0.78kw in average when nothing too hard on the electricity is switched on (dryer, oven, etc)

I just need our lights (LEDs), water (submersible pump), fridge freezer and heat (grant boiler) powered. We have a gas stove to cook with. We can do without TV etc, just want to make sure the babies and wife are safe and warm.

Will a 6.7kva do the job? I can't seem to get a straight answer anywhere online.

JohnySwan

https://www.boards.ie/discussion/2058396979/6-7kva-generator-to-power-home

Yes

10-10-20

It's probably oversized really, arounda 4kva or 4kw should be fine and more available.

JohnySwan

https://www.boards.ie/discussion/comment/123182447#Comment_123182447

Op already has it.

10-10-20

https://www.boards.ie/discussion/comment/123182522#Comment_123182522

I see that they have a genny, but the size isn't stated. Plus they only need "lights (LEDs), water (submersible pump), fridge freezer and heat (grant boiler) powered" - that would all function off much less than 6.7kVa.

Jakey Rolling

The issue with sizing a genny to cover peak load, is that 90% of the time you are probably only pulling <500W so the genny is just idling wasting fuel and making noise. I have a genny left over from when we built the house, it gets run occasionally when we have power outages more than a few hours just to cool the fridge/freezer. We have a manual changeover switch but never hooked up this generator as I wouldn't trust it to blow our TV etc.

Have been waiting for battery prices to come down - once the current rush is over I'll be installing 20kWh+ of batteries and inverter. It will partly pay for itself through day/night load shifting, and be good to run the house for a week if we minimise usage (gas hob and wood stove covers heating)

KaiserLu

Sugar. Is there a chance I could blow appliances by having too large a genny?

topofthewind

You won’t blow appliances based on the size.

The main thing is whether it produces ‘clean’ power (that sensitive electronics like a laptop are suited to) or not.

The larger size won’t be a problem at all except that it will be expensive to run and you won’t be using a lot of the power it provides most of the time.

If it is an inverter generator then the power should be clean. You should check this online or in the manual.

You should be able to run everything in your house (though not all the heavy use items at once) except an electric shower or a heat pump as these typically require more than the 6000 watts (or so ) that your generator can produce.

I ran my house for eleven days on a 2800watt generator with no problems at all last month. On for about 1 and a half hours in the morning to cool the freezer and fridge. On again at about 5pm till bedtime.

Manual transfer switch too. I switched off the breaker for the shower, immersion and oven. We ran lights, tv, oil boiler, fridge/freezer and charged phones. On one of the days, I turned off all the breakers except the washing machine and ran it. it worked perfectly.

KaiserLu

How often were you having to refuel it?

topofthewind

The 212cc engine used approximately 1 litre of petrol per hour. As the tank holds 15 litres, I could refuel once every second day if I ran it for 7-8 hours a day. About €13 a day.

I heard from neighbours that some were spending €40 a day (one story of €100a day) to run their generators. It’s a consideration when sizing a generator as the big ones are thirsty.

Krombopulos Michael

Can any electrician install a manual transfer switch with generator hookup?

JohnySwan

https://www.boards.ie/discussion/comment/123203025#Comment_123203025

Yes, assuming they know how 🤔

MrMusician18

Get a battery system with an inverter that can charge from a generator. This way you can use a small cheap generator running at a high consistent load to charge the batteries.

Depending on the specs you will be able to run the Genny for a few hours then have quiet power for the rest of the time

JohnySwan

https://www.boards.ie/discussion/comment/123203095#Comment_123203095

That was always the issues I had with a genny, the noise is incredible.