How much power do I need?

[Medic101]

Hi All,

I'm hoping someone will be able to assist me with understanding what size generator I need. I find understanding power requirements all far too complicated. I would ask that you kindly keep the technical knowledge to yourselves, I find it very frustrating and irritating as I just cant get my head around it, all I'm looking for is for someone to point me in the direction of what size generator I would need.

I'm looking to power the following:

4x Lights, assume strip lightning as specifics are not yet known,
1x portable fan heater
1x kettle
2x phone chargers
2x laptops
1x TV & DVD player
Hot water system for a sink.

There is a good chance that all these items would be on at the same time.

Any help is greatly appreciated.

[beardy]

OK without going into all the technical details, I am sure that your average SON, 3N80 or SP7 will not be adequate, no matter how hard you pedal.

[NATURAL ANKLING]

Hi,

Hi All,

I'm hoping someone will be able to assist me with understanding what size generator I need. I find understanding power requirements all far too complicated. I would ask that you kindly keep the technical knowledge to yourselves, I find it very frustrating and irritating as I just cant get my head around it, all I'm looking for is for someone to point me in the direction of what size generator I would need.

I'm looking to power the following:

4x Lights, assume strip lightning as specifics are not yet known, - 5 A
1x portable fan heater - 13 A
1x kettle - 10A
2x phone chargers - 3 A
2x laptops - 3 A
1x TV & DVD player - 3 - 5 A
Hot water system for a sink. - 13 - 15 A
There is a good chance that all these items would be on at the same time.

Any help is greatly appreciated.

60 - 80 Amp consumer unit
Ring main
Uprated feed from main fuse

4 amps is one kilowatt (250 vac, mains) = 1unit.

This is actual rating for supply aproximate.

Actual power in watts is stated on the items on the lable on back or base of individual applicances.......................

[Medic101]

[/quote]

60 - 80 Amp consumer unit
Ring main
Uprated feed from main fuse

4 amps is one kilowatt (250 vac, mains) = 1unit.

This is actual rating for supply aproximate.

Actual power in watts is stated on the items on the lable on back or base of individual applicances.......................[/quote]

I'm sorry call me thick, stupid etc but this has just gone way over my head. I understand watts to a certain degree and know that every electrical product requires X, but that is not really helpful to me in determining what size generator I need. Anything that is electrical just gets me in a fluster and I panic as its one of the few things I just physically can not grasp.

[beardy]

You are looking at about 15 Kilowatts of power.

The biggest variable is your sink heater, I was guessing at 7KW for that.

The chargers are too small to consider alongside the others and the laptop can probably be ignored too alongside them.

Most devices will have the power input that they take written on them somewhere, just add them all up and get something a little bit bigger.

[Medic101]

Lets go with 7KW for now for ease, based on that what size generator would I require as they have their output as KVA. I assume these are not the same? Or am I really that thick

[beardy]

Watts are Volts times Amps, so KVA could well be KW.
I dont know why they would say VA instead of Watts, see if somebody with more experience of generators posts.

[Tigerbiten]

I'd get a Kilo-A-Watt meter and see how much each appliance draws.
That way you can work out how much power you need.
But at a very rough guestimate I get around 6-7 kW or 7.5-9 kVA.
So a 10 kVA generator "should" work.
But I've no idea how much overhead a genny needs to be safe.

[beardy]

So what is the difference between a Watt and a VA?
As you have different values for both.

I was working on both kettle and fan heater being 3KW each, 7KW for the water heater and another 2KW for the lights and electronic things, mostly the TV.

[tatanab]

So what is the difference between a Watt and a VA?
As you have different values for both.

I was working on both kettle and fan heater being 3KW each, 7KW for the water heater and another 2KW for the lights and electronic things, mostly the TV.

Watts = VA for DC
For AC the power depends on whether the load is resistive, capacitive or inductive which is termed the power factor. This gives the VA rating explained here http://en.wikipedia.org/wiki/Power_factor Hence the different Watt and VA figures.

[NATURAL ANKLING]

Hi,
Sorry...mised the word generator

Some generator, big tank and a tow truck

[beardy]

There is a good chance that all these items would be on at the same time.

I think you may well find that having that degree of freedom is just too expensive. In order to have an affordable generator you may have to turn some things off while others are on.

Here is a reasonably understandable bit of guidance from Honda and they sell their generators with a Wattage rather VA figure.

http://powerequipment.honda.com/generat ... much-power

[RickH]

Does it all have to be electric?

Kettle & hot water (& heating too) could be gas powered. That would reduce the electricity need dramatically. Other factors may come into play as you have to deal with factors such as large heavy gas cannisters.

Rick.

[Tigerbiten]

It depends if you have a 2 kW or 3 kW fan heater. Mines rated at 2 kW.
Kettles are also between 2 and 3 kW. My kettle is 2.2 kW.
Domestic immersion heaters are usually rated at 3 kW.
It depends if it's a CRT or a flat panel TV. A flat panel can be as low as 50 watts. A CRT can pull 4x that.
Laptop chargers are around 65-90 watts, phone chargers are around 15 watts. So 200 watts for them.
Low power lights around 20 watts each.
So lights and electronic things less than 1 kW.
So I get 10 kW or 12.5 kVA max.

[Medic101]

Does it all have to be electric?

Kettle & hot water (& heating too) could be gas powered. That would reduce the electricity need dramatically. Other factors may come into play as you have to deal with factors such as large heavy gas cannisters.

Rick.

No that would not be an option and its just a temporary thing for a project I'm working on.