A good inveter

[NotJustin]

Hi, I have been looking for a sign wave inverter 24v to run the whole house, our use isn't that heavy. With storage heaters we are using 44 kwh per day average over the year. I won't run the storage heaters off the inverter! Just a few lights, computer, fridge freezer, washing machine and perhaps it might handle the electric cooker, though we have gas backup.

I'm just having trouble finding a good one, so often the reviews are very variable. I spend what I need to in order to get a good one.

Thanks for any ideas! Justin

[joth]

The daily kWh is largely irrelevant, what is the peak power in watts? (Or the peak amperage)

An electric cooker alone is 3kW plus, which is 100amps at 24V so fairly challenging to power on it's own. 

[NotJustin]

I've seen some inverters that can hande peak 7000w but are about 3000w. Here's one I was looking at: https://amzn.to/3ckGf13

[Temp]

https://www.cse.org.uk/advice/advice-and-support/how-much-electricity-am-i-using

 

Says..

Washing machine is 1200-3000W

Electric ovens 2000-2200

Freezer 200-400

Fridge 40-120

Computer 80-100

Call it 3500W to 6000W total

 

Without more info on the actual appliances I'd be looking for something that can do over 6000W continuously.  I suspect "Peak" figures are usually only guaranteed for a few seconds, eg to allow for motor start up.  

 

 

[NotJustin]

Looks about right. I have a portable meter that I have been checking watts. Though, of course, I'd run more carefully when on the inverter.

[SteamyTea]

Are these small (relatively) inverters OK with induction loads?

 

[NotJustin]

I'm just having trouble finding larger ones for sale.

[SteamyTea]

1 hour ago, NotJustin said:

I'm just having trouble finding larger ones for sale.

Have a look at inverters that can me installed together, rather than 1 inverter that can 'do the lot'.

It is a big ask to expect a single unit to deliver either 3W for a light bulb and then 7 kW or more for cooking.

[NotJustin]

cool, thanks, good plan

[Temp]

You also need to think about the battery and wiring carefully. 7000W at 24V = 290A. 

[SteamyTea]

120mm²  For a 10 metre run.

 

https://www.solar-wind.co.uk/info/dc-cable-wire-sizing-tool-low-voltage-drop-calculator

 

and the circuit breaker will be huge.

 

This sort of thing would need very careful design, probably better going up in DC voltage.

 

48V system would only need 35mm²

 

96V would only need 10mm²

 

Now you are into 'normal' cable sizes.

 

https://www.alibaba.com/product-detail/96-volt-5kw-6kw-7kw-power_62450791324.html?spm=a2700.7724857.normalList.127.159a6819aXCwIO

(This might be a grid tied inverter, but you get the point)

Edited September 23, 2020 by SteamyTea

[NotJustin]

I'd be quite happy to go up to 48v
Thanks for all this info, very usefull.

I've got plenty of "normal" cable, so it would be fine to go that way.

Edited September 24, 2020 by NotJustin

[joth]

Sticking at 48V makes sense, above that DC becomes more dangerous for humans to deal with.  (This is the reason PoE and phone networks both land at/around there)

https://electronics.stackexchange.com/questions/267789/how-safe-is-48v-dc/267797

[NotJustin]

I now have a 48v inverter, the seller tells me that it connects right at the mains, before my distribution box. Does anyone know how this gets wired up? I'm going to get an electician to do it, but I feel I need the info before that. Thank you.

[NotJustin]

Found this:

[NotJustin]

this is the imverter https://www.photonicuniverse.com/en/catalog/full/449-Iconica-5000W-48V-hybrid-pure-sine-wave-inverter-with-4000W-solar-input-80A-500V-MPPT-solar-controller-60A-mains-battery-charger-and-inbuilt-Bluetooth-No-battery-required.html

[Dave Jones]

https://www.victronenergy.com/inverters/phoenix-inverter-smart

 

[NotJustin]

I now have one of these:
https://www.photonicuniverse.com/en/catalog/full/449-Iconica-5000W-48V-hybrid-pure-sine-wave-inverter-with-4000W-solar-input-80A-500V-MPPT-solar-controller-60A-mains-battery-charger-and-inbuilt-Bluetooth-No-battery-required.html
 

It's just wiring it into the system I am unsure about

[NotJustin]

1 hour ago, Dave Jones said:

https://www.victronenergy.com/inverters/phoenix-inverter-smart

 

Is this for the connection diagrams?