Invertor

[mjm]

Can some give me a bit of advice please.

Maplin sell a 800W DC-AC Invertor for £139.99 what I what to run off this is a Microwave oven its is rated at 750W.
First will this Invertor run the oven as it close to the wattage.
Second has anyone else run Microwave ovens for Invertors.
Third what drain on batteries is likely I have two 100amp hours domestic batteries.
Fourth is £139.99 a good price.

Thanks you to all who reply


Mike



<hr width=100% size=1>

 

[ccscott49]

139.99 is a good price for a 800w inverter. An 750 watt, microwave does not mean it draws 750watts from the mains. Check on the back of the machine as to it's actual consumption, if it says, 2 amps at 230 volts or somesuch, multiply the voltage by the amps, to give you the actual power consumption in watts. ie. 2 x 230 = 460 watts. Most modern invertors are about 95% efficient, some better, so you need to do that little calculation aswell. I run a microwave with an invertor all the time without problems, admittedly a much bigger one at 1800 watts. Your battery capacity is adequate for a short time, you can work it out, if your micro takes 480 watts, divide that by the voltage of your batteries, (12 volts), this will give you a ballpark figure of 40 amps, which is quite a high load. When running the micro, I would have an engine running. Hope this helps a little, PM me if you need anymore help.

<hr width=100% size=1>

 

[Guest]

There are often 800W Inverters (new) on ebay. They tend to go for around £85.

<hr width=100% size=1>

 

[colvic]

Just bought one off e-bay for a total of £44. 800watts max surge of 1200w. Guaranteed for 12 months.

Phil

<hr width=100% size=1>

 

[mjm]

well I am off to ebay now thanks for the help all
mike

<hr width=100% size=1>

 

[VicS]

Your example calculation is rather misleading as it implies that the power consumption of a microwave could be much less than its rated output!!!!!! In fact of course it is very much the other way round.

My 800 watt microwave consumes 1420 watts or approx 6amps.

So the answer as to whether 800watt inverter will run a 750w microwave is very definitely NO.


<hr width=100% size=1>

 

[Aeolus_IV]

Isn't it also worth noting that unless you're using a pure sine wave inverter you'll also get loose power when driving a basic impeadance load off a pseudo-sine wave inverter, so there is an additional factor to take into account here?

Jeff.

<hr width=100% size=1>

 

[ccscott49]

800 watts of microwave power is not the same, but I agree my answer maybe misleading. I'll remove it.

<hr width=100% size=1>

 

[tr7v8]

800watts is actually the gross magnetron output eg. the bit that emits the waves that heat the food. The actual start wattage could and probably is twice that!
Their are some low wattage ones Samsungactually do a 500W one that does 12V all it means is that the inverters built in. From memory it takes around 85Amps at 12V!!!!! Do a search through previous posts as I posted the spec a while ago.

<hr width=100% size=1>Jim

Draco 2500

 

[pvb]

Bigger inverter, or....

For a regular 750w microwave, you'd need at least a 1500w inverter. If you don't need an inverter for anything else, it might be cheaper to buy a Samsung 12volt microwave. It has a 750w cooking power, draws 65A and costs around £230. With your fairly limited battery capacity, it would probably be necessary to run the engine whilst using the microwave.

<hr width=100% size=1>

 

[IanBBA]

Re: Bigger inverter, or....

You can buy an aweful lot of Calor gas with £230!

<hr width=100% size=1>

 

[qsiv]

Re: Bigger inverter, or....

I'd agree - but we're an all electric boat, and I love the freedom from gas worries. We've a bit more battery capacity than most (about 1200 amp hours), and have a 3 Kw (and 5 kw genny) inverter. The lack of worry over gas supplies coupled with the safety angle is a huge plus. The only real negative is that to run the oven (or more than two rings of the cooker) means running the genny - but as you cant hear that on deck, and only just hear it down below, it isnt a huge issue.

<hr width=100% size=1>