Why would a microwave oven not work properly on a petrol generator?

Andy From Sligo

https://www.boards.ie/discussion/comment/123111764#Comment_123111764

try totalling up the wattage of the items roughly when all added up together and then add some more wattage , then get a 12v inverter at the nominal output of what you totalled up/estimated - the 'peak' output on the inverter specs is what it could do if pushed and for a very limited time so you dont want to be basing on that you want to be looking at the nominal output, could be talking seconds , without damaging the inverter. yes you should run / idle the engine while using it so it doesnt run down the 12v battery.

So you can get 12v inverters that plug in the cigarette lighters in all kinds of maximum nominal wattage outputs - the general rule is that the more the higher wattage inverter you buy the more expensive it will be to buy, and normally the hotter the casing will be in operation - also thehigher wattage ones you get may be too powerful for the 12v lighter socket and blow the lighter socket fuse in the car , however if you get a high wattage inverter they normally give you a thick lead with 2 crocodile connectors on it whereby you can bypass the lighter socket and put the crocodile clips straight onto the 12volt battery instead to work it.

good luck.

john jameson

Thanks for that!!

I had a look at some figures today or tried anyway to understand them so based on what I learned today my berlingo should happly support a 2000w inverter I understand there will be some loss running the inverter.. some in the extension lead etc but should do all I want it to do! I could just meet in the middle with a 1500w inverter!

Really the reason for the inverter will be to keep our phones charged up once in the day will do that ... charge the kids tablets and also charge any battery lighting that we may need at night!

I could even use it to chill the deep freeze for an hour cuple times a day as it only consumses 75watts .

I don't think I have enough need on it to max it as I have a solid fuel stove for room heat and hot water for dishes and showers etc

A dubble gas camping stove for cooking and Internet is through a mobile phone hotspot.

In all it may be a better option than a genny roaring out the back !

Now to look in to a suitable pure sine inverter

Thanks agen for message .

Lenar3556

Inverters a great solution, and pure sine wave is the way to go.

But watch the size - 1500w is very big, potentially drawing 150A from your vans alternator, which is probably way above what it is deigned for - you would need to check it out.

400W might be a safer bet.

Andy From Sligo

https://www.boards.ie/discussion/comment/123113913#Comment_123113913

your welcome , 2000w is a very heavy one . I wouldnt chance it … if you had one of these large 12v 'leisure battery' as they call them and a good way of charging it possibly , but with a normal 12v battery and Van alternater be very careful. even if it were a lorry with 24v battery and a 24v to 230v inverter might be ok .

If you look for an inverter try have a look on Amazon UK and look for 'dispatches from Amazon' you should get it through without customs and without getting hold up in customs - if you find a norn ireland parcel motel place (like we have one just over the border in Belcoo) then you can select postage to UK (northern ireland) and pick it up just over the border.

john jameson

https://www.boards.ie/discussion/comment/123114059#Comment_123114059

Yes maybe your right if it's only going to be for charging phones tablets camping lights it would be good enough!

It would also run the circulation pump as it doesn't draw that much and the small box freezer .

Pure sine wave seems the way to go surly!

The Continental Op

Another point to bear in mind with Lead Acid (car batteries) is that they only good for half their rated capacity. So a fully charged 100Amp hour car battery is good for 50Amp. Using more power than that in one go seriously reduces the life of the battery.

Dave_D_Rave

That generator should be 50Hz see attached. I once had a Honda operating at 40Hz and like that some equipment worked and others didnt

Problem for me was in the voltage regulation circuit and Governor control.

Incorrect capacitor fitted by someone in a previous life and Governor adjusted to give 230v AC output

35098_0.jpg

SodiumCooled

I have a 6kW generator rated at 50Hz (it’s not an inverter though) the microwave sounds a bit different but it is operating correctly heating food and working fine. Whether it will shorten its life is another question but for now it’s working fine. My generator is more than adequate for the load it can easily boil a kettle though 2.8kW should be well able for a microwave - the 60Hz is a different matter but doubt mine is maintaining 50Hz and certainly not pure sine I would think.

kildarejohn

As Dave-Rave says in previous post, the frequency (50/60Hz) depends on the Governor. If the generator is a simple set up without sophisticated electronic control, then the frequency directly depends on the RPM its running at. So reducing the frequency to 50Hz might be as simple as giving a 10 degree turn to an adjustment screw on the carburetor.

Andy From Sligo

https://www.boards.ie/discussion/comment/123119758#Comment_123119758

if you dropped the revs in engine by adjusting carburettor would it not also reduce the 233v AC voltage?

The Continental Op

https://www.boards.ie/discussion/comment/123120125#Comment_123120125

Would that be a problem 220V would be fine?

Andy From Sligo

https://www.boards.ie/discussion/comment/123120151#Comment_123120151

no, your right 220v ac would be fine

kildarejohn

there's several videos on Youtube about adjusting generator governor, e.g.

Generator Governor Adjustment

Andy From Sligo

https://www.boards.ie/discussion/comment/123120632#Comment_123120632

Thank you - have given the generator back now, but its good to know should we get one for future thank you

Antenna

regarding mains frequency stability, an ESB story from 2012:

South Kerry in timezone of its own as electric clocks go cuckoo

Quote "For electric clocks to function properly a minimum frequency of 50Hz is needed,"

Of course this report should have said an exact frequency of 50 Hz not a "minimum"! (or averaged out over time to be fairly accurately 50Hz )

10-10-20

https://www.boards.ie/discussion/comment/123123028#Comment_123123028

I recall being in Eirgrid's office around Wilton Terrace (before they moved to the Oval) and they had a big digital map of Ireland setup in what for all intents and purposes looked like a school stage setup with desks all around it. They sat around monitoring the frequency across the Island so that it was all within a tight spec. That's why it's surprising to hear that a generator was out of sync with the network - I thought that was all highly coordinated!

Antenna

QUOTE:"That's why it's surprising to hear that a generator was out of sync with the network "

the whole area concerned was temporarily off the national power grid and supplied as an 'island' as it were by temporary portable generators. So not being in synch with the national grid did not matter (but did of course matter for the clocks using the mains frequency to keep time)

Andy From Sligo

one thing I have noted from borrowing this generator is that it wasnt used to its full capacity/potential . It was a 2.8watt nominal output. I put an energy meter on it to measure how much we were using from it, roughly 300-350watt is what we were using. so if we are to buy a generator a 2.8kw like that one would be overkill possibly , and it used a fair amount of petrol too - but again a more lower wattage petrol generator would be more economical , use less petrol too wouldnt it? - would it be less noisier as well? - in other words, with petrol generators is it a general rule that the more kw output generator you get the more noisier are they?

The Continental Op

More power output bigger engine more noise. BUT with a bit of tinkering you can make a generator near silent. I used to run an old army petrol generator for battery charging and we replaced the exhaust with a flexible metal exhaust hose with a big motorbike exhaust on the end of it. You'd hardly know it was running.

Its the same with any generator some are cheap nasty and noisy and others are a lot more expensive with a much better exhaust system. As an example you won't want to pay the money for this https://store.honda.co.uk/eu10i-1000w-portable-generator/11541448.html but its quite.

CelticRambler

https://www.boards.ie/discussion/comment/123130744#Comment_123130744

https://www.boards.ie/discussion/comment/123114419#Comment_123114419

For what you need, you could learn a lot from those of us who hang out in the Motorhome forum :-)

Apart from being careful not to ask too much of a factory-fitted alternator, the rest of the system is dead easy to buy and configure, and being off-grid is pretty much the de facto normal state for most younger and middle-aged motorhomers.

In any case, you've spotted one of the major limitations of generators: the power they provide is "all or nothing" - if you want 2.5kW just-in-case, you're going to get 2.5kW whether you need it or not. That's where having a good-sized LiFePO4 leisure battery and a decent inverter works so much better. I have a 2000W (4000W peak) inverter drawing from a 200Ah LiFePO4 battery and it runs fridge-freezer, microwave, kettle, vacuum cleaner, laptop/phone chargers (if I need it to) and anything else I've tested so far, no problems whatsoever. The primary benefit of this arrangement is that you can draw the 2kW whenever you need it, and if you don't, the amps are there waiting to be used later on.

For emergency situations, you're going to need some way to (re)charge the battery from time to time. If you have fuel for the engine, then a DC-to-DC charge controller spec'd for LiFePO4 batteries (expensive) would let you safely connect to your van's alternator.

My inverter is one of these :

https://greencell.global/en/power-inverters/2425-green-cell-car-power-inverter-converter-12v-to-230v-2000w4000w-pure-sine.html

(only regret is that I probably should have gone for the 3000/6000 model because some of my power tools draw 2.5-2.7kW)

Andy From Sligo

https://www.boards.ie/discussion/comment/123130934#Comment_123130934

that looks extremely good price for that inverter there - cheaper than the petrol generators I have been looking at . The wife has a hybrid car, i wonder how one of these would run hooking up to the 12v battery of her hybrid next power cut - the 400v DC battery in her car charges up the 12v battery in her car by means of DC-DC converter and then her petrol engine in it acts as a generator to charge the 400v Battery. - Might work. As I say i only really need 300w of power to work the boiler and central heating pump , run a couple of CFL/LED lights and charge up the laptop and phones and torches