Sine Wave

[Baggywrinkles1]

My whirlpool microwave will not work from the generator only from mains electric. Will this apply to all microwaves? I have been told it's the sine wave of the generator. As it's cheaper to change the microwave, but what make and how can I tell when I purchase one that it will work? The generator is a 16 kva 3 phase SDMO

 

[Jeva]

I've not heard of a geerator giving this roblem before, but I am aware that inverters with square or modified sine waves can give problems. I'd suggest that you check the generator frequency is spot on. (50Hz normally but chech the microwave specs). You can normally tweak the gen frequency by changing the generator engine speed. If it's a UK unit it may also need exactly 240Volts not a european 230volts.
Hope this helps.

 

[TrueBlue]

Very strange, rotating power sources - Mains supply and your own generator always produce "proper" sine wave power.

Perhaps your genny "hunts" and doesn't provide a stable voltage and / or there is electrical "noise" which upsets the Whirlpool.

Panasonic do a range of inverter microwaves (gets rid of heavy transformers) and inverter technology is more tolerant of messy power supply conditions.

Try before you buy in any case.

 

[ccscott49]

Never heard of a genny not running a microwave, but you do say its a 3 phase genny, with split phase for 230v? Maybe something wrong there, dunno but just maybe, check the herz and voltage. Best way to check herz (and sine wave shape) and voltage is with an oscilloscope, but not many around! A good multimeter should do the job.

 

[sarabande]

quite a number of oscilloscope software packages available, some even free.

http://www.picotech.com/picoscope-oscilloscope-software.html


Angus McDoon , IIRC, is a Nexpert on them.

 

[Cariadco]

Try this.....

Firstly, is the microwave working of the mains connected to the boat?or a shore based mains? I assume the mains on the boat.
Then as it's a 3 phase genni, then I assume it's 415 V phase to phase and 240 each phase to Neutral & Earth
You might have lost the 240v phase that feeds the socketoutlet circuit, that your trying to run the Microwave off.

Test the sockeoutlet ring (or spur) with a device you know that works. Then, depending if it's dead, then chase the circuit back to the Dist panel the Genni feeds into, and if no joy there, go back to the Genni terminals.

Be VERY careful, if it is a 415V gennie, a belt off 415 ie across phase to phase, will not just hurt, but probably kill you...!

Let us know how you get on.

Regards.

 

[ccscott49]

quite a number of oscilloscope software packages available, some even free.

http://www.picotech.com/picoscope-oscilloscope-software.html


Angus McDoon , IIRC, is a Nexpert on them.

Thanks for that, didnt even think software package!! How do you get an input into the confuser?

 

[sarabande]

Thanks for that, didnt even think software package!! How do you get an input into the confuser?

unless you use an intermediary device for bigger voltages / currents, etc, the sound card is the input device. Typically these have a max V of about 2v.

If you are mashing with domestic voltages, then something like this ?

http://www.gage-applied.com/Products/USB_Oscilloscopes/USB_Oscilloscope_CS121G11U.htm


It really needs Angus McD to advise in more (safer!) details

 

[Baggywrinkles1]

Hi Seasons Greetings!

Thanks for replies but some of them are way beyond me! I have just had another look with a volt meter, and in the marina the voltage is around 225volt on mains depending what I have on. with the generator on it,s 225 volt but the microwave goes bananas on the generator, the switches do all sorts of things they shouldn't do such as the start button starts to increase the cooking time the door button warning message comes on then goes off etc. Surely it has to be the sine wave? Everything else works ok on the boat. It's not easy to wire it on one of the other phases as they have different sockets, ie water heater and one for the cooker. True Blue hope your wife is OK now. I am just down the canal from you, Montauban, when are you coming back out?

 

[westernman]

May be the problem is that the generator is not a true generator (i.e. a constant speed generator), but one which uses some kind of inverter.

 

[daveyw]

I've not heard of a geerator giving this roblem before, but I am aware that inverters with square or modified sine waves can give problems. I'd suggest that you check the generator frequency is spot on. (50Hz normally but chech the microwave specs). You can normally tweak the gen frequency by changing the generator engine speed. If it's a UK unit it may also need exactly 240Volts not a european 230volts.
Hope this helps.

I have a 5kva diesel genny and that doesn't run flourescent lights?! It's a Sincro EW-AC http://www.sogagroup.com/FILES_UPLOAD/EW-AC manual_2.pdf

Just curious.

 

[Plomong]

I have a 5kva diesel genny and that doesn't run flourescent lights?! It's a Sincro EW-AC http://www.sogagroup.com/FILES_UPLOAD/EW-AC manual_2.pdf

Just curious.

The link you give is for a Welder !!! No wonder it won't run fluorescent lights !!!!

Plomong

 

[daveyw]

The link you give is for a Welder !!! No wonder it won't run fluorescent lights !!!!

Plomong

I wonder why my sockets were sparking!!! No. It has a 240V outlets too

 

[Plomong]

I wonder why my sockets were sparking!!! No. It has a 240V outlets too

Then that explains it. Your implied acceptance that your generator is really a welder generator tells all -- Don't try to run anything sensitive off that 240V, and a microwave is sensitive, its got electronics onboard usually these days.

Plomong