# Problems with 120V microwave



## olley (May 1, 2005)

Hi ever since we got the brave the microwave has tripped out its 15amp breaker on UK power after running for a few mins. its fine on the genny.

Today I finally got round to measuring the power its taking. 230v 18.6amps, genny power 110v 13.4amps, The only thing I can think of to cause this is the difference in the hz.

Anybody else found this?

Olley


----------



## 101411 (Oct 15, 2006)

Hi Olley

The answer to your problem is the breaker is too small, you have a 15 amp breaker but the microwave is drawing 18.6 amp. You could upgrade the breaker IF THE CABLES ARE CAPABLE OF TAKING THE BIGGER LOAD. Check they are before you upgrade or you could find your cooking more than the stuff in the oven!!!!

Hope that helps

Dazzer


----------



## Scotjimland (May 23, 2005)

Hi Olley 

Funny you should mention this today.. last night our micro stopped working .. 
I went to check the 15A breaker, it hadn't tripped but was 'buzzing' , sounded like it was arcing inside.. I switched off and on a few times and that got it working but I reckon the breaker is too small .. I would think your assumption is correct.. it takes more juice on 50 hz ..


----------



## olley (May 1, 2005)

Hi guys I know the breaker is to small on mains, but thats because it don't like the 50hz. (It runs quieter on the genny as well)

I appear to have two options, change the breaker or change the M/W. As there is a 20amp breaker next to it I can check wire sizes, if they are the same then I will upgrade the breaker. Mind you 230v m/w are as cheap as chips nowadays.

Another downside is that the 1800watt inverter trips out as soon as I try to run the m/w from it. I also wonder if running the m/w on 50hz shortens its life.

Ho hum the joys of owning an RV.

Olley


----------



## 101368 (Oct 12, 2006)

olley said:


> Hi guys I know the breaker is to small on mains, but thats because it don't like the 50hz. (It runs quieter on the genny as well)
> 
> I appear to have two options, change the breaker or change the M/W. As there is a 20amp breaker next to it I can check wire sizes, if they are the same then I will upgrade the breaker. Mind you 230v m/w are as cheap as chips nowadays.
> 
> ...


If it really is taking twice as much power when on 230v 50Hz then I expect it's life to be fairly short and it's ending possibly spectacular. Personally I'd go for a new microwave sooner rather than later.


----------



## olley (May 1, 2005)

Hi emgee its more like 40% more, but thats still a lot more than it was designed to use.

I think I will have a look round to see what will fit in the gap. 

Olley


----------



## 101368 (Oct 12, 2006)

olley said:


> Hi emgee its more like 40% more, but thats still a lot more than it was designed to use.
> 
> I think I will have a look round to see what will fit in the gap.
> 
> Olley


Maybe I misunderstood the figures you quoted but I make 230V at 18.6A 4278 Watts and 110V at 13.4A 1474 Watts. So it's actually three times. That seems so unlikely that I suspect we're misunderstanding each other.


----------



## Scotjimland (May 23, 2005)

emgee said:


> olley said:
> 
> 
> > Hi emgee its more like 40% more, but thats still a lot more than it was designed to use.
> ...


Hi emgee 
Just to clarify (I hope)

Both readings are at the 15A breaker, which is either fed from the mains via the transformer or direct from the genny.

so both voltages are the same, 110 and not 230v and the Hz is 50 and 60 respectively.


----------



## 101368 (Oct 12, 2006)

ScotJimland said:


> emgee said:
> 
> 
> > olley said:
> ...


Right that makes sense. In which case there's almost certainly a transformer in the microwave that's saturating on 50Hz but ok on it's rated 60Hz.

Don't run it on 50Hz would my advice.


----------



## RAH (Apr 22, 2007)

I'm really ignorant when it comes to electricity, but isn't there some kind of device to modulate 50mhz to 60? I would have thought that if there was something then everyone would have it onboard by now.


----------



## olley (May 1, 2005)

hi RAH cycle changers are available, but they ain't cheap.  Be cheaper to buy a yank 110v inverter.

their was an option when new to have a 2kw prosine fitted instead of the std. 300watt, pity it wasn't taken up.

The answer for the time being is to only run it off the genny.

Olley


----------

