Microwave on low amp supply

[JohnH]

We are going to an event and the supply is only 6 amp. Is this sufficient to power a low wattage microwave? I cannot remember the formula for working out wattage to amperage etc.
I ask because that helps determine what we take in the way of food.
We have never tripped a circuit yet but have only used it on greater amp circuits.
John

 

[Welsh girl]

I don't use mine on a low amp rating as I think it would trip it.
I then use the skillet.
Especially if you can't reset it yourself.

 

[Techno]

Yes it should cope with nothing else on at the same time like fridge and battery charger

 

[pappajohn]

i reckon it may trip even with all other electrical goods turned off.

A 750watt m/w oven may take 1500watts for a few seconds on startup.

1500watts = 6.25amps

 

[Techno]

OP said a Low wattage microwave

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[SomeoneElse]

The 800W microwave fitted in our MH has an input rating of 1250W.
It runs successfully on our 1500W inverter, during operation the inverter says it is suppling 1.28kW.

6A x 230V = 1380W, you should be OK on a 6A supply, can you see the rating plate on the microwave?

Anyone know the powerfactor of a running microwave?

Gordon

 

[pappajohn]

OP said a Low wattage microwave

anything lower than 750watts you might just as well stand the food out under the sun to warm up.

 

[pappajohn]

The 800W microwave fitted in our MH has an input rating of 1250W.
It runs successfully on our 1500W inverter, during operation the inverter says it is suppling 1.28kW.

6A x 230V = 1380W, you should be OK on a 6A supply, can you see the rating plate on the microwave?

Anyone know the powerfactor of a running microwave?

Gordon

Input current and startup current are different...your calculation only allows 100watts for the startup surge current.

230v is a european 'harmonised standard' voltage....actual UK voltage is still around 240v.

 

[funflair]

We are running our 800 watt microwave on 6 amp Spanish volts no problem, as Techno says just make sure other 240 stuff is switched off.

Martin

 

[cmcardle75]

Input current and startup current are different...your calculation only allows 100watts for the startup surge current.

230v is a european 'harmonised standard' voltage....actual UK voltage is still around 240v.

Remember that the typical Type B MCB is rated at continuous current. It allows plenty for startup surges already. Indeed, you need 5 times its rated value to be certain of tripping it instantaneously. You can manage double its rating for a period of many seconds.

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[pappajohn]

Remember that the typical Type B MCB is rated at continuous current. It allows plenty for startup surges already. Indeed, you need 5 times its rated value to be certain of tripping it instantaneously. You can manage double its rating for a period of many seconds.

agreed, but many hookup posts and motorhome fuseboards have type C Breakers.

 

[Ed Excel]

The 800W microwave fitted in our MH has an input rating of 1250W.
It runs successfully on our 1500W inverter, during operation the inverter says it is suppling 1.28kW.

6A x 230V = 1380W, you should be OK on a 6A supply, can you see the rating plate on the microwave?

Anyone know the powerfactor of a running microwave?

Gordon

The input rating on your M/W includes the turntable motor, light, controls, etc, but not the starting load. Power on start up will be of the order of 1600W. Your inverter is no doubt capable of 3000W, for a short time, so it's going to be happy with your M/W start up load.

You don't say what size circuit protection supplies the M/W.

Note: p.f. of a microwave oven on defrost setting can be around 0.5

 

[Reallyretired]

If I had a microwave (I took mine out to save space and weight) then I would run it off the inverter. If I had ehu I would use that to recharge the batteries as normal so no risk of blowing the ehu.

 

[cmcardle75]

agreed, but many hookup posts and motorhome fuseboards have type C Breakers.

A Type C breaker is even harder to trip instantaneously. It has the same thermal trip curve as a Type B, but the instantaneous action is set at a higher multiple.

Usually reserved for lifts and other devices that expect massive inrush currents. Fitted by campsites to reduce the need to constantly reset the breakers!