MICROWAVE OVEN - CIRCUIT BREAKER

Does anyone have any idea what size circuit breaker is required for a microwave oven (assume 850 watts) running off a Victron inverter?
There is power to oven (front panel lights up), however, as soon as it starts heating (big draw 5 to 10 secs after start
) the circuit breaker trips out.
Any help would be appreciated?


Posts: 2925

Date Joined: 27/12/06

circuit breaker

Thu, 2015-01-01 12:52

the circuit breaker is only there to protect your cable, so I would need to know your cable size?

generally a 2.5mm2 uses a 16A CB, but I dont think your microwave would be spiking over 8A

Posts: 146

Date Joined: 14/11/10

THANKS....

Thu, 2015-01-01 13:17

Thanks Rig.
I'm going to go down to boat over the next couple of days...will get cable/circuit breaker sizes/specs and post back for your advice - it's all a black art to me mate...lol?

crano's picture

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Date Joined: 04/11/09

 The circuit breaker is just

Thu, 2015-01-01 15:26

 The circuit breaker is just doing what it is supposed to do.The microwave will be just pulling too much current for the inverter.Aparently the watts rating of a microwave is not really a good guide as to the amount of current they pull.Mr Google will tell you what size inverter you would need to run it.

Dale's picture

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Date Joined: 13/09/05

 The 800 watts is basically

Thu, 2015-01-01 18:21

 The 800 watts is basically what's produced to micro wave food, it has nothing to do with what's drawn from the battery. The typical draw would be around 150 amps at 12 volts, The total effective draw on the battery is about 2000 watts which is killing your battery in the process.

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"Just because you are a Character, Doesn't mean you have Character."

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Posts: 146

Date Joined: 14/11/10

THANKS...

Fri, 2015-01-02 14:53

Thanks for the responses fellas.
I am certain that the circuit breaker is less (probably around half) of the 150amps typical draw suggested by Dale?
(The microwave has it's own dedicated circuit breaker).
I'll see if it trips out on shore power, if it does, I'll try a higher rated circuit breaker, if not, then I'll have a closer look at the inverter's spec sheet.
What do you think?

Dale's picture

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Date Joined: 13/09/05

Fri, 2015-01-02 15:38

 Yeah try that, and ensure your wires are big enough for high currents.

____________________________________________________________________________

"Just because you are a Character, Doesn't mean you have Character."

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Date Joined: 14/11/10

CIRCUIT BREAKER``

Thu, 2015-01-08 10:43

I tried the microwave on shore power - it worked as expected, no problems at all.
However, on the batteries (through the Victron Inverter) - it again tripped the circuit breaker after about 5-10 secs?
Any suggestions on possible causes and/or what to try next would be greatly appreciated?
I'm thinking next step may be to swap out the existing circuit breaker (100AMP/42VDC) for a higher rated one - say 150 AMP?