15 amp fuse used instead of 20 amp
Could using a 15 amp use instead of 20 amp cause intermittent failure of microwave to do anything? control panel completely dark.
Depending on the maximum power used by the microwave and the voltage of your power supply roughly determines the current required. e.g. 1200W Microwave 120V AC power supply = approx. current of 10 Amps. or 1200W microwave 230V AC power supply = approx. current of 5.21 Amps. (Formula I=P/V - this is only approximate, but to use as a guide is close enough)
So therefore a 15 Amp fuse should be more than capable of handling the current required before it fails. (I assume that you mean the fuse in the microwave oven.)
Has it failed? If so that means that there is a fault further into the circuit and the fuse is just doing its job, which is protecting the equipment from further damage and also the user by preventing electrocution or even a possible fire due to a fault condition.
The best way to determine what the correct value fuse should be is to look up the model number of your microwave and see what the manufacturer specifies.
If the fuse has not blown, unless the fuse is loose in the fuse holder it would be very unusual for it to cause intermittent power problems. It is more likely to be a loose connection or dry solder joint in the power supply path or even a dry joint solder connection on the control board.
If you don't know what you are doing leave microwave ovens alone. Even with the power disconnected it can still deliver a nasty shock, even fatal depending on your medical condition, if you go looking inside one to see what the problem is and inadvertently touch the wrong thing."
"Hi @ Jason Moran,
It is better not to use it.
Here’s a link that explains it better then I can. See Voltage Rating Fuses section
If possible use a higher voltage rated fuse with the same current rating rather than a lower voltage rated one."