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William Sommerwerck William Sommerwerck is offline
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Default Sharp microwave arcs *through* front door

"Eeyore" wrote in message
...

William Sommerwerck wrote:
"Eeyore" wrote
Chris wrote:


I've got a ~2 year old microwave that has shown no previous signs
of trouble and is to all appearances in good working order. During
normal operation (melting butter on low power)...


That isn't a suitable load for a microwave, is it? You need some water
in there. No surprise it arced.


I don't think that's correct. Butter contains water and fat, both of

which
absorb microwaves. I've melted butter without problems.


Maybe the quantity wasn't enough?


I'm not sure. The "received knowledge" on such things is that if there's
nothing in the oven to absorb the microwaves, the magnetron will eventually
overheat (from the reflected unabsorbed energy). The lower the power
setting, the less likely this is to happen.

But overheating isn't arcing. Arcing requires a sharp metallic edge for the
electric field to build to a point where the air breaks down.