microwave tripping breaker...what to look for?

[jeepbluetj]

sailorboy has it right I think. If you plug the micro into one of the port outlets and it still blows the main, the main breaker is bad. (Or was replaced with something less than 30A)

If it then blows the port breaker, the micro is likely bad (and cheap enough to just replace) AND the stbd breaker is bad.

I'll assume the port/stbd breakers are 15a and the main is 30a.

[Jcolman]

Originally Posted by jeepbluetj

sailorboy has it right I think. If you plug the micro into one of the port outlets and it still blows the main, the main breaker is bad. (Or was replaced with something less than 30A)

If it then blows the port breaker, the micro is likely bad (and cheap enough to just replace) AND the stbd breaker is bad.

I'll assume the port/stbd breakers are 15a and the main is 30a.

Thanks. I'll be giving this a try Sunday. Keeping my fingers crossed that it's the microwave that's bad.

But one thing that I can't figure out. If the main breaker is bad, wouldn't you think it would blow when I plug the heater and refrigerator in?

[jeepbluetj]

Changing the breaker is pretty brain-dead simple too. Just remember to unplug the boat .

[sailorboy1]

Originally Posted by Jcolman

Thanks. I'll be giving this a try Sunday. Keeping my fingers crossed that it's the microwave that's bad.

But one thing that I can't figure out. If the main breaker is bad, wouldn't you think it would blow when I plug the heater and refrigerator in?

You would think, but again it is all a matter of the amp loads and we don't really know. Be aware that you could have more than 1 problem.

But if it was me I would be hoping that the problem is the breaker as that will cost a lot less to fix and would take just a few minutes.

[Jcolman]

Originally Posted by sailorboy1

You would think, but again it is all a matter of the amp loads and we don't really know. Be aware that you could have more than 1 problem.

But if it was me I would be hoping that the problem is the breaker as that will cost a lot less to fix and would take just a few minutes.

Good point...IF it's just a faulty breaker and not something more serious.

[Jcolman]

Originally Posted by jeepbluetj

Changing the breaker is pretty brain-dead simple too. Just remember to unplug the boat .

I'll stick a screwdriver into the electrical outlet just to make sure it's unplugged.

[sailorboy1]

Originally Posted by Jcolman

I'll stick a screwdriver into the electrical outlet just to make sure it's unplugged.

I've always said that the number 1 rule of electrical safety is - don't lick live wires!

[bill good]

Originally Posted by Jcolman

on the breaker or microwave?

In the microwave. Repair or replace.

[AfterHoursNLCT]

Originally Posted by Jcolman

I'll stick a screwdriver into the electrical outlet just to make sure it's unplugged.

Gotta admit, I chuckled on that one... LL

[Raider Curt]

Originally Posted by sailorboy1

no it wouldn't, just drop the voltage because it will restrict the circuit

Better look back over Ohm's law. If voltage is lowered and resistance remains constant, Amperage will increase.

[Jcolman]

Update:

I'm at the boat for a couple of days. So the first thing I did, based on your suggestions, was to move the microwave to the port side and plug it into another outlet. Bingo! It works fine. I should have tried this earlier but it never occurred to me. This particular outlet is labeled "110 AC". Obviously the PO used this outlet for his AC so I suppose it's a bit "beefier" than the other outlets. Anyway, thanks guys for all your help. I guess the starboard outlets ( at least the one I tried) is too weak to handle the load of a microwave.

However I'm surprised that the "sbd" breaker didn't trip and the master did on my earlier attempts.

[sailorboy1]

replace that stbd breaker!

[Roy M]

It's not "beefier", its just carrying less load. Turn off the breaker and see what doesn't work. The master breaker shuts down when the load exceeds 30 amps, the individual breakers shut down at 15 (or 20).

[Jcolman]

Originally Posted by sailorboy1

replace that stbd breaker!

Will do first thing Monday.

[Jcolman]

Originally Posted by Roy M

It's not "beefier", its just carrying less load. Turn off the breaker and see what doesn't work. The master breaker shuts down when the load exceeds 30 amps, the individual breakers shut down at 15 (or 20).

Right now I have my refrigerator and space heater plugged into one of the starboard outlets. They both work fine but I'll replace the breaker in the panel anyway. What puzzles me is why the PO labeled a specific port outlet "110 AC". Perhaps it's the only outlet designed to carry 20 amps while the others are 15 amps?