Magnum converter

[McGee]

I have a 2014 Berkshire motor home. The 300 amp fuse keeps blowing that feeds the 12 volts to the inverter. Replaced the batteries. Any one had this proublem?

[CHICKDOE]

what is the output wattage of the converter? 300 amps @12 volts is 3600 watts. if you have for example a 2000 watt inverter it shouldn't be drawing that much power. could something be wrong with the inverter? have you contacted manufacturer to see if they can help? it almost sounds like a short circuit but don't bet on that. does it blow immediately when you turn the inverter on? does it blow if you do not have any loads on the inverter? does it blow if you leave the inverter off?

[McGee]

Originally Posted by CHICKDOE

what is the output wattage of the converter? 300 amps @12 volts is 3600 watts. if you have for example a 2000 watt inverter it shouldn't be drawing that much power. could something be wrong with the inverter? have you contacted manufacturer to see if they can help? it almost sounds like a short circuit but don't bet on that. does it blow immediately when you turn the inverter on? does it blow if you do not have any loads on the inverter? does it blow if you leave the inverter off?

The problem happened while traveling down the highway. No the generator was off. We noticed it because the microwave wouldn’t work. The magnum control screen was blank. Got to my rev site plugged in to shore power changed fuse and all works again. Something goes wrong when inverter is on by its self while traveling. Any suggestions. Thanks McGee

[CHICKDOE]

i am not an expert! but if i read that data plate properly it says 3300 output watts as a surge. that close to the 3600 watts that the fuse is rated for (300 amps @ 12 volts). do you have a residential refrigerator? i'm just wondering if the refrigerator was on and using some inverter power and you created a surge from starting the micro wave whether you were approaching the limits of that fuse. this is just a guess. don't hold me to it.

if you have a residential refrigerator i'm assuming it runs ok off the inverter while travelling. that would seem to indicate that the inverter is running ok and that fuse is not seeing an excessive load. a test might be to disconnect the refrigerator and try the inverter all by itself to see if that fuse blows.

[McGee]

Originally Posted by CHICKDOE

i am not an expert! but if i read that data plate properly it says 3300 output watts as a surge. that close to the 3600 watts that the fuse is rated for (300 amps @ 12 volts). do you have a residential refrigerator? i'm just wondering if the refrigerator was on and using some inverter power and you created a surge from starting the micro wave whether you were approaching the limits of that fuse. this is just a guess. don't hold me to it.

if you have a residential refrigerator i'm assuming it runs ok off the inverter while travelling. that would seem to indicate that the inverter is running ok and that fuse is not seeing an excessive load. a test might be to disconnect the refrigerator and try the inverter all by itself to see if that fuse blows.

Yes it’s a residential frig. We didn’t get to use the microwave because the fuse had all ready blew. frig works great

[CHICKDOE]

again i am not an expert. but from what you say all works just fine when all you have running off the inverter is the refrigerator. that fuse blows when you try to add the microwave. and of course when the fuse blows the converter panel goes out as it is not getting any power.

it just sounds like the microwave and refrigerator combo are overloading the converter and fuse. and power required by the refrigerator varies with time depending upon whether it has the compressor on, ice maker, defrost, etc. and you do not have any control over when these cycles occur. you might be able to turn the ice maker and defrost cycles off. and depending upon the functions active with the refrigerator at the time you add the microwave it may or may not overload the inverter. so it might work one time and not another.

then only thought i would have would be to go to the inverter and study its status display panel. most will show something like dc volts / amps in and ac volts / amps out.
take a look at what it shows with just the refrigerator on and have somebody looking at it as the microwave is turned on. you might catch some info on the display panel before that fuse blows. but the fuse blowing says you are drawing more power that the circuit is designed to carry.

[cavie]

The AC output on that thing is 16.7 amps. You overdid it with the micro and the fridg on at the same time. You need to learn Energy Management.

[McGee]

Originally Posted by cavie

The AC output on that thing is 16.7 amps. You overdid it with the micro and the fridg on at the same time. You need to learn Energy Management.

The fuse was blown before we were going to use the microwave. That how we new we had a problem. The only thing running was the frig and a couple 12 volt interior lights. Just a thought could my alternator cause this while driving?

[rk06382]

Originally Posted by McGee

The fuse was blown before we were going to use the microwave. That how we new we had a problem. The only thing running was the frig and a couple 12 volt interior lights. Just a thought could my alternator cause this while driving?

I doubt your alternator would put out 300a.

If you are blowing 300a fuses, you should see a RV mech. 300a fuses are not cheap. I suspect you have a bad inverter.

Magnum T300 300 Amp Class T Fuse ($53.24)

[McGee]

Originally Posted by rk06382

I doubt your alternator would put out 300a.



If you are blowing 300a fuses, you should see a RV mech. 300a fuses are not cheap. I suspect you have a bad inverter.



Magnum T300 300 Amp Class T Fuse ($53.24)

Thanks for all the help. I’m thinking is the inverter also. I’m calling Magnum to day for more advice.