Power Inverter Fuses
Discussion
Probably a fairly basic question, my power inverter has 2x 30amp fuses fitted to it, does this mean it is capable of 60amps or just 30? Most the inverters I've viewed have this type of setup and even car audio equipment looks to have multiple fuses, blade type fuses normally fitted to them.
I've searched the Internet and can't find any info on this so if anyone could point me in the right direction would greatly appreciate the help.
I've searched the Internet and can't find any info on this so if anyone could point me in the right direction would greatly appreciate the help.
It was for a 500 watt inverter, I've now bought a 1000 watt inverter instead and it has 4 x 50amp fuses so I'm none the wiser.
For the 1000watt one (1000 continuous/2000 peak) you'd expect a fuse of at least 80 amps or more for dc input side (1000w ÷ 12v = 83amps, not including losses and efficiency etc) but the only way it makes sense is if it breaks down into separate circuits inside the inverter and so each circuit carries less amps.
On a different forum I kind of got that answer that it's multiple circuits and was also told it is highly unlikely to be in parallel but when I looked up multiple fuses in series it seems like that doesn't mean a higher amp rating and isn't really done in practice either.
So I've not had a simple explanation, maybe it's too technical to explain?
Most the information pages I've read though would make you think the dc input can be calculated by watts divided by volts so should technically have a fuse to match.
No where can I find an answer and have noticed car audio amplifiers have multiple fuses too but it shed no light shed searching regarding those either.
Cheers.
For the 1000watt one (1000 continuous/2000 peak) you'd expect a fuse of at least 80 amps or more for dc input side (1000w ÷ 12v = 83amps, not including losses and efficiency etc) but the only way it makes sense is if it breaks down into separate circuits inside the inverter and so each circuit carries less amps.
On a different forum I kind of got that answer that it's multiple circuits and was also told it is highly unlikely to be in parallel but when I looked up multiple fuses in series it seems like that doesn't mean a higher amp rating and isn't really done in practice either.
So I've not had a simple explanation, maybe it's too technical to explain?
Most the information pages I've read though would make you think the dc input can be calculated by watts divided by volts so should technically have a fuse to match.
No where can I find an answer and have noticed car audio amplifiers have multiple fuses too but it shed no light shed searching regarding those either.
Cheers.
It's not really my area of expertise but....
it's quite plausible that different areas of the 'mains voltage' output cycle are generated by different circuits within the inverter.
It can be better to have separate smaller fuses, because a fuse can take a long time to blow if the current is only a bit above the rating.
A 10A fuse might be spec'd to carry 20A for a second without blowing, and to blow within a few milliseconds at 40A.
And if you short something in the circuit, the battery and cable resistance will limit the current. It's quite hard to blow a 200A fuse with 12V, a 200A arc is massive and will drop more than 12V. The battery volts might drop to 10 or less, the cables will drop a volt maybe.
So compartmentalising the circuit and fusing each bit at 50A might make a lot of sense.
As for audio amps, there's a saying about the transistors blowing to protect the fuses.....
it's quite plausible that different areas of the 'mains voltage' output cycle are generated by different circuits within the inverter.
It can be better to have separate smaller fuses, because a fuse can take a long time to blow if the current is only a bit above the rating.
A 10A fuse might be spec'd to carry 20A for a second without blowing, and to blow within a few milliseconds at 40A.
And if you short something in the circuit, the battery and cable resistance will limit the current. It's quite hard to blow a 200A fuse with 12V, a 200A arc is massive and will drop more than 12V. The battery volts might drop to 10 or less, the cables will drop a volt maybe.
So compartmentalising the circuit and fusing each bit at 50A might make a lot of sense.
As for audio amps, there's a saying about the transistors blowing to protect the fuses.....
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