What AMP fuse for a 1200W PSU?

Space Monkey

Space Monkey

Space Monkey

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Hi guys,

I have an Enermax MaxRevo 1200W PSU and it came with a foreign kettle lead, and the only spare cable I have to hand is a 3 AMP fused lead, and from some basic research it seems this isn't enough?

Should I be looking at a 13A fused kettle lead? Can anyone recommend a really decent made one at all?

Thanks :)
 
Indeed. Ohms law. Cunningly enough the answer is 5. ;)

That said the PCs at work with 300W PSUs ship with a 10A mains lead. Make of that what you will.
 
Watts = Amps x Volts

So 1200W = ?A * 230V, divide 1200 by 230 and you get 5.2, so if they PSU was actually doing 1200W then it would draw 5.2A, however as it will never be maxxed out like that 5A will be enough as people have said.
 
The PSU is 80 Plus Gold certified meaning at 100% load it's ~88% efficient.

If it was outputting at 100% load it would be drawing ~1364 watts from the mains so nearly 6 amps.
 
Lazder said:
Why do you need 1200W PSu these days??? :/
sorry for off-topic.. just intresting
Click to expand...

Was looking for a decent 850w but got this at the same price, rrp is around £230 normally :cool:

Got a single card for now but have a full watercooling setup and an X79 build, will be looking for SLI at some point to :)

••• So at full load I'm looking at 6A, should I still get a 5A or would a 13A be a better choice? Can any of you with high end PSUs tell me what yours came shipped with please just to see what the manufacturers do?

Thanks for all the answers guys, appreciate it :)
 
Just to add a little diversion into the mix... The fuse is there to protect the cable as opposed the device on the end of it. That's why you see very low power consumption devices with high rated fuses.

To run a device at 1200W would need a 5A fuse minimum. Not sure what your application is and whether you would come close to seeing 1200W or if that is the max actual output taking lossess into account etc. There would be no problem at all going with a 7A or higher.

** Edit ** Just checked a few places for you and it seems in general that new leads are rated for 10A and either come with a 10A fuse or 5A fuse. Either will be fine in your application.

Mike
 
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I'd agree, 10A or 7A.... I wouldn't want to be operating "at the threshold" of my 5A fuse rating, you wouldn't want it popping in a non-fault scenario under heavy load with all HDDs spinning etc.

For a fault scenario such as a short circuit, the PSU would be toast anyway whether it was able to draw more power via a higher rated fuse or not. As mentioned, the fuse is there to protect the cable from melting.
 
Get more than a 5A fuse. 7A or 10A will do.
As said, given the efficiency of the PSU you will be drawing more power from the wall than what's being delivered to your components. So at maximum load you will be drawing easily more than 5 amps.
 
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