240V vs 120V Pros and Cons

M

mannyman

2[H]4U
Joined
Jan 12, 2011
Messages
2,854
I read somewhere that running a computer PSU on a 240v Circuit Will give you better efficiency and reduce waste heat and possibly prolong the lifespan of your PSU.

So i pose the question to those with more knowledge on the situation than I, What are the pros and cans for running the PSU on a 240 vs a 120.
 
The main upside is lower currents which translates to lower losses, also with large PSUs (1KW+) the lower input current is going to significantly reduce the chance of a burnt out AC input connector.

The main downside is that you have to be very careful what you connect once you introduce multiple voltages, newer computer gear is generally fine but older gear may only be single voltage and/or require manual switching.

Another important consideration is making sure the overcurent protection is appropriate. PC PSUs and their power cords are intended to be connected to 15-20 amp circuits, many 240V circuits in the USA have breakers that are considerablly higher than this and if using such a circuit I would strongly suggest downrating the breaker.
 
plugwash said:
The main upside is lower currents which translates to lower losses, also with large PSUs (1KW+) the lower input current is going to significantly reduce the chance of a burnt out AC input connector.

The main downside is that you have to be very careful what you connect once you introduce multiple voltages, newer computer gear is generally fine but older gear may only be single voltage and/or require manual switching.

Another important consideration is making sure the overcurent protection is appropriate. PC PSUs and their power cords are intended to be connected to 15-20 amp circuits, many 240V circuits in the USA have breakers that are considerablly higher than this and if using such a circuit I would strongly suggest downrating the breaker.
Click to expand...

I see, That clears it up a bit.

I think they where talking about running a 240v circuit just for the computer and putting a 20A breaker on it.
 
Generally, running 240v is better for power supplies in terms of efficiency, as has been proven on HardOCP multiple times. The main problem as was stated is making sure not to plug any 120v things into a 240v outlet, as that may potentially lead to some disastrous consequences. Additionally, most households only have 120v outlets, with 240v outlets reserved for large appliances like dryers, so there's that logistical problem of putting 240v outlets where there were none.
 
You could do it but I'm not sure it would be worth the cost of running a separate line just for the pc. We got a couple 240v lines in our house but its all for big stuff like welders / electric stove/ A/C.

The only significant pro I could see is better efficiency. The cons to me would be that you have to be careful of what gets plugged in and cost of installing the outlet. I personally just don't think the cost would be worth it. (If this is a fully completed house, if the house is under construction it would be pretty much the cost of the wire and the outlet and minimal labor since the walls are all open so it's not really a big deal then).
 
Pros: more efficiency due to lower conversion losses.
Cons: none.
 
You could do it but I'm not sure it would be worth the cost of running a separate line just for the pc.
Click to expand...
On the other hand if you already have a circuit dedicated to your computer setup and the insulation is sufficiant (I think standard american cable is insulated for 240V but i'm not positive) changing it from a 120V circuit to a 240V circuit will double it's capacity without any need to increase the cable size.

If you are going down the 240V route one thing I would suggest doing is getting (or making since IEC cords in unusual colors are hard to come by and you will be wiring the plug end yourself anyway to get the 240V plug) some IEC leads in an unusual color and fitting your 240V plugs to them (you should certainly use proper 240V sockets on the wall). That way you have a visual cue that you are about to connect 240V to a peice of equipment.
 
Last edited:
One downside is that you can't put it on a UPS or surge bar. At least not an affordable one.

Also as mentioned, the danger of accidentally plugging in the wrong equipment as the power cord end will be the same, just the part that plugs into the wall that will be different. But you could do as suggested and use a different color cord. Keep a standard, like use a red sharpie to mark the end red or something.
 
You must log in or register to reply here.
Back
Top