Buying a Longer Power Cord

[WPCentral Question]

I bought a longer power cord for my Surface Pro 3 power adapter, the cable that goes from the outlet to the brick, the new cable says 2.5A 250V on it and is 22 awg but the power adapter says it takes an input of 1A... does any of this matter or is it safe to plug in any cable that fits into the power adapter?

 

[eusty]

There are a lot factors which affect a current rating of a cable (insulation type, grouping, ambient temperature etc) but a 22awa cable should take 3 amps comfortably.

 

[Harrie-S]

2.5A 250V means that this cable can support up to 2.5 A and because the power adapter only "needs" 1 A it's safe to use the new cable.

If it was the other way around so the adapter"needs" 2.5 A and the cable was rated 1A then you are in trouble because in this situation the cable would overheat because too much current is forced to go through the cable and it may melt.

Now basically it is safe to plug any cable which fits as long as the cable is rated "higher" that the adapter.

So you can also compare A (current) with water pressure. Fire engines have "big" water hoses so so they can handle high water pressure (high current) but if you would connect your garden hose to it your garden hose would "explode" because it can not handle the water pressure.

 

[eusty]

but if you would connect your garden hose to it your garden hose would "explode" because it can not handle the water pressure.

Although cables melt rather than explode!

The hose analogy isn't particularly true though, voltage could be compared to 'pressure', but current is closer related to the 'flow'

 

[Harrie-S]

Although cables melt rather than explode!

The hose analogy isn't particularly true though, voltage could be compared to 'pressure', but current is closer related to the 'flow'

True but i wanted it to make it clear (as simple as possible) that using the new cable was no problem at all.