Why do switches have a higher ac than dc rating?

2 ⤊

Why do switches have a higher ac than dc rating?

2007-01-25 07:21:58 · 3 answers · asked by lone wolf 1 in Home & Garden ➔ Maintenance & Repairs

3 answers

AC current changes direction constantly, passing through a zero current point twice per cycle. DC current is constant and steady with no zero crossings.

When you open the circuit, the current will still attempt flow across the opening, creating an arc. During AC operation the arc will be supressed more easily due to the zero current conditions. DC will sustain the arc in a more prolonged manner.

2007-01-25 07:34:55 · answer #1 · answered by Warren914 6 · 1⤊ 0⤋

DC WILL MELT THE SWITCH - EDISON WANTED D/C & DIDN'T KNOW THAT IT WOULD MELT THE POWER LINES!

2007-01-25 08:21:26 · answer #2 · answered by Bonno 6 · 1⤊ 0⤋

Warren914 nailed it for you. He's exactly right.

2007-01-25 07:47:37 · answer #3 · answered by wlm_loh 1 · 0⤊ 0⤋