I am using these motor run capcitors. The are marked 450 VAC, and I have been using a couple of them for about two months without any problem. I am puzzled by the fact that somebody felt the need to use a red and a black wire for the leads instead of two wires the same color. It is clearly not a polarized capacitor.



My question is: Does anybody knows the significance of the color coding?

 

Don't laugh because I know this is true for a manufacturer I used to work for.
Factory buys 2 rolls of cable, one black, one red. They need 100mm of red and 100mm of black for one part they make. They then start to make a second part (the cap in this case). if they use only black wire, they will be left with a unequal amount of red.

I know this sounds stupid, and I hear you say "just buy more black", but when profits are as tight, things like this start to matter.

 

In some cases black indicates the outer foil connection for application where one side is at ground potential.
Max.

 

In the oil filled run capacitors, one lead has an internal fuse. It is usually marked with a red dot, but a red wire would give me the same information.

This probably does not apply to a metalized film capacitor.

 

Who's going to ask, should I cut the black wire or the black wire?