[TowerTalk] Polarized Electrolytic in Rotator Box?

[Jim Lux]

At 03:50 PM 6/29/2007, Clint Talmadge wrote:
>I am glad this thread started. I have  a Motor Start Capacitor ready 
>to be installed at the base of my tower which is marked 130-156 MFD 
>330VAC . How can I tell if it is polarized or not? There are no + or 
>- marks on the terminals and I assumed (I know, I know) that it would work.

It will work.  Motor Start Caps are designed for AC, hence unpolarized.

What they won't work for is a continuous duty application (like power 
factor correction or in a splitphase motor), because they're pretty 
lossy, and they get hot.  In a rotator application, they run for a 
few seconds and stop, so you're ok.

If you need continuous duty, you need "motor run" caps, which are 
much larger and expensive for the same capacitance.