Voltage is maximum working voltage that the capacitor can withstand. It needs to be equal or higher than the voltage specified by Philips. It is not the actual circuit voltage, so its perfectly adequate for the job.
180W SOX is too bright to look at close up when fully warmed up.Thank you for the advice.
Btw, I've got a few 18W ballast for two foot fluorescent lamp to run the 18W SOX-E lamps, since the small one runs really hot after like 10 minutes of operation, I've decided to source for different one, here there is
I don't have a meter to test at the moment but the long one above with red etch is 0.36A that's as close as one can match 18W SOX running current, it also solve the heat issues as after running it for hours it only get warm that you could still touch the ballast without burning your hand. My question is why is the size difference although having the same spec and power ratings?
The smallest one gets the hottest running temperature, with only 10 minutes of running it gets too hot to be touched, and it fills the room with burn smells so I decided to add a heatsink with a small fan on top of it but it's still gets way too hot. But the larger one seems to be able to handle the lamp and doesn't get hot.
I also connect the ballast to a 70W Philips classic halogen lamp and the small ballast and the Philips medium size ballast at the middle seems to light the lamp up to the same level of brightness, but the longest one ballast above light up the lamp about 20% brighter? Other test are I hooked up the ballast to a 70W son lamp with build in ignitor, the smallest ballast has been able to start the lamp with just a few clicks, Everytime. But the bigger 18W ballasts has failed at every attempts as the glow starter inside the lamp keep on clicking but the arc wouldn't established.
Is there a possibility that I am overdriving the SOX with that large size 18W fluorescent ballast?