how to safely deenergize capacitor
I need to replace a ac compressor capacitor and was wondering how to safely deenergize it?also how do itest it after to make sure it is deenergized.I do not like getting shocked!
Forum Discussion
Bob Landry wrote:
Two pages of bad information has certainly made for an interesting read. The capacitors in an AC unit, start, run, and fan, are non-polarized and are not going to hold a charge. These are not power supply filter capacitors. It is also impossible for a capacitor to "recharge" itself if it is not connected to anything.
Speaking of bad information, just because it is non-polarized does not mean it can't retain a charge. Absolutely wrong! More bad information, capacitors CAN accumulate charge, though internal leakage usually keeps it in check. Ever hear of static electricity? As someone who is not only an electrical engineer but once shocked myself off the same television high voltage power supply which was discharged and safely handled before I started working on it, I can vouch for that. It certainly wasn't discharged when I was putting the high voltage rectifier tube socket back in.
Run capacitors *should* discharge themselves through the run windings and secondary windings because they are all in series, so if the power is removed they will be discharged. Start capacitors *should* be discharged in the same way if the centrifugal switch is working properly. Still, Westend's idea of using a light bulb to make sure they are discharged is safer than using a screwdriver. Oh sure, everyone's got an anecdote that it's okay, but exceeding the current rating in that instant still isn't good for it.
