Mr Sandman wrote:


I have an aircon unit that failed. Fault code 'PU' says the capacitor
charging circuit failed, this is confirmed by checking the voltage at the
three large electrolytic caps which show 43vdc, but oddly 85v ac. The
expected voltage at the capacitors should be 180-380vac.


** Gobbledgook.

Large electros acquire *DC voltage* after being charged.

What sort of multimeter / voltmeter are you using ??

An old moving coil one by any chance - many of the latter read double voltage on the AC ranges compared to the DC ranges if mistakenly used for DC.

Reverse the probes and the reading drops to zero.



.... Phil