Measuring voltage in a 440 V motor start capacitor
Motor start capacitors are only used on AC motors and there will be an AC voltage across it.


To measure the voltage across the capacitor use a multimeter or voltmeter with a 1000 V safety rating. 
Switch the meter to the next AC range higher than 440 V.
Connect the probes safely to the capacitor with the power switched off.
Stand back, switch on, take the readings and switch off before disconnecting.


Do not try this with a $5 meter. Both meter and probes need to be adequately rated with a recognised safety mark.