Can anyone tell me how to test and charge the capacitor in the control box for my submersible water pump?

I have a 220v, 3/4 hp submersible well i just installed a little while back. Also installed a control box of the right specifications for it. Both are used however. After the initial installation, I didnt have the pressure tank hooked up yet, so i just closed the main shut off valve and turned the power on to it for a couple seconds to see if it would come on. It did. So I shut it off until I got the pressure tank installed and everything hooked back up a couple weeks later. I then tried to turn it on and nothing happened. I put a voltmeter on the capacitor and it showed a reading, but that reading was less than the chart on the inside of the box stated that it required. I verified that I was getting power through the pressure switch and coming into the box. It actually read almost 260v instead of 220. I dont have a capacitor tester. Can someone please tell me how I can go about testing it and tell me how to charge it correctly before putting it back in the circuit? I'd appreciate it