How important is balancing?

My homemade 5 HP RPC has (2)-75 Mf run capacitors. There is a very slight growl when there is no load. Silky smooth when anything is switched on. I have used it for several years.

A friend has a larger shop with a 20 HP RPC and a 30 HP RPC. He runs several large machines and an overhead crane. He has operated for years with no run capacitors at all.

I am gathering parts for a 10 HP unit. How important are run capacitors? Should I worry about balancing? Can someone explain "balancing for dummies"? Do I try to balance it unloaded, loaded. Doesn't the load continually change as I use more machines? Am I looking for balance in volts or amps?

SCOTTIE

With good balance, your power consumption will be the lowest and the motors will develop their full HP and will not overheat. So it worth aiming for. The real world problem is that the actual capacitor values can only be optimised for one set of working conditions but a well balanced setup will always be better then one with no capacitors. If you can measuure the actual motor currents, use these values they are at least 5X more sensitive then the corresponding voltage measurements. i.e. a balance of 2% of the currents correspond to a voltage balance of .4%, while a rough and ready voltage match of 10% actually means that the motor currents can be 50% different!
If different motors are used different capacitors should really be switched in unless you are really lucky!!
Frank