I have a customer that has a piece of electrical equipment that is sensitive to incoming power instabilities. They have installed a capacitor bank for Power Factor correction that will absorb transient fluctuations and minor imbalances.

Question is: If a capacitor bank is sized correctly and controls are in place, can the capacitors sustain operating power to the equipment (for 5-6 seconds) on a power loss or brownout?

We need 5-6 seconds to shut the equipment down safely.

Regards

~Chris

 

Not that long by any stretch, in any case you are dealing with AC so the storage level will depend at the point of switch off.
They do not store an AC reserve to supply AC based equipment.
Max.

 

To provide 5-6 seconds of power you need some form of uninterruptable power supply (UPS). How much power does it have to supply?

 

Not a chance. You can't store AC in a capacitor, no matter how big it is. The best you can do is a few milliseconds. That's enough to absorb transients and minor fluctuations, but it won't run anything. It seems you have a mistaken belief.