A UPS differs from an auxiliary or emergency power system or standby generator as it provides near-instantaneous protection from input power interruptions. It does this by supplying energy stored in_____________, super capacitors, or flywheels.

What else do most UPS do in addition to providing protection from loss of power supply?

_______________ the load is powered directly by the input power and the backup power circuitry is only used when the supply power fails. Most UPS below 1 kVA are of the line-interactive or standby type and are usually less expensive.

________________maintains the inverter in line and redirects the battery’s DC current path from the normal charging mode to supplying current when power is lost.

_______________- takes AC input, rectifying to DC for passing through the rechargeable battery, then inverting back to 120V/240V AC for powering the protected equipment.

For large power units, ________________________are often used.

There are primarily __________kinds of batteries used in UPSs.

________________________, also known as sealed or maintenance-free.

______________ (also called flooded-cell).

___________ are sealed, usually within polypropylene plastic. They have the advantage of containing no liquid that might leak or drip out when inverted or handled roughly.

VRLA batteries usually have lower up-front costs but have a ___________than wet-cell, usually around five years.

Wet-cell/flooded-cell batteries have thick lead-based plates that are flooded with an acid electrolyte. Failures normally don’t occur until halfway through their _________pro-rated life.

Wet-cells require ___________and a space-consuming separate battery room to use. Wet-cell batteries also require more advanced maintenance.