POWER SUPPLY CLASSIFICATION :

My search on google for power supply classes led me to upload this here. To my surprise, the search only ended up giving me irrelevant results.

Here are the classes of power supply for you.

Class Power Supply Remark

I Battery Most reliable in the event of a power failure if maintained well.

Provides only DC supply

II UPS Uninterruptible Power Supply, provides AC supply

Next to batteries, most reliable if maintained well

Contains a battery or set of batteries and an inverter

III Diesel Generator Sets More reliable than the power supply from the grid, if maintained well

Takes a few to many seconds to cater to full load from the moment start command is given at the instance of grid power failure

Hence, there is an interruption

IV Grid Supply HT / LT supply provided by the national or regional grid.

Chandru.