How is a Sentinel different from a UPS?
As its name implies an Un-interruptable Power Supplies or UPS means that even if the grid goes down the load will see no interruption in the flow of power. In a UPS, power always flows from the grid, into the batteries, into an inverter and then into the load connected to it. In a Sentinel Mate or Large Sentinel, power usually flows from the grid electric supply directly into the loads attached to it and the Sentinel uses small amounts of power to keep its batteries charged. When there is a blackout the Sentinel detects it and switches the loads so that they are connected to the inverter and batteries instead of the gird. This leads to a small 16 millisecond blip in the supply of power to the loads which is short enough not to affect most household or office appliances but too long to be acceptable for really sensitive electronic equipment like computer servers.
