Pump lift stations often use two pumps in order to manage peak periods of waste in-flow. Duplexing is a combination of alternating and lead-lag pump control functions designed to maximize pump life. During each empty cycle, EchoSwitch will alternate the primary pump actuation between relays 1 and 2. If the level rises to the backup set point, then both pumps will be energized simultaneously to empty the sump. It's duplexing made simple!