Bonitron Short Term Sag Solutions, including the M3534R and M3460R, solve nearly 95% of power quality events. There is no energy storage so the unit is smaller and costs less than traditional UPS systems. Bonitron M3534R and M3460R Modules are for 3-phase sags and require virtually no maintenance. The Voltage Regulators regulate the DC bus during a voltage sag. As the incoming voltage level drops, the Voltage Regulator boosts the rectified DC current up to the level needed by the drive.