Voltage sags and momentary interruptions plague power quality professionals worldwide. No business can afford the costly production losses that sometimes occur when small control relays de-energize during these events. This was the case for one facility in Marietta, Ohio. The plant, which produces polyvinyl styrene pellets for end-use processing at other facilities, found the control power circuits for its cooling water systems were particularly susceptible to voltage variations. Plant personnel wanted a cost-effective solution that would fit inside their existing control center and avoid the need for an extensive motor control redesign.