Typically referred to as an “ice cube” relay due to its clear plastic cover that resembles a square ice cube, these AC-powered relays may be susceptible to many voltage sags that do not affect other elements of a control system.
Power Quality Solutions Incorporated (PQSI) has successfully developed and had tested by UL/CSA a “NiceCube” design that has proven to be a viable solution to this vexing problem. The NiceCube design offers a simple, elegant, and completely integrated module solution that includes a voltage sag tolerant general purpose DC DPDT relay that allows for the quick, easy replacement of an existing AC DPDT sensitive 24Vac or 120Vac relay for retrofit or new applications. This solution vastly improves the voltage sag ride-through characteristics of previously vulnerable electrical control system circuits such as emergency off circuits (EMO) in semiconductor tools and industrial production lines—with no capacitance incorporated in the design. Therefore, with no time delay for dropout, the NiceCube also finds application in chiller and air compressor controls as well.