Schaefer Inc. (Ashland, MA) recently introduced a new series of 800VA to 10kVA, 6U high by 21TE wide Static Switches. The Static Switch is designed to transfer the ac load from the mains to an inverter output or vice versa. It synchronizes the inverter to the mains frequency when mains voltage is present or when it returns after a mains failure. The Static Switch is also designed to monitor input over- and under-voltage of the utility power and also the inverter, short circuit on the output and present mode as well as alarms/faults. There are also individual select inputs for priority and output on and off via optocouplers. A front panel manual switch can also override the automatic selection and connects the load to either the utility power or the inverter. LEDs and potential free relay contacts indicate the mode of operation. Synchronization techniques are used between the inputs which allows for an interruption of only 1/4 of a cycle. The Static Switch is available for 115Vac or 230Vac operation at frequencies from 50Hz to 400Hz with power capabilities from 800VA to 10kVA. Operating temperatures available include -20 degrees C and extended range -40 degrees C to +75 degrees C. The Static Switch is packaged in a 6U chassis and incorporates industry standard DIN 41612 connectors as its wiring interface. According to Schaefer, typical applications include mission critical UPS applications, battery backup for communications equipment, network systems, telecommunication systems, process control systems and power stations.