Siemens Low Voltage Residential Circuit Breakers Main Breakers - Type QS Breakers are Circuit Protection Load Center Mains, Feeders, and Miniature Circuit Breakers. Type: QS Application: Electrical Distribution Standard: UL 489 Voltage Rating: 120/240V Amperage Rating: 100A Trip Range: Thermal Magnetic Interrupt Rating: 10 AIC Number Of Poles: 2P