The Square Dâ„¢ by Schneider Electric brand Heavy Duty Safety Switch is designed to be tough, reliable and provide exceptional performance in the most grueling conditions. This short circuit rating for a non-fusible switches is based upon the Square D circuit breakers or Mag-Gard motor circuit protectors chosen as upstream protection. This device is rated at 400 amps, three poles, 350 horse power, with a voltage of 600 VAC and 600 VDC. This device is Type 3R rated with a galvannealed steel enclosure.