The HEH100PB is a DC 48V rack-mount heater designed for warming air in equipment cabinets to prevent damage from low-temperature conditions. It features dual heating capacity with selectable 500W or 1000W output, operating at a rated voltage of 48 VDC with an operating voltage range of 46–56 VDC. The heater incorporates a PTC heating element with automatic temperature-based control: at intake temperatures below 10°C, it activates at low output (~500W), and below 5°C, it switches to high output (~1000W). The unit includes integrated fan operation, dry contact alarming (60 VDC/400 mA capability), LED status indicators, and a test button for functionality verification. It is available in two mounting configurations: 483 mm (19") and 584 mm (23") rack widths, with dimensions of 44 × 483 × 177 mm or 44 × 584 × 177 mm respectively. The heater provides reliable thermal management for data center and cabinet applications with lower voltage protection that disables operation below 45 VDC to prevent battery drain during power failures.