Executive Overview
The DIN rail is a standardized metal mounting rail widely used for mounting circuit breakers, terminal blocks, PLCs, relays, and switching power supplies inside industrial equipment racks and electrical control cabinets. Originally standardized by the Deutsches Institut für Normung (DIN) and now codified internationally under EN 60715 and IEC 60715, the 35mm wide top-hat rail (TS-35) is the global benchmark for industrial automation.
TS-35 Rail Geometry: 35/7.5 vs. 35/15
TS-35 rails feature a symmetrical top-hat cross-section measuring exactly 35mm across the outer flanges. Two depth profiles dominate industrial installations:
- ●TS-35 / 7.5: 35mm wide by 7.5mm deep, typically manufactured from zinc-plated cold-rolled steel or extruded aluminum. Standard for low-to-medium weight components up to 100W.
- ●TS-35 / 15: 35mm wide by 15mm deep with enhanced section modulus. Required for heavy industrial power supplies (240W to 480W) to prevent rail bowing or deflection under vibration.
Thermal Layout & Chimney-Effect Airflow Rules
Unlike open-frame chassis mounted on flat baseplates, DIN rail power supplies utilize natural chimney-effect vertical convection. Cool ambient air enters through bottom ventilation slots, passes across internal magnetic transformers and semiconductors, and vents through top grilles.
For reliable 24/7 continuous operation, always observe minimum keep-out spacing rules: leave at least 20mm–40mm of clearance above and below the power supply, and 5mm–10mm of lateral clearance between adjacent electrical components.
- ✓Standardized 35mm top-hat profile (EN 60715) eliminates manual drilling and baseplate screw fastening.
- ✓Ultra-slim DIN power supplies (e.g., 32mm–40mm NDR/EDR) save up to 40% horizontal rail space.
- ✓Vertical convection chimney airflow demands vertical mounting and proper top/bottom clearance.