Allen‑Bradley 100‑B300ND3 Non‑Reversing Contactor 304A 600V 3 Pole
The Allen‑Bradley 100‑B300ND3 is a heavy‑duty, non‑reversing contactor rated for 304 amperes continuous current at 600 V AC, 50/60 Hz. Designed for motor starting, lighting control, and power switching applications, this 3‑pole contactor provides reliable isolation and switching for loads up to 150 HP at 480 V (NEMA size 5 equivalent). The contactor features a magnet blow‑out design for arc suppression and complies with IEC 60947‑4‑1 and UL 508 standards.
Electrical Ratings
Rated insulation voltage (Ui): 1000 V. Rated impulse withstand voltage (Uimp): 8 kV. AC‑3 duty (motor starting): 304 A at 600 V, making it suitable for squirrel‑cage motors. AC‑1 duty (resistive): 400 A at 600 V. Thermal current (Ith): 400 A. Short‑circuit withstand capability: 50 kA at 600 V when protected with appropriate fuses (Class J or L). The contactor is suitable for 50/60 Hz operation.
Coil and Control Options
The 100‑B300ND3 is supplied with a standard AC magnetic coil. Standard control voltages: 120 V, 208 V, 240 V, 480 V, and 600 V (specify at ordering). The coil inrush power is 450 VA, sealed power 65 VA. Pick‑up voltage: 85% of rated coil voltage, drop‑out voltage: 20‑75%. Coil protection includes transient suppression (varistor or RC snubber) available as an accessory. The contactor can also accept DC coils with added rectifier modules.
Main Contacts and Auxiliary Contacts
Three main contacts are silver‑cadmium oxide alloy, double‑break design. Contact gap is >5 mm when open. Electrical life: 1.2 million operations under AC‑3. Mechanical life: 10 million operations. The contactor comes with one normally open (NO) and one normally closed (NC) auxiliary contact block mounted on the side (rated 10 A at 600 V AC). Additional auxiliary contact blocks (up to 4 modules) can be snap‑on added, offering combinations of NO/NC.
Construction and Mounting
The enclosure is open‑style (IP00) for panel mounting, with an optional IP20 finger‑safe terminal shroud. Dimensions: width 160 mm, height 220 mm, depth 150 mm. Weight 4.2 kg. Terminals accept copper or aluminium cables up to 150 mm² (two per phase). Mounting is via four M5 screws, either horizontal or vertical. The contactor incorporates a manual override button for testing and maintenance.
Environmental and Safety
Operational temperature range: -25 to 60 °C (no derating up to 50 °C). Storage: -40 to 80 °C. The contactor is certified for ex‑environments (class I, division 2) with proper enclosure. It features anti‑welding contacts and a mechanical interlock (if used in reversing configuration, external interlock required). Arc chutes are made of reinforced thermoset plastic with ceramic plates for arc extinguishing.
Applications
Typical uses include motor control centres (MCC), large HVAC compressors, industrial pumps, crushers, and main disconnects for lighting panels. The 100‑B300ND3 is frequently paired with an overload relay (Allen‑Bradley 193‑E series) to form a complete motor starter. Its high continuous current rating also makes it suitable for capacitor switching and transformer energising.
