HB3 & HN3 Series 
The HB3 and HN3 series vacuum contactors are the smallest and lightest weight of Ross Engineering's high voltage three-phase contactors.  Their 2-cycle total dropout and interrupt time and their level of current and voltage ratings make them ideal for moderate power, high voltage loads such as electronic rectifiers or other medium-size power supplies or industrial loads with 1 to 400 amp, 2.5 to 15KV, 50/60Hz input levels.  Both units, in many applications are built directly into oil-filled rectifier transformers as the primary or secondary control unit.  Its light weight allows it to be mounted in the transformer or supply cabinets without excessive foundation requirements.  Two SPDT form C auxiliary contacts rated 15A, 480V AC are standard and up to four are optional; 10A, 125V DC auxiliaries are also available.  Single-pole and two-pole units are available as well as units for voltages up to 300KV.

HN3 Low Profile