Starting with the supply of diodes for traction application, Hirect now caters to wide range of rectifiers for rolling stock application. High power electric locomotive, AC Electrical Multiple Units are powered by Hirect’s on-board or under slung rectifiers. Hirect rectifiers are also installed on board Diesel locomotives and Diesel-Electric Multiple Units. Rectifiers for special purpose like OHE cars, Mobile Maintenance Units, Accidents Relief vans etc. are also catered. On-board Installation and Under-carriage slung version of rectifier sets are manufactured by highly trained work force and specially created infrastructure for a high degree of reliability in critical traction application.
In the early seventies HIRECT began production of complete rectifier assembly for AC electric locomotive. Initial designs were based on Hirect's diode type HFN 350 and the rectifiers were used for WAG–4 and WAM–4 locomotives. Subsequently the rectifiers were built with lesser number of diodes of higher current carrying capacity type S43AR510 and these rectifiers were used for WAG –5 and WAG-7 / WAP-1 locos. HIRECT is presently supplying these rectifiers along with the compact version of the rectifiers which is almost half the size and provides space optimization inside the locomotive.
The Indian Railways operates large number of diesel locomotives and HIRECT has developed a series of rectifiers for diesel locomotives. The basic design and construction is similar to the rectifiers for electric locomotives but the operating conditions are more stringent in terms of fumes and vibration of the diesel engines. These rectifiers are provided with self cooling and are used for WDM-2 and WDG–2 locomotives.
HIRECT has also designed and developed rectifiers which eliminates self cooling system by integrating the rectifier cooling with that of main alternator and is mounted on top of the alternator thereby reducing space requirement. Rectifiers are also supplied for AC-DC locomotives.
HIRECT also supplies rectifiers for main line EMUs (Electric Multiple Units) as well as DEMU (Diesel electric Multiple Units) and DETC (Diesel Electric Train Cars) used for maintenance.