These upgraded dual-traction models deliver 4600hp in DC mode and 5000hp in AC mode, and were jointly developed by RDSO and BHEL in 1997. Components are shared with the WCAG-1 locos (see below). Co-Co fabricated bogies (High-Adhesion — shared with WCAG-1, WAG-7, WDG-2, etc.) with secondary suspension.
Monocoque underframe. Air brakes are original equipment. They were originally manufactured under a BOLT (build-own-lease-transfer) contract with BHEL, and are probably still owned by BHEL rather than by IR.
Monologue under frame. Axle-hung, nose-suspended, force ventilated, taper roller bearings Speed control by tap changers in AC mode and resistance notching in DC mode. Motors can be placed in different series-parallel combinations. Auxiliaries from Elgi, S F India, Best, Gresham & Craven, etc. Static converter from ACEC for auxiliary supply.
In DC mode, rheostatic braking by self-excitation of traction motors available until 17km/h. compressor, other auxiliaries from S F India. Rated for 105km/h in both DC and AC mode (sometimes AC mode rated speed is quoted at 110km/h). Traction motor configurations as in the WCAM-1/2 and WAM-4 (all 6 in series, 2S 3P, or all parallel — the latter is the only one used under AC traction, enforced now by modifications to the locos).
CR uses WCAM-3 locos on Mumbai-Pune and Mumbai-Igatpuri sections which have ghat portions as well as speed restrictions of about 100km/h. Freight rakes double-headed by WCAM-3 (upgraded models) have been sighted on the ghat sections. For excellent WCAM-3 sightings and regular double-header WDM-2 tanker trains, the Kurla-Vidyavihar section is ideal.
MU operation possible with 3 (4?) units.
Some WCAM-3 locos now [2004] are certified only for DC operation for various reasons, although it is possible they will be fixed and returned to full dual-traction service after repairs. As of [12/05], all WCAM-3 locos had been retrofitted with roof-mounted rheostatic braking grids.
Manufacturers : BHEL
Weight : 121t
Traction Motors : Hitachi HS15250A. Axle-hung, nose-suspended, force-ventilated.
Transformer : BHEL 5400 kVA. 32 taps.
Rectifiers : Two silicon rectifier units D1800N44 (Siemens), 16 cells per bridge. 1000V / 3600A.
Gear Ratio : 64:18
Pantographs : Stone India, AM-12 (AC), AM-18 B2 (DC)
Length : 20950mm
Total wheelbase : 15698mm
Weight : 113t
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