Sutton's Locomotive Workshop British Railways Sulzer Type 2 Operating Manual - page 9
BTH Electrical Equipment
Generator and Auxiliary Machines
The generator unit comprises three machines – a main generator, an auxiliary
generator and a differential exciter. The main generator is a single-bearing, 12-pole,
separately-excited, self-ventilated machine solidly coupled to the diesel engine and
mounted on an extension of the engine underbed. It is a 735 kW machine rated at
750/525 Volts, 980/1400 Amps, 750 rpm. The armature is built on a fabricated
cylinder, a stub shaft being provided at the bearing end. The drive from the engine
is taken on the full diameter of the cylinder, ensuring great torsional rigidity and
freedom from the effect of cyclic variation of torque. The BTH ‘Pollock Type’
commutator construction is used which obviates the possibility of loosening of
segments in service.
The brushes are split in pairs with equalised pressure on each brush. Pressure is
applied through an insulated roller so that it is impossible for the brush arms to
carry current from the top of the brush. Brush pressure is adjustable and compensated
between the two half brushes.
The auxiliary generator is an 8-pole, separately-excited, constant-voltage
machine of 50 kW, 110 Volts, 500/750 rpm; the armature is mounted on an extension
of the shaft of the main generator. In order to reduce the length of the set to a
minimum, the auxiliary generator is accommodated partly within a recess in the
main generator commutator.
The exciter is a 4-pole machine with separate, self and differential series excitation
windings. It is mounted upon an adjustable platform on top of the auxiliary generator
frame, and is belt-driven from the main generator shaft extension. The output of the
exciter is controlled by the engine load regulator.
Traction Motors
The four nose-suspended, series-wound traction motors drive through single-
reduction gearing. Each motor as a one-hour rating of 209 hp, 490 Volts, 375 Amps,
505 rpm and a continuous rating of 213 hp, 525 Volts, 350 Amps, 560 rpm. They
are force ventilated by two separate blowers which are driven by a single 12.2 hp,
110 Volt, 2,600 rpm motor; each blower provides ventilating air to a pair of motors.
The motors are axle hung and nose-suspended by Metalastic chevron rubber
units which whilst providing a soft vertical suspension, effect a large measure of
lateral control of the motor irrespective of side movement of the axle, thus reducing
flange wear and improving the riding of the locomotives. The gear wheels are of
resilient construction, and consist of a hub and toothed rim connected through
rubber bushes which cushion mechanical shocks due to accelerating forces and
track irregularities.
SLW Class 24 Operating Manual
Page 17
Page 16
SLW Class 24 Operating Manual