Thermo King KD-II SR, Manual

Page: 68 / 182

Electrical Maintenance (Rev. 04/03)
54
As the motor approaches normal running speed, the current
through T2-T2A drops. When this current drops below 22
amps, the current relay is de-energized. This de-energizes
the motor start relay, the motor start contactor and the start
capacitors. The start system is now disconnected from the
motor circuit and the run system provides the phase shift
necessary to operate the motor at normal running speed.
Third Phase Connection During a Start
L2 supplies power to the third windings in
both sets of motor windings through the start
second windings in both sets of windings in the motor
Run System
The components of the run system are:
• a run transformer
• two run capacitors (60
µ
F each)
• two run bleed down resistors (560 k ohms each)