C.E. Niehoff & Co. C612/C617/C621/C624 Troubleshooting Guides - Manual (Page 3)

Page 3 TG2D
Section A: Wiring Diagrams
(CONT’D)
CEN C621 Alternator
Description and Operation
C621 28 V (220 A) alternators are self-rectifying and
self-energized. All windings and current-transmitting
components are non-moving, so there are no brushes or
slip rings to wear out.
When controlled by the
A2-141 regulator, these alterna-
tors become self-energizing through internal diode
trios. Residual magnetic field induces small voltage in
stator and energizes field coil. Field coil continues
receiving incremental voltage until full voltage is
achieved. AC is rectified into DC output through diodes.
Regulator controls voltage output. Regulator has:
• D+ terminal to provide a signal to vehicle electrical
system, confirming alternator operation
• P terminal to provide an optional AC voltage tap.
Figure 4 — C621 Alternator Terminals
Figure 5 — C621 Alternator Wiring Diagram
B– Ground Bolt
B+ Terminal
D+ Terminal
R or P Terminal
 


BR
R
BK
G
W