C.E. Niehoff & Co. C626 Troubleshooting Guides - Manual (Page 2)

Page 2 TG67B
Section A: Wiring Diagrams
B– terminal
P
terminal
T terminal
(A2-337 only)
Figure 2 — C626 Alternator with A2-141 or A2-337 Regulator
Figure 1 — C626 Alternator Terminals
B+ terminal
D+ terminal
CEN C626 Alternators
Description and Operation
C626 28 V (260 A) alternator is 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
A2-337 regulator, the alternator
becomes self-energized through sensing of alternator
rotation through AC circuit. Residual magnetic field
induces small voltage in stator and energizes field coil.
Field coil continues receiving incremental voltage until
full voltage is achieved. Regulator controls voltage out-
put. See wiring diagram, Figure 2. A2-337 regulator
has:
• P terminal that can provide optional AC voltage tap.
• D+ terminal that can provide DC voltage signal to
vehicle electrical system, confirming alternator
operation.
• Tricolored LED. See page 4.
• T terminal to connect optional A9-4011 temperature
sense lead to adjust regulator setpoint to maintain
charge voltage (or negative temperature compensa-
tion) by sensing ambient temperature within the
battery box. If temperature sense lead is not
connected, regulator uses setpoint switch on the
back of the regulator to keep a constant setpoint
(or flat temperature compensation).
When controlled by the A2-141 regulator, this alternator
becomes self-energizing through internal diode trios.
Residual magnetic field induces small voltage in stator
T
(A2-337 only)
LED
(A2-337 only)

and energizes field coil. Field coil continues receiving
incremental voltage until full voltage is achieved. AC is
rectified into DC output through diodes. Regulator con-
trols 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.