C.E. Niehoff & Co.
C510 and C540 Alternators
Troubleshooting Guide
Hazard Defi nitions
These terms are used to bring attention to presence of hazards of
various risk levels or to important information concerning product
life.
Indicates presence of hazards that
CAUTION
will or can cause minor personal
injury or property damage.
Indicates special instructions on
NOTICE
installation, operation or mainte nance that are important but not
related to personal injury hazards.
Table of Contents
Section A: C510 Wiring Diagrams ............................2
Section B: C540 Wiring Diagrams ............................3
Section C: Basic Troubleshooting .............................4
Section B: Advanced Troubleshooting ............... 5 – 7
Battery Conditions
Until temperatures of electrical
NOTICE
system components stabilize, these
conditions may be observed during
cold-start voltage tests.
• Maintenance/Low Maintenance Battery
— Immediately after engine starts, system volts are
lower than regulator setpoint, amps are medium.
— 3–5 minutes into charge cycle, system volts increase,
amps decrease.
— 5–10 minutes into charge cycle, system volts
increase to, or near, regulator setpoint and amps
decrease to a minimum.
— Low maintenance battery has same characteristics
with slightly longer recharge times.
• Maintenance-free Battery
— Immediately after engine starts, system volts are
lower than regulator setpoint, low charging amps.
— Once charge cycle begins, low volts and low amps
are still present.
— After alternator energizes, voltage will increase
several tenths. Amps will increase gradually, then
quickly, to medium to high amps.
— F i n a l l y , v o l t s w i l l i n c r e a s e t o s e t p o i n t a n d a m p s w i l l
decrease.
The time it takes to reach optimum voltage and amperage will vary with engine speed, load, and ambient
temperature.
• High-cycle Maintenance-free Battery
These batteries respond better than standard maintenance-free. Charge acceptance of these batteries may
display characteristics similar to maintenance batteries.
• AGM (Absorbed Glass Mat) Maintenance-free Batter y
These dry-cell batteries respond better than standard
maintenance-free. If battery state of charge drops to
75% or less, batteries should be recharged to 95% or
higher separately from the engine’s charging system to
avoid damaging charging system components and to
provide best overall performance. Charge acceptance of
these batteries may display
maintenance batteries.
characteristics similar to
Battery Charge Volt and Amp Values
Volt and amp levels fluctuate depending on the battery state
of charge. If batteries are in a state of discharge—as after
extended cranking time to start the engine—system volts
will measure lower than the regulator setpoint after the
engine is restarted and system amps will measure higher.
This is a normal condition for the charging system; the
greater the battery discharge level, the lower the system
volts and the higher the system amps. The volt and amp
readings will change as batteries recover and become fully
charged: system volts will increase to regulator setpoint
and system amps will decrease to low level (depending on
other loads).
• Low Amps: Minimum or lowest charging system amp
value required to maintain battery state of charge,
obtained when testing the charging system with a fully
charged battery and no other loads applied. This value
will vary with battery type.
• Medium Amps: System amps value which can cause
the battery temperature to rise above adequate charging
temperature within 4-8 hours of charge time. To prevent battery damage, the charge amps should be
reduced when battery temperature rises. Check battery
manufacturer’s recommendations for proper charge
amp rates.
• High Amps: System amps value which can cause
the battery temperature to rise above adequate charging
temperature within 2-3 hours of charge time. To prevent battery damage, the charge amps should be
reduced when battery temperature rises. Check battery
manufacturer’s recommendations for proper charge
amp rates.
• Battery Voltage: Steady-state voltage value as mea-
sured with battery in open circuit with no battery load.
This value relates to battery state of charge.
• Charge Voltage: Voltage value obtained when the
charging system is operating. This value will be higher
than battery voltage and must never exceed the regulator voltage setpoint.
• B+ Voltage: Voltage value obtained when measuring
voltage at battery positive terminal or alternator B+
terminal.
• Surface Charge: Higher than normal battery voltage
occurring when the battery is disconnected from
battery charger. The surface charge must be removed
to determine true battery voltage and state of charge.
• Significant Magnetism: Change in strength or inten-
sity of a magnetic field present in alternator rotor shaft
when the field coil is energized. The magnetic field
strength when the field coil is energized should feel
stronger than when the field is not energized.
• Voltage Droop or Sag: Normal condition occurring
when the load demand on alternator is greater than
rated alternator output at given rotor shaft RPM.
TG1B
Page 1
Section A: C510 Wiring Diagrams
CEN C510 Alternator
Description and Operation
C510 14 V (280 A) 3-phase brushless alternator uses an
externally mounted rectifier and regulator. All windings
and current-transmitting components are non-moving,
so there are no brushes or slip rings to wear out. This
unit is externally energized through an energize switch,
which activates regulator. Field coil is then energized.
Regulator maintains alternator output voltage at regulated setting as vehicle electrical loads are switched on
and off. Alternator output current is self-limiting and
will not exceed rated capacity of alternator.
A2-136 external regulator furnished with all units has
R terminal for optional AC voltage tap. Optional 15.5 V
regulator setpoint is available for battery isolator applications.
A8-201 or A8-205 external rectifier allows for mounting in engine compartment. A8-205 rectifier suppresses
electromagnetic interference (EMI) with internal filters
to acceptable levels defined by the Society of Automotive
Engineers (SAE) specification J1113/41. A8-205 rectifier
will not reduce EMI from sources such as antennas,
poor cable routing practice, or other electronic devices
that cause EMI. If EMI continues, consult an electromagnetic compliance (EMC) specialist to determine EMI
source.
R
BK
W
G
Figure 1 — C510 Wiring Diagram
Page 2
Figure 2 — C510 Terminal Locations
TG1B
CEN C540 Alternator
Description and Operation
C540 14 V (300 A) 3-phase brushless alternator uses an
externally mounted rectifier and regulator. All windings
and current-transmitting components are non-moving,
so there are no brushes or slip rings to wear out. This
units is externally energized through an energize switch,
which activates regulator. Field coil is then energized.
Regulator maintains alternator output voltage at regulated setting as vehicle electrical loads are switched on
and off. Alternator output current is self-limiting and
will not exceed rated capacity of alternator.
A2-136 external regulator furnished with all units has
R terminal for optional AC voltage tap. Optional 15.5 V
regulator setpoint is available for battery isolator applications.
A8-205 external rectifier allows for mounting in engine
compartment. A8-205 rectifier suppresses electromagnetic interference (EMI) with internal filters to acceptable
levels defined by the Society of Automotive Engineers
(SAE) specification J1113/41. A8-205 rectifier will not
reduce EMI from sources such as antennas, poor cable
routing practice, or other electronic devices that cause
EMI. If EMI continues, consult an electromagnetic compliance (EMC) specialist to determine EMI source.
Section B: C540 Wiring Diagrams
R
BK
W
G
Figure 3 — C540 Wiring Diagram
Phase
cable
P and IGN terminal nuts –
torque to 3.4 Nm/30 lb. in.
Alternator
Regulator
Cable bracket
LOC. B
Cable bracket
LOC. A
Field inline connection
P
IGN
B+
(see
inset above)
Screws –
torque to 6.7 Nm/60 lb. in.
Cable bracket
LOC. C
Field
inline
connection
Rectifi er
Washer
B+ terminal bolt –
torque to 30 Nm/22 lb. ft.
Lockwasher
Battery output cable terminal
B+ Terminal Connection
Phase terminal bolts (3 places) –
torque to 8 Nm/70 lb. in.
B– terminal bolt –
torque to 30 Nm/22 lb. ft.
Insulator
TG1B
Figure 4 — C540 Terminal Locations
Page 3