C.E. Niehoff & Co. C711, C712 Troubleshooting Guides

C. E. Niehoff & Co.

BRUSHLESS ALTERNATORS

700 Series Troubleshooting Guide

for C711/C712 Alternators

Hazard Definitions

These terms are used to bring attention to presence of hazards of various risk levels or to important information concerning product life.

CAUTION

personal injury or property damage if ignored.

NOTICE

maintenance that are important but not related to personal injury hazards.

Indicates presence of hazards that will or can cause minor

Indicates special instructions on installation, operation or

Table of Contents

Section 1: Wiring Diagram ...................................... 2

Section 2: Basic Troubleshooting ............................ 3

Section 3: Advanced Troubleshooting ................4 – 6

Battery Conditions

NOTICE

conditions may be observed during cold start voltage tests.

• Maintenance/low maintenance battery: — Immediately after engine starts, system volts

are lower than regulator setpoint with medium amps.

— 3-5 minutes into charge cycle, higher system

volts and reduced amps.

— 5-10 minutes into charge cycle, system volts

are at, or nearly at, regulator setpoint, and amps are reduced to a minimum.

— Low maintenance battery has same charac-

teristics with slightly longer recharge times.

• Maintenance-free battery: — Immediately after engine start, system volts are

lower than regulator setpoint with low amps.

— 15-30 minutes into charge cycle, still low volts

and low amps.

— 15-30 minutes into charge cycle, volts increase

several tenths. Amps increase gradually, then quickly to medium to high amps.

— 20-35 minutes into charge cycle, volts increase

to setpoint and amps decrease.

• 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.

Until temperatures of electrical system components stabilize, these

Charge Volt and Amp Values

The volt and amp levels are a function of the batterystate of charge. If batteries are in a state of discharge, as after extended cranking time to start the engine, the system volts, when measured after the engine is started will be lower than the regulator set point and the system amps will be high. This is a normal condition for the charging system. The measured

values of system volts and amps will depend on the level of battery discharge, in other words, the greater the battery discharge level the lower the system volts and higher the system amps will be. The volt and amp readings will change and system volts reading will increase up to regulator set point and the system amps will decrease to low level (depending on other loads) as the batteries recover and become fully charged.

Low Amps:Low Amps:

•

Low Amps: A minimum or lowest charging system

Low Amps:Low Amps:

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:Medium Amps:

•

Medium Amps: A system amps value which can

Medium Amps:Medium Amps:

cause the battery temperature to rise above the 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 amps rates.

High Amps:High Amps:

•

High Amps: A system amps value which can cause

High Amps:High Amps:

the battery temperature to rise above adequate charging temperature within 2-3 hours. To prevent battery damage the charge amps should be reduced when the battery temperature rises. Check battery manufacturer’s recommendations for proper charge amp rates.

Battery Voltage:Battery Voltage:

•

Battery Voltage: Steady-state voltage value as

Battery Voltage:Battery Voltage:

measured with battery in open circuit with no battery load. This value relates to battery-state of charge.

Charge Voltage:Charge Voltage:

•

Charge Voltage: A voltage value obtained when

Charge Voltage:Charge Voltage:

the charging system is operating. This value will be higher than battery voltage and must never exceed the regulator voltage set point.

B+ Voltage:B+ Voltage:

•

B+ Voltage: A voltage value obtained when mea-

B+ Voltage:B+ Voltage:

suring voltage at battery positive terminal or alternator B+ terminal.

Surface Charge:Surface Charge:

•

Surface Charge: A higher than normal battery

Surface Charge:Surface Charge:

voltage occurring when the battery is removed from a battery charger. The surface charge must be removed to determine true battery voltage and state of charge.

Significant Magnetism:Significant Magnetism:

•

Significant Magnetism: A change in the strength

Significant Magnetism:Significant Magnetism:

or intensity of a magnetic field present in the 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: Voltage Droop or Sag:

•

Voltage Droop or Sag: A normal condition which

Voltage Droop or Sag: Voltage Droop or Sag:

occurs when the load demand on the alternator is greater than rated alternator output at given rotor shaft RPM.

TG0009A

Page 1

Section 1: Wiring Diagram

CEN C711/C712 Alternators Description and Operation

C711C711

The

C711 alternator (14 V, 360 A)and

C711C711

tor (14 V, 400 A) are internally rectified. All windings and current-transmitting components are nonmoving, so there are no brushes or slip rings to wear out. This unit is externally energized through either an ignition switch or an energize switch (commonly an oil pressure 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.

A2-121 regulator used with all units has a 15.5 V regulator setpoint available for battery isolator applications.

Electromagnetic interference (EMI) is suppressed with internal filters to acceptable levels defined by the Society of Automotive Engineers (SAE) specification J1113/41. A2-121 regulator 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.

C712C712

C712 alterna-

C712C712

C. E. Niehoff & Co.

BRUSHLESS ALTERNATORS

F+ Terminal

R Terminal

E Terminal

B+ Terminal

B Terminal

Figure 1  C711/C712 Alternator with A2-121 Regulator

Page 2

Figure 2  C711/C712 Alternator Wiring Diagram

TG0009A

C. E. Niehoff & Co.

BRUSHLESS ALTERNATORS

Section 2: Basic Troubleshooting

A. Tools and Equipment for Job

• Digital Multimeter (DMM)

• Ammeter (digital, inductive)

• CEN Regulator Bypass Adapter A10-129

• Jumper wire

• 12 V test light

B. Identification Record

Complete the following for proper troubleshooting:

Alternator model number ______________________

Regulator model number _______________________

Setpoints listed on regulator ___________________

C. Preliminary Check-out

Check condition of items in Table 1 and correct if necessary.

TABLE 1  System Conditions

SYMPTOM

Low Voltage Output

High Voltage Output

No Voltage Output

Check: loose drive belt; low

battery state of charge.

Check: current load on

system is greater than alternator can produce.

Check: defective wiring or

poor ground path; low regulator setpoint.

Check: defective alternator

and/or regulator. Check: wrong regulator. Check: high regulator set-

point. Check: defective regulator. Check: alternator. Check: broken drive belt. Check: battery voltage at

alternator output terminal. Check: defective alternator

and/or regulator.

ACTION

D. Basic Troubleshooting

Inspect charging system componentsInspect charging system components

Inspect charging system components

Inspect charging system componentsInspect charging system components for damagefor damage

for damage

for damagefor damage

Check connections at B– cable, B+ cable, and regulator harness. Repair or replace any damaged component before troubleshooting.

Inspect vehicle battery connectionsInspect vehicle battery connections

Inspect vehicle battery connections

Inspect vehicle battery connectionsInspect vehicle battery connections

Connections must be clean and tight.

Determine battery voltage and state of chargeDetermine battery voltage and state of charge

Determine battery voltage and state of charge

Determine battery voltage and state of chargeDetermine battery voltage and state of charge

If batteries are discharged, recharge or replace batteries as necessary. Electrical system cannot be properly tested unless batteries are charged 95% or higher.

Determine if battery isolator is usedDetermine if battery isolator is used

Determine if battery isolator is used

Determine if battery isolator is usedDetermine if battery isolator is used charging circuitcharging circuit

charging circuit

charging circuitcharging circuit

Check vehicle wiring diagram. If so, you must jumper out isolator before troubleshooting. See Chart 1 on page 4 for details.

Connect meters to alternatorConnect meters to alternator

Connect meters to alternator

Connect meters to alternatorConnect meters to alternator

Connect red lead of DMM to alternator B+ terminal and black lead to alternator B– terminal. Clamp inductive ammeter on B+ cable.

Operate vehicleOperate vehicle

Operate vehicle

Operate vehicleOperate vehicle

Observe charge voltage.

CAUTION

shut down system. Electrical system damage may occur if charging system is allowed to operate at high voltage. Go to Table 1 at left.

If voltage is at or below regulator setpoint, let charging system operate for several minutes to normalize operating temperature.

Observe charge volts and ampsObserve charge volts and amps

Observe charge volts and amps

Observe charge volts and ampsObserve charge volts and amps

Charge voltage should increase and charge amps should decrease. If charge voltage does not increase within ten minutes, continue to next step.

BatteryBattery

Battery is considered fully charged if charge

BatteryBattery

voltage is at regulator setpoint and charge amps remain at lowest value for 10 minutes.

If charging systemIf charging system

If charging system is not performing properly,

If charging systemIf charging system

go to Chart 1, page 4.

If charge voltage is above

16.5 volts, immediately

inin

TG0009A

Page 3

+ 5 hidden pages