C.E. Niehoff & Co. C622 Troubleshooting Guides

600 Series Troubleshooting Guide

for C622 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.

DANGER

death or substantial property damage if ignored.

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 cause severe personal inury,

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 – 7

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 charging 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 battery state 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 setpoint 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, system volts reading will increase up to regulator setpoint and the system amps will decrease to low level (depending on other loads) as the batteries recover and become fully charged.

• Low Amps: A 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: A system amps value which can 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 rates of charge amps.

• High Amps: A system amps value which can cause 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 rates of charge amps.

• Battery Voltage: Steady-state voltage value as measured with battery in open circuit with no battery load. This value relates to battery state of charge.

• Charge Voltage: A 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: A voltage value obtained when measuring voltage at battery positive terminal or alternator B+ terminal.

• Surface Charge: A higher than normal battery 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: A change in the strength 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: A normal condition which occurs when the load demand on the alternator is greater than rated alternator output at given rotor shaft RPM.

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Page 1

Section 1: Wiring Diagram

CEN C622 Alternator Description and Operation

C622 28 V 100 A/84 V 50 A alternator is internally rectified. 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 (commonly an oil pressure switch), which activates regulator. Field coil is then energized. 84 V system is not energized until 28 V system is energized. 84 V and 28 V circuit output currents are controlled by separate SCRs in the drive end housing. Alternator output current is self-limiting and will not exceed rated capacity of alternator.

A2-307 regulator used with these units:

• maintains alternator output voltage at regulated settings as vehicle electrical loads are switched on and off.

• monitors 28 V and 84 V systems separately.

A2-604 battery charge equalizer and A9-069 harness used with these units:

• equalizes six 12 V batteries connected in series.

• turns on when charge voltage is above 78 volts.

84 V LED Indicator

28 V B+ Terminal

Tricolor diagnostic LEDs (2 side-by-side)

84 V 28 V

A2-307 Regulator LEDs

NEG 84 V terminal

28 V E Terminal

POS 84 V terminal

28 V LED Indicator

28 V B– Terminal (either side)

DANGER

system. Severe personal injury or death will result from contact.

HIGH VOLTAGE. Use extreme caution when working around 84 V

Figure 1 — C622 Alternator Terminals

Page 2

Figure 2 — C622 Alternator with Regulator

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Section 2: Basic Troubleshooting

A. Tools and Equipment for Job

• Digital Multimeter (DMM)

• Ammeter (digital, inductive)

• Jumper wires

B. Identification Record

List the following for proper troubleshooting:

Alternator model number _____________________

❏ ❏

Regulator model number _____________________

❏

Setpoint listed on regulator ___________________

❏

Battery charge equalizer model number _______

❏

Harness model number ______________________

C. Preliminary Check-out

Check symptoms in Table 1 and correct if necessary.

TABLE 1 – System Conditions

SYMPTOM

Low Voltage Output

High Voltage Output

No Voltage Output

No 84 V 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 setpoint. Check: defective regulator. Check: alternator. Check: presence of energize

signal. Check: battery voltage at alter-

nator output terminal. Check: defective alternator

and/or regulator.

Go to “Steady Amber” in

Table 2, page 4.

ACTION

D. Basic Troubleshooting

DANGER

system. Severe personal injury or death will result from contact.

1. Inspect charging system components Check connections at ground cables, positive cables, and regulator harness. Repair or replace any damaged component before troubleshooting.

2. Inspect battery charge equalizer connections Connections must be in proper sequence and clean and tight. See Figure 4, page 6.

3. Inspect connections of vehicle batteries Connections must be clean and tight.

4. Determine battery type, voltage and state

of charge

Batteries must be all the same type for system operation. If batteries are discharged, recharge or replace batteries as necessary. Electrical system cannot be properly tested unless batteries are charged 95% or higher. See page 1 for details.

5. Connect meters to alternator Connect red lead of DMM to alternator 28 V B+ terminal and black lead to alternator 28 V B– terminal. Clamp inductive ammeter on 28 V B+ cable.

6. Operate vehicle Observe charge voltage.

CAUTION

or 85 V for 84 V system, immediately shut down system. Electrical system damage may occur if charging system is allowed to operate at excessive 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.

7. Observe charge volts and amps in each circuit Charge voltage should increase and charge amps should decrease. If charge voltage does not increase within ten minutes, continue to next step.

8. Batteries are considered fully charged if charge voltage is at regulator setpoint and charge amps remain at lowest value for 10 minutes.

9. If charging system is not performing properly, go to Chart 3, page 7.

HIGH VOLTAGE. Use extreme caution when working around 84 V

If charge voltage is above 33 volts for 28 V system

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