Use Of The 5P300 Electrical Tester{0651} Caterpillar


Use Of The 5P300 Electrical Tester{0651}

Usage:

The 5P300 Electrical Tester can be used for test of 6, 8 and 12 volt batteries and 12 or 24 volt vehicle electrical systems. Instructions for the four most common tests are inside the lid of the electrical tester. If a starter current draw test is to be made, see Special Instruction Form SEHS7494 for the current draw of a specific machine. To do a complete battery test, see Special Instruction Form SMHS7633 "BATTERY TEST PROCEDURE".


1. AMMETER ZERO SET

2. AMMETER RANGE SELECTOR

3. VOLTMETER RANGE SELECTOR

4. FIELD CONTROL

5. CARBON PILE CONTROL

6. CLAMP-ON AMMETER PICKUP

7. AMMETER POWER LEADS

8. EXTERNAL VOLTMETER LEADS (EXT VOLTS)

9. FIELD LEADS

10. LOAD LEADS (9S3155 POS., 9S3156 NEG.)

battery cell:
The part of a battery that changes chemical energy into electrical energy.
biasing circuitry:
A circuit which keeps the correct amount of voltage for the operation of a transistor.
calibration:
The act of calibrating - to make an adjustment to an instrument to a standard position.
circuit breaker:
An automatic switch used to open a circuit.
cranking voltage:
The voltage needed by a starter to turn the crankshaft of an engine.
current draw:
The amount of current needed for the operation of a component.
directly proportional:
A value that increases or decreases at the same ratio as another value increases or decreases.
dropping and calibrating resistors:
Resistors used to keep an accurate reading on an instrument.
electrical potential:
The electrical energy available at some point in a circuit.
field:
A space around a conductor filled with magnetic lines of force when there is current flow.
field collapse:
The sudden removal of voltage from the field windings of a generator.
flux density:
A measurement of the strength of a magnetic field.
gain:
An increase of a value due to a circuit or part of a circuit.
gain compensating resistor:
Resistors which are used to keep a specific gain in a circuit.
Hall Effect Transducer:
A specific type of transducer.
leads:
Wires which connect an instrument to the point to be measured.
linearity:
An output directly proportional to an input.
magnetic field:
The area around a current carrying conductor having the characteristics of a magnet.
offset voltage:
A voltage which is used to keep a reference voltage of a component at a value other than zero.
offset voltage expanded accuracy scale:
A meter whose scale has a small range not starting at zero but one that can be read very accurately.
short circuit:
A circuit that has a connection between two or more components that is not desired.
simulate:
To give the effect of a specified condition.
switching:
Turning the knob of a switch from one position to another.
voltage drop:
A decrease in voltage between two points in a circuit.
windings:
Layers of wire around a core.

Specifications

AMMETER Range: 0 to 100 Amps DC and 0 to 1000 Amps DC full scale.

Accuracy: ± 5% of full scale at 70°F (21°C).

± 12% of full scale over 0°F to 150°F (-17°C to 66°C) range.

VOLTMETER Range: Internal - 9 to 18 VDC and 18 to 36 VDC.

External - 0 to 3 VDC and 0 to 12 VDC.

Accuracy: ± 3% of full scale at 70°F (21°C).

± 4% of full scale over 0°F to 150°F (-17°C to 66°C) range.

LOAD UNIT Load Test: 6VDC, 8VDC and 12VDC batteries.

Minimum Load: 10 Amps at 14.5 Volts.

Maximum Load: 800 Amps at 10.6 Volts (12 Volt batteries).

450 Amps at 5.8 Volts (6 Volt batteries).

Duty Cycle: At 600 Amps 12 Volt input:

(A) 15 seconds on and 6 minutes off.

(B) Test four 12 Volt batteries, one per minute and 30 minutes off.

(6 and 8 Volt batteries follow same duty cycle)

FIELD CIRCUIT Switch - spring loaded - off, 8 Amps maximum.

Circuit breaker protection.

Leads to fit all standard alternators.

LEAD LENGTH All leads 8 ft. (2.4 meters) except load leads which are 5 ft. (1.5 meters).

POWER INPUT 9 to 36 Volts DC.

WEIGHT 36 lb. (16.3 kg).

SIZE 14" x 18" x 7" (356mm x 457mm x 178mm).

Operation

General Information

(A) Ammeter Circuit

Mechanical zero adjust: Before any tests are made, the pointer of the AMPERES D.C. meter (1) must be on zero "0". If adjustment of the pointer is necessary, use a small screwdriver to turn adjustment screw (2) clockwise or counterclockwise to put the pointer exactly over the "0" on the left side of the scale.

Ammeter Operation: To operate the ammeter, connect POWER leads (3) to a 12 or 24 volt battery. The ammeter must have a minimum supply voltage of 10 volts. Read this voltage on the tester voltmeter (INT 18 or INT 36 scale).

Ammeter range; To make a test from "0" to "100" amperes, turn the AMP selector (4) to the "100" position. Put the AMP selector in the "1000" position when a test is made from "100" to "1000" amperes. If the amperage is not known, use the "1000" position. If the ammeter reading is then less than "100" amperes, turn the AMP selector to the "100" position.

Zero set: The ZERO SET knob (5) is used to electrically "zero" the ammeter after the power has been connected but before application of the test load.

Clamp-on ammeter pickup: To measure the amperage through a cable, put pickup (6) around the cable with arrow (7) on the clamp in the same direction as the flow of current. Example: When the starter is engaged, the flow of current is from the battery to the starter; the arrow must be toward the starter. During check of a charging system, the flow of current is from the generator or alternator to the battery and the arrow must then be toward the battery.

IMPORTANT: Make sure mating surfaces (A) of the pickup are clean or an incorrect reading will be the result.

NOTE: "Flow of current" is from battery positive to battery negative.

(B) Voltmeter Circuits

Mechanical zero adjust: Before any tests are made, the pointer of the VOLTS D.C. meter (8) must be on zero "0". If adjustment of the pointer is necessary, use a small screwdriver to turn adjustment screw (9) clockwise or counterclockwise to put the pointer exactly over the "0" on the left side of the scale.

Voltmeter scales: The voltmeter has four scales as shown below.

The voltmeter can be used for tests up to 36 volts. When VOLT SELECTOR knob (10) is turned to EXT 3 or EXT 12, the voltmeter is connected to EXT VOLTS leads (11). When the VOLT SELECTOR knob is turned to INT 18 or INT 36, the voltmeter is connected to POWER leads (3). Therefore, use the EXT VOLTS leads with the correct scale to measure 0 to 12 volts and the POWER leads and correct scale to measure 12 to 36 volts.

Voltage drop test: To make a voltage drop test, turn VOLT SELECTOR (10) to EXT 3 for a 12 volt system or EXT 12 for a 24 volt system and then connect EXT VOLTS leads (11).

(C) Field Circuit

When the field circuit is connected, the voltage regulator must be disconnected from the circuit. Control switch (12) must be held in the ON position. When the switch is released, a spring moves the switch to the OFF position. The field circuit has a circuit breaker for protection and leads (13) that will connect to all standard generators and alternators.

(D) Load Circuit (Carbon Pile)

The load circuit has positive (+) and negative (-) cables (14) and a load control knob (15). The clamp-on ammeter pickup must be on either load cable to measure amperage. The POWER leads must be connected to a good 12 or 24 volt power source to operate the ammeter.

Battery Leakage Test

(1) Turn the VOLT SELECTOR switch to the EXT 3 position.

(2) Connect the black negative (-) EXT VOLTS lead (A) to the negative (-) terminal of the battery.

(3) Look at the voltmeter while the red positive (+) EXT VOLTS lead (B) is moved around on the surface of the battery. Do not put the (+) EXT VOLTS lead on the straps that connect the battery cells or on the positive (+) terminal of the battery.

(4) If there is a voltage indication on the voltmeter, the battery is being discharged because the surface of the battery is wet or dirty. The battery must be thoroughly clean and dry.

Battery Capacity Test

NOTE: This test can be done on only one battery at a time.

(1) Turn the VOLT SELECTOR switch to the INT 18 position. Turn LOAD CONTROL (1) to the OFF position.

(2) Connect LOAD cables (2) and POWER leads (3) to the battery (red to positive and black to negative).

NOTE: During the capacity test on a 6 or 8 volt battery, the EXT VOLTS leads must be connected to the same 6 or 8 volt battery and the POWER leads must be connected to a good 12 volt or 24 volt power source.

(3) Adjust ZERO SET (4) until the ammeter pointer is on "0".

(4) Put the clamp-on ammeter pickup (5) around the positive (+) cable with arrow (6) in the direction shown. Make sure the mating surfaces of the pickup are clean.

(5) Turn AMP SELECTOR (7) to the "1000" position.

(6) Turn LOAD CONTROL (1) until the ammeter reads the test load value shown below. Look at the volt-meter reading.

(7) If the battery voltage is less than 9.0 volts for a 12 volt battery, 6.0 volts for an 8 volt battery or 4.5 volts for a 6 volt battery, do a complete battery test. See Special Instruction Form SMHS7633, "BATTERY TEST PROCEDURE".

Cranking Voltage And Current Draw Test

NOTE: Before this test is made, check all cables, connections, switches, wires and mechanical linkage. The bolts that hold the starter to the flywheel housing must also be tight.

(1) Turn VOLT SELECTOR (1) to the INT 18 position for 12 volt systems or to the INT 36 position for 24 volt systems.

(2) Connect POWER leads (2) to the battery; red to positive (+) and black to negative (-).

(3) Turn AMP SELECTOR (3) to the "1000" position.

(4) Adjust ZERO SET (4) until the ammeter pointer is on "0".

(5) Put clamp-on ammeter pickup (5) around the positive (+) battery cable with arrow (6) in the direction shown. Make sure the mating surfaces of the pickup are clean.

(6) For Gas Engines, disconnect the coil cable from the distributor cap and connect the coil cable to ground or connect the magneto ground terminal to ground.

(7) For Diesel Engines, put the governor control lever in the OFF position or disconnect the battery wire from the fuel solenoid.

(8) Use the electric starting motor to turn the engine crankshaft for 15 seconds. Make a note of the voltage and amperage. With the engine rotating at normal starting RPM, the voltage and amperage should be the same as the manufacturer's specifications.

A. If the engine is cranking at normal RPM and the amperage and voltage are the same as the specifications, the starting system is in good operating condition.
B. If the voltage is high with normal amperage and low cranking RPM, do a starting system voltage drop test.
C. High amperage can be caused by a hot or tight engine (mechanical resistance), a short circuit or mechanical resistance in the starting motor.
D. Low amperage, low cranking RPM, low voltage, failure to crank the engine, or any combination of the four can be caused by a weak battery or high resistance in the starting circuit. Do a battery capacity test and a starting system voltage drop test.

Starting System Voltage Drop Tests

(A) Positive Circuit (Battery Positive To Starter)

(1) Turn VOLT SELECTOR (1) to the EXT 3 position (if the voltage goes off the scale during the test, use the EXT 12 position).

(2) Connect EXT VOLTS leads (2) as shown.

NOTE: The voltmeter reading will be off the scale until the starter is engaged.

(3) For Gas Engines, disconnect the coil cable from the distributor cap and connect the coil cable to ground or connect the magneto ground terminal to ground.

(4) For Diesel Engines, move the governor control lever to the OFF position or disconnect the battery wire from the fuel solenoid.

(5) While the starter is used to turn the engine crankshaft, look at the voltmeter. If the voltmeter reading is more than shown in the table below, do the test again with the voltmeter connected across each switch, connection and length of cable between the starter and positive battery post, to find the point of high resistance. Points of high resistance cause a voltage drop as shown in the table below. This voltage subtracts from that of the battery and the result is less voltage at the starter.

(B) Ground Circuit (Battery Negative To Starter)

(1) Turn VOLT SELECTOR (1) to the EXT 3 position (if the voltage goes off the scale during the test, use the EXT 12 position).

(2) Connect EXT VOLTS leads (2) as shown for a 12 volt or 24 volt machine.

NOTE: The voltmeter reading will be off the scale until the starter is engaged.

(3) For Gas Engines, disconnect the coil cable from the distributor cap and connect the coil cable to ground or connect the magneto ground terminal to ground.

(4) For Diesel Engines, move the governor control lever to the OFF position or disconnect the battery wire from the fuel solenoid.

(5) While the starter is used to turn the engine crankshaft, look at the voltmeter. If the voltmeter reading is more than shown in the table below, do the test again with the voltmeter connected across each switch, connection and length of cable between the starter and negative battery post, to find the point of high resistance. Points of high resistance cause a voltage drop as shown in the table below. This voltage subtracts from that of the battery and the result is less voltage at the starter.

(C) Start Switch Circuit

NOTE: A high resistance in the circuit that engages the starter solenoid will cause a reduction of the current flow through the solenoid windings. The solenoid will not operate correctly, or will not operate at all, if this circuit resistance is too high. Often the result of this high resistance will be burnt main switch contacts in the solenoid that engages the starter.

(1) Turn VOLT SELECTOR (1) to the EXT 3 position (if the voltage goes off the scale during the test, use the EXT 12 position).

(2) Connect EXT VOLTS leads (2) as shown.

NOTE: The voltmeter reading will be off the scale until the starter is engaged.

(3) For Gas Engines, disconnect the coil cable from the distributor cap and connect the coil cable to ground or connect the magneto ground terminal to ground.

(4) For Diesel Engines, move the governor control lever to the OFF position or disconnect the battery wire from the fuel solenoid.

(5) While the starter is used to turn the engine crankshaft, look at the voltmeter. If the voltmeter reading is more than shown in the table below, do the test again with the voltmeter connected across each switch, connection and length of cable in the solenoid winding circuit, to find the point of high resistance. Points of high resistance cause a voltage drop as shown below. This voltage subtracts from that of the battery and the result is less voltage at the starter solenoid windings.

Alternator And Generator Output Test

(1) Turn VOLT SELECTOR (1) to the INT 18 position for 12 volt systems or to the INT 36 position for 24 volt systems.

(2) Connect the red POWER lead to the positive (+) terminal of the battery and the black POWER lead to the negative (-) terminal of the battery.

(3) Turn AMP SELECTOR (2) to the "100" position (or the "1000" position if the charging system is rated more than 100 amperes).

(4) Adjust ZERO SET (3) until the ammeter pointer is on "0".

(5) Put clamp-on ammeter pickup (4) around the positive (+) battery cable with arrow (5) in the direction shown. Make sure the mating surfaces of the pickup are clean.

(6) Start and run the engine at the manufacturer's test RPM. Good generator and alternator performance is shown when the voltage and amperage are the same as the manufacturer's specifications.

NOTE: If the battery or batteries are completely charged, put a load on the system by turning on as many accessories as possible in order to get maximum voltage and amperage.

(7) If the generator or alternator output is not the same as the manufacturer's specifications, operation of the generator, alternator or regulator is not correct. Do operation A or B below.

A. If the voltage regulator is inside the alternator, remove the alternator and test it on an electrical test bench.

B. If the generator or alternator and the regulator are separate parts, do an ALTERNATOR AND GENERATOR OUTPUT TEST WITH THE FIELD CONTROL.

Alternator And Generator Output Test With Field Control

(1) Turn VOLT SELECTOR (1) to the INT 18 position for 12 volt systems or to the INT 36 position for 24 volt systems.

(2) Connect the red POWER lead to the positive (+) terminal of the battery and the black POWER lead to the negative (-) terminal of the battery.

(3) Turn AMP SELECTOR (2) to the "100" position (or the "1000" position if the charging system is rated more than 100 amperes).

(4) Adjust ZERO SET (3) until the ammeter pointer is on "0".

(5) Put clamp-on ammeter pickup (4) around the positive (+) battery cable with arrow (5) in the direction shown. Make sure the mating surfaces of the pickup are clean.

(6) Disconnect field wire (C) from the alternator or generator.

(7) Connect blue FIELD lead (D) to the field terminal of the alternator or generator.

(8) For "A" circuits: Connect yellow FIELD lead (E) to ground.

For "B" circuits: Connect yellow FIELD lead (E) to the battery terminal of the alternator or generator.

NOTE: An "A" circuit is one where the field resistance and contact points of the regulator are connected between the FIELD terminals of the generator and ground so the generator field is grounded through the regulator. A "B" circuit is one where the field resistance and contact points of the regulator are connected between the FIELD terminals and the BATTERY terminal of the generator; the field is permanently connected to ground inside the generator. If the type of circuit is not known, connect the FIELD leads as an "A" circuit and do steps 9 through 11. If the output is zero, connect the FIELD leads as a "B" circuit and do steps 9 through 11.

(9) Start the engine.

(10) Hold the FIELD CONTROL switch in the ON position and operate the engine at the manufacturer's test speed. Make a record of the amperage and voltage.


NOTICE

Decrease the engine speed to low idle before the FIELD CONTROL switch is permitted to go back to the OFF position.


(11) If the alternator or generator output is the same as the specifications, the voltage regulator has a defect. If the alternator or generator output is not the same as the specifications, the alternator or generator has a defect.

(12) Disconnect FIELD leads (D) and (E). Connect field lead (C) to the alternator or generator.

Electrical Accessory Current Draw Test

NOTE: The current draw can be checked on any vehicle electrical circuit.

(1) Turn VOLT SELECTOR (1) to the INT 18 position for 12 volt systems or to the INT 36 position for 24 volt systems.

(2) Connect POWER leads (2) to the battery (red to positive and black to negative).

(3) Turn AMP SELECTOR (3) to the "100" position.

(4) Adjust ZERO SET (4) until the ammeter pointer is on "0".

(5) Put clamp-on ammeter pickup (5) around the positive (+) battery cable with arrow (6) in the direction shown. Make sure the mating surfaces of the pickup are clean.

(6) Turn on the accessory to be tested. The current draw should be the same as the manufacturer's specifications.

A. High current draw can be caused by a short circuit in the system. If an electric motor is in the circuit, the high current draw can be caused by friction inside the electric motor or friction inside the accessory being driven.
B. Low current draw is caused by too much resistance in the circuit being tested, such as from a loose connection, or corrosion. Do an electrical accessory circuit voltage drop test.

Electrical Accessory Circuit Voltage Drop Tests

(A) Positive Circuit Test (Battery Positive To Accessory)

(1) Turn the accessory on.

(2) Turn VOLT SELECTOR (1) to the EXT 3 position (if the voltage goes off the scale during the test, use the EXT 12 position).

(3) Connect EXT VOLTS leads (2) as shown.

(4) Look at the reading on the voltmeter.

(5) If the voltmeter reading is more than that shown in the table below, do the test again with the voltmeter connected across each connection in the circuit to find the point of high resistance.

(B) Ground Circuit Test (Battery Negative To Accessory)

(1) Turn the accessory on.

(2) Turn VOLT SELECTOR (1) to the EXT 3 position (if the voltage goes off the scale during the test, use the EXT 12 position).

(3) Connect EXT VOLTS leads (2) as shown.

(4) Look at the reading on the voltmeter.

(5) If the voltmeter reading is more than that shown in the table below, do the test again with the voltmeter connected across each connection in the circuit to find the point of high resistance.

Troubleshooting And Calibration

General Information

The 5P300 Electrical Tester is used for testing 12 or 24 volt vehicle electrical systems. The tester contents are: A clamp-on ammeter, a voltmeter and a carbon pile. The tester can be used to check the starting and charging circuits, battery condition and the vehicle accessories.

The ammeter uses a Hall Effect Transducer in the clamp-on ammeter pickup to measure (find) the magnetic field strength (flux density) around the conductor that is carrying (has) current. The Hall Effect Transducer changes the magnetic field into an electrical potential. The magnetic field is directly proportional to the current that flows through the conductor, and the transducer output voltage is directly proportional to the magnetic field. Some internal components of the ammeter are: Q1 - the main component in the current source, Q2 - the main component in the oscillator, and IC1 - operational amplifier. The IC1 amplifies (changes) the signal from the Hall Effect Transducer in order to drive the output meter M103.

The voltmeter uses the expanded scale principle on the internal position to increase accuracy. The voltmeter circuit has potentiometers for calibration at each voltmeter range. The field circuit has a voltage sensitive resistor which prevents field collapse during the alternator or generator test.

The load circuit is a carbon pile which is a variable low resistance load. The result of this load is a high current draw to the component being tested.

Equipment Needed


1) 5P8608 Ammeter Calibrator Group

2) Volt-Ohm Meter (VOM) or a Digital Voltmeter

3) 12 or 24 Volt Battery (fully charged) or a Variable Voltage Supply

4) Oscilloscope (not shown)

General Checks

Inspect the electrical tester for defects such as loose solder connections, burnt components, broken wires, and terminals with a short circuit. Visually inspect the carbon pile in the load circuit for damaged or burnt carbon plates.

Turn the mechanical zero adjust of the meters through their range. The meter pointer should move to each side of zero a minimum of two divisions (marks). If not, remove the meter from the tester and see if the zero adjust screw correctly engages the meter movement. If zero adjustment is not possible, purchase (get) a new meter from Sun Electric Corp. (address on page 23).

The field circuit switch permits application of maximum voltage to the field of the alternator or generator. Use a continuity check to learn the condition of the switch and the circuit breaker.

Check the voltage sensitive resistor with an ohmeter. The correct resistance is approximately 10,000 ohms.

Ammeter Troubleshooting

(1) Connect the POWER leads to a 12.6 volt power supply (12 volt automotive storage battery); red to positive (+) and black to negative (-).

(2) Turn the AMP SELECTOR to the "100" position.

(3) Turn the ZERO SET throughout its range of rotation. If there is no indication of the ammeter, the probable causes are:

a) The POWER leads are not correctly connected. NOTE: For protection, the unit will not operate if the POWER leads are connected in reverse polarity.
b) A defect in a component or connection. Check for correct voltage at the following test points as shown on the wiring diagram and photograph on page 21 or page 22.

Oscilloscope trace of test point F to E. Vertical deflection is 10 volts/division. Sweep speed is 10 microseconds/division.

(4) If all the test point values are correct and there is still no meter indication, check for voltage across meter M103. With the AMP SELECTOR in the "100" position, turn the ZERO SET from one end of its range to the other; there should be less than .25 VDC present.

(5) If there is no voltage at meter M103, check the resistance of the pickup as shown below.

a) Disconnect the 12 volt power supply.

b) Measure the resistance J30 (Red) to J31 (Black). A resistance of 30 to 70 ohms is normal.

c) Measure the resistance J28 (White) to J29 (Green). This resistance should be two to three times the resistance in the above step.

NOTE: For calibration of the ammeter, use the same clamp-on ammeter pickup assembly sent with the unit. If a pickup assembly is changed, calibration of the unit is again necessary before use.

(6) If there is no output and the pickup assembly checks out correctly, the probable defect is in the operational amplifier circuit (IC1). Install a new IC1 component if all previous checks fail to correct the problem or if the zero adjust cannot be centered (put in the center position) using the internal zero adjust.

(7) If the ammeter indication is above or below zero but cannot be adjusted to zero, R14 probably needs adjustment. See the section AMMETER CALIBRATION.

(8) To check the ammeter calibration, connect the 5P8608 Calibrator and the VOM as indicated in the AMMETER CALIBRATION section. The ammeter indication should be the same as the conditions given in step 18 of the AMMETER CALIBRATION section. If the ammeter indication is to the left of zero, the pickup assembly is in the reverse position. If there is no indication, troubleshoot as necessary. If the ammeter indication is up on the scale but not within tolerance, calibration of the unit is necessary.

Ammeter Calibration

(1) Put the 5P300 Electrical Tester in a horizontal position as shown and disconnect the power.

(2) Before the start of calibration, the pointer of the AMPERES D.C. panel meter must be on the zero "0". If pointer adjustment is necessary, use a small screwdriver to turn adjustment screw (1), either clockwise or counterclockwise, to put the pointer exactly over the zero "0" on the left side of the scale.

(3) Connect the 5P300 Electrical Tester POWER leads (2) to a 12 or 24 volt D.C. power supply, red to positive (+) and black to negative (-).

(4) Turn AMP SELECTOR (3) to the "100" position.

(5) Turn ZERO SET (4) to the center of its rotation.

(6) Adjust R14 (zero adjust 100, see page 21) to get an ammeter reading of zero "0".

(7) Connect a 12 volt power supply (battery or 3 amp power supply) to the 5P8608 Calibrator 12 VDC terminals (5).

(8) Connect an external voltmeter (VOM) with at least 2% full scale accuracy to the VOLTMETER terminals (6) of the calibrator. Connect the coil leads to the calibrator COIL terminals (7).

(9) Fasten the clamp-on ammeter pickup (8) over the calibrator coil. The arrow on the pickup must always be in the direction of current flow. Reverse the pickup position if the indication on the ammeter is not up scale.

(10) Adjust CURRENT SELECTOR (9) so the ammeter will read approximately 1/3 of full scale. Press PUSH TO CALIBRATE button (10) only long enough to get an accurate reading, since heat will increase in the coil.

(11) Compare ammeter reading with the voltage shown on the VOM (1 volt = 100 amps).

(12) Adjust R6 (Cal. 100A) to get an ammeter reading that is 100 times the VOM reading in volts.

(13) Do steps 10, 11 and 12 again at approximately 2/3 of full scale.

(14) Turn AMP SELECTOR (3) to the "1000" position.

(15) Adjust R15 (zero adjust 1000) to get an ammeter reading of zero "0".

(16) Turn AMP SELECTOR (3) from 1000 to 100. The meter indication should be within one (1) division of zero "0".

(17) Do steps 10, 11, 12 and 13 again for the "1000" position. Adjust R26 (Cal. 1000) to get an ammeter reading that is 100 times the VOM reading in volts.

(18) If the ammeter is correctly adjusted, the following conditions are necessary:

a) The ability to put the ammeter in the zero "0" position with ZERO SET (4) near the center of its rotation.
b) The ammeter reading should always be within one (1) division of the zero "0" when the AMP SELECTOR (3) is moved between the 100 and the 1000 amp scales.
c) The ammeter indication is ± 1 amp of the amperage reading on the calibrator voltmeter with AMP SELECTOR (3) in the "100" position and the 5P8608 Calibrator CURRENT SELECTOR (9) in the "2" position.
d) The ammeter indication is ± 10 amps of the amperage reading on the voltmeter with AMP SELECTOR (3) in the "1000" position and the calibrator CURRENT SELECTOR (9) in the "6" position.

NOTE: Resistors R24 and R25 are gain compensating resistors for the 100 and 1000 amp ranges, respectively. Selection of their values are made so the calibrating resistors R6 and R26 are in their center area of adjustment when the unit is in correct calibration. Use the table below to find the specific pickup assembly for certain values of resistors R24 and R25.

The ratio of the output voltage (in microvolts) of the Hall Effect Transducer to the applied magnetic field can be considered as the gain of the transducer. Since the gain of each transducer is not exactly the same, identification of the range of the transducers used in each clamp-on pickup assembly is by a letter value A, B, C or D. Transducers with letter A have less gain while transducers with the letter D have more gain. These letter values are given on the inside surface of the clamp handle.

Table for 5P300

If identification of the pickup assembly is not known, current flow can be used to check R24. If the current is too low, the value of R24 is too high. If the current is too high, the value of R24 is too low.

NOTE: There is a difference between the 2P5540 Clamp-on Pickup Assembly and the 5P300 (5P969) Clamp-on Pickup Assembly. The pickup assemblies can not be used as replacements for each other. There is little visual difference between the two pickup assemblies, and they have no part number mark on them. The 5P300 Pickup Assembly has larger magnetic pole shoes than the 2P5540.

Voltmeter Troubleshooting

(1) If the voltmeter gives no indication, check for potential at the meter M104.
(2) A potential at the voltmeter is an indication of a meter failure.
(3) No potential at the meter is an indication of a failure in the leads, switch, or component connections.

Voltmeter Calibration

(1) Check the external voltmeter positions for accuracy by application of a known voltage. To do this, make the mechanical zero adjustment and then measure a voltage source known to be 10 volts. Remove the voltage. Again measure the 10 volt source, then decrease the voltage in steps of 1 volt to check linearity.

(2) If the voltmeter reading is not correct, check the resistance of R109 and R110.

(3) For calibration of the internal 18 volt scale, first measure a voltage source known to be 9 volts, then adjust calibration resistor R55 for a 9 ± 0.5 volt reading on the meter. Similarly, use a known 18 volt source, and adjust the resistor R53 for an 18 ± 0 volt reading on the meter.

(4) Do step 3 again until both ends of the scale are on calibration.

(5) For calibration of the internal 36 scale, use the same method, and adjust R57 at 18 volts and R59 at 36 volts.

Wiring Diagram And Test Points

(A) Earlier Models

(B) Later Models

NOTE: Some models may only have part of the revisions found between "earlier" and "later" model schematics.

Parts List

(A) Earlier Models

(B) Later Models

Caterpillar Information System:

Using 8S2305, 9S228 And 9S240 Rack Position Tool Groups{650, 1250} Using 8S2305, 9S228 And 9S240 Rack Position Tool Groups{650, 1250}
Reconditioning Dimensions for Track Links, Idlers, Rollers and Scraper Elevator Rollers{4154, 4159, 4171, 4180, 6248, 6260} Reconditioning Dimensions for Track Links, Idlers, Rollers and Scraper Elevator Rollers{4154, 4159, 4171, 4180, 6248, 6260}
Troubleshooting And Repair Of The 5P2160 Engine Horsepower Meter Arrangement<FONT SIZE=-1>*</FONT>{0781, 0782} Troubleshooting And Repair Of The 5P2160 Engine Horsepower Meter Arrangement<FONT SIZE=-1>*</FONT>{0781, 0782}
Installation Of Flywheel Adapter Groups(Allison Transmissions){1157} Installation Of Flywheel Adapter Groups(Allison Transmissions){1157}
Use Of The 9S1990 And 1P7400 Battery Charger Testers{0785} Use Of The 9S1990 And 1P7400 Battery Charger Testers{0785}
Use of 7S1100 Hydraulic Press Arrangement{0738} Use of 7S1100 Hydraulic Press Arrangement{0738}
Using 5P170 Or 5P4180 Hydraulic Hose Press Arrangement{0624} Using 5P170 Or 5P4180 Hydraulic Hose Press Arrangement{0624}
Parts Cleanliness Testing for Caterpillar Dealers - Visually Identifying Particulate Parts Cleanliness Testing for Caterpillar Dealers - Visually Identifying Particulate
Parts Cleanliness Testing for Caterpillar Dealers - Cleanliness Testing Process Parts Cleanliness Testing for Caterpillar Dealers - Cleanliness Testing Process
Parts and Components Cleaning Guide Parts and Components Cleaning Guide
Alignment of Two-Bearing Generators Alignment of Two-Bearing Generators
MTA Assembly and Service Manual MTA Assembly and Service Manual
Using The 5P2160 Engine Horsepower Meter Arrangement<FONT SIZE=-1>*</FONT>{0781, 0782} Using The 5P2160 Engine Horsepower Meter Arrangement<FONT SIZE=-1>*</FONT>{0781, 0782}
Alignment of Two Bearing Generators{4450} Alignment of Two Bearing Generators{4450}
Troubleshooting And Repair Of The 1P3500 And 2P8280 Injection Timing Groups{0782} Troubleshooting And Repair Of The 1P3500 And 2P8280 Injection Timing Groups{0782}
Service Information And Instructions For Use Of 5P3600 Hydraulic Flow Meter{0650, 5050} Service Information And Instructions For Use Of 5P3600 Hydraulic Flow Meter{0650, 5050}
Installation Of 7N4295 Rebuild Kit For Refrigerant Compressor - Clutch And Drive{1802} Installation Of 7N4295 Rebuild Kit For Refrigerant Compressor - Clutch And Drive{1802}
5P6590 Tester Schematic{0785, 0709, 1406, 1408} 5P6590 Tester Schematic{0785, 0709, 1406, 1408}
Installation Of Coolant Conditioner Group{1350} Installation Of Coolant Conditioner Group{1350}
INSTALLATION, OPERATION AND MAINTENANCE OF 9N3771 INJECTION GROUP (CETANE){1250} INSTALLATION, OPERATION AND MAINTENANCE OF 9N3771 INJECTION GROUP (CETANE){1250}
5P8579 Air Conditioning Charging And Testing Tool Group{1802, 0768, 0774} 5P8579 Air Conditioning Charging And Testing Tool Group{1802, 0768, 0774}
Welding Procedure For Sprocket Rim Replacement{4156} Welding Procedure For Sprocket Rim Replacement{4156}
Using The 5P-4150 Nozzle Testing Group{0782} Using The 5P-4150 Nozzle Testing Group{0782}
Use of Piston Pin Bearing Removal and Installation Tools{1218} Use of Piston Pin Bearing Removal and Installation Tools{1218}
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