Book: 23227143 (8-24-2010) Rev CPage35
General Measuring Guidelines:
Since the electrical system uses sealed connectors and splices, access of test
points can be difficult. It is recommended that a test probe kit be used to access
the signals to prevent damage to WJDes and connectors. Back probing
connectors and insulation piercing test probes can cause damage that can cause
future failures.
Measuring Voltage:
A digital voltmeter is recommended to make measurements. Voltage
measurements are made by connecting the RED + lead to the desired signal and
the BLACK lead to the common. The test lead connections must be secure or
incorrect readings will result. Use circuit common for the Black lead, not chassis
ground or other metal connection. Circuit common will be any of the BROWN
WJDes or battery negative can be used.
IMPORTANT INFORMATION
DO NOT USE MACHINE FRAME, SHEET METAL, PIPING OR OTHER METAL
COMPONENTS AS COMMON OR GROUND WHEN MAKING VOLTAGE OR
FREQUENCY MEASUREMENTS.
Measuring Resistance:
Extra care must be taken when making resistance measurements. Test probe
connections are crucial to correct readings. Ensure the test probe makes a solid
connection with the WJDe(s) or connector pin(s) under test. the test probe kit
may help with these types of measurements. Make sure system power is turned
OFF while making resistance measurements.
Measuring Frequency:
Frequency is measured in the same manner as voltage, but the meter is set for
"HZ" or frequency. Good connections are important or false readings will occur.
Measuring Duty Cycle:
To measure duty cycle, setup the meter as if measuring frequency or voltage.
Select the "%" or duty cycle function and take the measurements. As of the date
of this writing, Fluke is the only known digital voltmeter that has the duty cycle
feature. The Fluke Model 87 Digital Meter has the duty cycle function.
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