Fluke 43B
Users Manual
The terms ‘Isolated’ or ‘Electrically floating’ are used in this manual to indicate a measurement in which the Fluke 43B COM (common, also called ground) is connected to a voltage different from earth ground.
The term “Grounded” is used in this manual to indicate a measurement in which the Fluke 43B COM (common) is connected to an earth ground potential.
The Fluke 43B common inputs (red INPUT 1 shield, gray INPUT 2 shield, and black
fault protection. This is denoted by the 
symbol.
The input connectors have no exposed metal and are fully insulated to protect against electrical shock. The black 4 mm banana jack COM (common) can be connected to a voltage above earth ground for isolated (electrically floating) measurements and is rated up to 600V rms above earth ground.
If
Using the Fluke 43B in a manner not specified may impair the protection provided by the equipment. Before using, inspect the test leads for mechanical damage and replace damaged test leads!
If it is likely that safety has been impaired, turn the Fluke 43B off and disconnect it from the line power. The matter should then be referred to qualified personnel. Safety is likely to be impaired if, for example, the Fluke 43B fails to perform the intended measurements or shows visible damage.
Current Probe
Warning
•Use extreme caution when clamping the current probe around uninsulated conductors or bus bars.
•Never use the current probe on circuits rated higher than 600V in overvoltage category III (CAT III) of
•Keep your fingers behind the finger guard.
Do not use a probe that is cracked, damaged, or has a defective cable. Such probes should be made inoperative by taping the clamp shut to prevent operation.
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