Fluke 787 user manual Replacing a Fuse

ProcessMeter

Maintenance

Replacing a Fuse

!Warning

To avoid personal injury or damage to the meter, use only the specified replacement fuse, 440 mA 1000V fast-blow, Fluke PN 943121.

Both current input jacks are fused with a separate 440 mA fuse. To determine if a fuse is blown:

1.Turn the rotary switch to mA A L.

2.Plug the black test lead into COM, and the red test lead into cA.

3.Using an ohmmeter, check the resistance between the meter test leads. If the resistance is about 1Ω, the fuse is good. An open means the fuse is blown.

4.Move red test lead to dmA.

5.Using an ohmmeter, check the resistance between the meter test leads. If the resistance is about 14Ω, the fuse is good. An open means the fuse is blown.

If a fuse is blown, replace it as follows. Refer to Figure 11 as necessary:

1.Remove the test leads from the meter and turn the rotary switch to OFF.

2.Remove the battery door.

3.Remove the three Phillips-head screws from the case bottom and turn the case over.

4.Gently lift the bottom of the front of the case (nearest the input/output jacks) until the top unsnaps from the rear half of the case.

5.Replace the blown fuse with the exact type specified: 440 mA 1000V fast-blow fuse, Fluke PN 943121. Both fuses are the same type.

6.Make sure the rotary switch is in the OFF position.

7.Fit the top of case together, engaging the two snaps (item A). Make sure that the gasket is properly seated.

8.Close the case and reinstall the three screws.

9.Replace the battery door.

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