Checking And Replacing Fuses - Fluke ProcessMeter 787 Calibration Manual

Model 787
Calibration Manual

Checking and Replacing Fuses

To avoid electric shock or personal injury, remove the test leads and
any input signals before replacing a fuse. Make sure that the battery
door and case are closed and secured before operating the
ProcessMeter.
To avoid injury or damage to the ProcessMeter, use ONLY specified
replacement fuses with the amperage, voltage, interrupt and speed
ratings shown in Table 13.
Both current input terminals are fused with a separate 440 mA fuse.
To determine if a fuse is blown:
1. Turn the rotary switch to
2. Plug the black test lead into
3. Using an ohmmeter, check the resistance between the ProcessMeter test leads.
If the resistance is about 1 , the fuse is good. An open means the fuse is blown.
4. Move red test lead to
5. Using an ohmmeter, check the resistance between the ProcessMeter test leads.
To replace a fuse, refer to Figure 2 and do the following:
1. Turn the rotary switch to
2. Remove the battery door by using a flat-blade screwdriver to turn the battery door
3. Remove the three Phillips-head screws from the case bottom and turn the case over.
4. Gently lift the input terminal-end of the case top to separate the two halves of the
5. Remove the fuse by gently prying one end loose, then sliding the fuse out of its
6. Replace the fuse only with a 440 mA 1000 V fast-blow fuse. (Fluke PN 943121.)
Both fuses are the same type.
7. Verify that the rotary switch and the circuit board switch are in the
8. Place the case top on the case bottom, ensuring that the gasket is properly seated and
9. Reinsert the three case bottom screws and the battery door.
10
If the resistance is about 14 , the fuse is good. An open means the fuse is blown.
ProcessMeter face down.
screws 1/4-turn counterclockwise.
case.
bracket.
the case halves snap together above the LCD end. (See Figure 2.)
Warning
mA A L.
COM , and the red test lead into
mA .
, remove the test leads from the terminals, and hold the
OFF
A .
position.
OFF