Keithley 2100 User Manual page 27

Model 2100 6 1/2-Digit Resolution Digital Multimeter User's Manual
Current input fuses
The Model 2100 has two 3A fuses in the front and rear current input terminals, and an additional
7A fuse in series with either the front or rear current input fuse (depending on the front or rear
panel switch position) for added protection against a strong current pulse. If a strong current pulse
overloads the 7A fuse, it will blow quickly, thus saving the 3A fuse and the instrument's internal
circuitry (see
Figure 2-19
Current protection using 3A and 7A current input fuses in series
The two main fuses located in the front and rear current input terminals of your Model 2100 are 3A,
250V, 5x20mm fast-acting glass fuses (Keithley Instruments part number FU-99-1). The additional
current input fuse is a 7A, 250V, 5x20mm fast-acting ceramic tube fuse. See the following text for
instructions on how to replace these fuses if they become damaged.
To change the 3A front or rear panel current input terminal fuses:
WARNING
CAUTION
NOTE
2100-900-01 Rev. D / September 2011
Figure 2-19).
Before replacing the power line fuse or current input fuses, verify that the
multimeter is disconnected from AC power. You must be qualified personnel
to perform this procedure.
For continued protection against fire or instrument damage, only replace the
fuses with the same type and rating. If the instrument repeatedly blows fuses,
have the unit serviced at an authorized repair facility.
Instructions for replacing the front panel current input terminal fuse are depicted here; the
rear panel current input terminal fuse can be changed using the same procedure.
Return to Section Topics
Section 2: Getting Started
2-13