Keithley 2000, User Manual, Page: 27 / 280

Setting line voltage and replacing fuse
A rear panel fuse located next to the AC receptacle protects the power line input of the instru-
ment. If the line voltage setting needs to be changed or the line fuse needs to be replaced, per-
form the following steps.
WARNING Make sure the instrument is disconnected from the AC line and other equip-
ment before changing the line voltage setting or replacing the line fuse.
1. Place the tip of a flat-blade screwdriver into the power module by the fuse holder assem-
bly (see Figure 2-3). Gently push in and to the left. Release pressure on the assembly and
its internal spring will push it out of the power module.
2. Remove the fuse and replace it with the type listed in Table 2-1.
CAUTION For continued protection against fire or instrument damage, only replace
fuse with the type and rating listed. If the instrument repeatedly blows fuses,
locate and correct the cause of the trouble before replacing the fuse. See the
optional Model 2000 Repair Manual for troubleshooting information.
3. If configuring the instrument for a different line voltage, remove the line voltage selector
from the assembly and rotate it to the proper position. When the selector is installed into
the fuse holder assembly, the correct line voltage appears inverted in the window.
4. Install the fuse holder assembly into the power module by pushing it in until it locks in
place.
Table 2-1
Fuse ratings
Line voltage Fuse rating Keithley P/N
100/120V
220/240V 0.25A slow-blow 5
×
20mm
0.125A slow-blow 5
×
20mm
FU-96-4
FU-91
Basic Measurements 2-9