Keithley 2500, Service Manual

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3-2 Routine Maintenance Model 2500 Service Manual
Introduction
The information in this section deals with routine type maintenance that can be performed
by the operator and includes information on line voltage selection and line fuse
replacement.
Line voltage selection
WARNING Disconnect the line cord at the rear panel and remove all test leads
connected to the instrument before changing the line voltage.
The Model 2500 operates from a line voltage in the range of 100V / 120V / 220V / 240V,
±10% at a frequency of 50 or 60Hz. Before plugging in the unit, make sure the line voltage
setting seen through the small window in the power module (
Figure 3-1 ) is correct for the
line voltage in your area.
WARNING Operating the instrument on an incorrect line voltage may cause dam-
age, possibly voiding the warranty.
If the voltage setting is not correct, change it as outlined below.
1. Pry the small tab that secures the fuse holder to the power module, then remove the
fuse holder.
2. Pull out and rotate the fuse carrier to the correct line voltage setting, then install it
in the fuse holder. Make sure the line voltage shown in the window is correct. Also
make sure the fuse rating for the expected line voltage is correct. (See “Line fuse
replacement.”)
3. Reinstall the fuse holder in the power module, making sure it is seated fully.
Line fuse replacement
WARNING Disconnect the line cord at the rear panel and remove all test leads
connected to the instrument before replacing the line fuse.
The power line fuse is accessible from the rear panel and is integral with the AC power
module (
Figure 3-1 ).