Table of Contents
Advertisement
MAINTENANCE
Table
7-1. Line
Voltage
Selection
*Requires special power transformer.
7.3 FUSE REPLACEMENT
The paragraphs below give procedures for replacing the
line, and digital supply fuses. The line fuse is accessible
from the rear panel, but the top cover must be removed
in order to gain access to the digital supply fuse.
WARNING
Disconnect
the instrument
from the power
line
and all other
equipment
before
removing
the
top cover
or replacing
fuses.
7.3.1 Line Fuse Replacement
The rear panel line fuse protects the power line input of
the instrument.
This fuse can be replaced as follows:
1. With the power off, place the end of a flat-bladed
screwdriver
into the slot in the rear panel fuse holder.
Press in gently and rotate the fuse carrier approximately
one-quarter turn counterclockwise.
Release pressure on
the holder and allow the internal
spring to push the
carrier and fuse out of the holder.
2. Remove the fuse and replace it with the type recom-
mended in Table 7-Z.
CAUTION
Do not
use a fuse
with
a higher
rating
than
specified,
or instrument
damage
may occur.
If
the instrument
repeatedly
blows
fuses,
locate
and
correct
the
cause
of the
trouble
before
resuming
operation
of the unit.
3.
Install the new fuse and fuse carrier by reversing the
above procedure.
Table
7-2.
Line
Fuse
Selection
7.32 Digital Supply
Fuse Replacement
An internal fuse protects the +5V digital supply from over
current conditions.
Replace this fuse as follows:
1. Remove the top cover to gain access to the fuse.
2. Remove the digital supply fuse from the fuse clips with
a fuse puller
or similar
tool. Figure 7-l shows fuse
location.
3. Replace the fuse with the following type: 6A, I25V, Nor-
mal Blo, 8AG, Keithley
Part Number FU-73.
CAUTION
Do not
use a fuse
with
a higher
rating
than
specified
above,
or instrument
damage
may
occur.
4. After replacing
the fuse, replace the top cover and
secure it properly before resuming normal operation.
7.4 OPTION INSTALLATION
Installation
of the optional
Model
1944 A/D module is
detailed in the following
paragraphs.
7.4.1 Installation
Procedures
Refer to Figure 7-2 and install the Model 1944 as follows.
WARNING
Disconnect
the line cord and all other
equip-
ment from the Model
194 before
removing
the
top cover.
7-2
Advertisement
Table of Contents
