8-8
Section 8: Model 9100 — Routine Maintenance and Test
Final Width = 215mm
8.2.4.5
Replacing I+ and I- Terminal Fuses
1. Access
a. Switch 9100 Power
OFF
and disconnect the line power
lead.
b. Remove the Top Cover
The side edges of the top cover are located in slots in both
side extrusions, and secured to the rear panel by two
screws. A solid plastic block protects each of the rear
corners.
To access the I+ and I- Terminal Fuses, remove the top
cover as follows:
i. Release the four screws securing the two rear-corner
blocks and remove the blocks.
ii. Release the two screws securing the top cover to the
rear panel.
iii. Pull the top cover to the rear to clear the front bezel,
then lift off to the rear.
c. Calibration Seal
Caution!
With the cover removed, a 'Calibration seal' can be seen
covering a countersunk screwhead on the left side of the
chassis assembly, at the top. This is one of the securing
screws for the top guard shield. The seal is set in position
following a calibration of the instrument, so that removal
of the guard shield can be detected.
The calibration seal must NOT be broken unless the
guard shield is to be removed for Authorized work inside
the chassis assembly. Removal of the guard shield will
compromise the traceable calibration of the instrument,
and a full recalibration of the 9100 will be required.
d. Locate the Fuses
The fuses are located at the left front of the top guard
shield, beneath the ribbon cable which links to the
Interconnection PCB on the rear panel, and protruding
through grommets in the guard shield (Fig 8.2.3).
Fig. 8.2.3 Location of I+ and I- Terminal Fuses
1A (F) IEC127/11
1.25A (F) UL198G
4A (F) IEC127/11
6A (F) UL198G
OUTPUT
FUSES
I- Terminal Fuse
Low Currents
I+ Terminal Fuse
High Currents
I+ Terminal Fuse
Low Currents
500mA (F) IEC127/11
700mA (F) UL198G