Maintenance 5
U1253B User’s and Service Guide 133
3 To test Fuse 1, place the tip of the test probe on the right half
of input terminal . Ensure that the probe tip
touches the metal inside the input terminal, as shown in
Figure 5- 7.
4 To test Fuse 2, place and touch the tip of the test probe on
the right half of input terminal . Ensure that the probe tip
touches the metal inside the input terminal.
5 Observe the reading on the instrument's display. Refer to
Table 1 below for the possible readings that could appear).
6 Replace the fuse when OL is displayed.
Table 5- 3 U1253B measurement readings for fuse checking
Current input
terminal
Fuse Fuse rating
Fuse OK
(approximately)
Replace fuse
Displayed readings
1 440 mA/1000 V 6.2 MΩ OL
2 11 A/1000 V 0.06 Ω OL