2548H INSTRUCTION MANUAL
56-101-00420 Rev. C
Ch. 3
Nov
/
07
/
14
Page 18 of 33
5. INDIVIDUAL TANK UNIT INSULATION TEST
Caution: Empty and purge fuel tanks before performing the Tank Unit Insulation test.
Note: It may be necessary to set an aircraft tank selector switch to perform the desired
test. Refer to the appropriate Maintenance Manual for additional information.
(1) Configure the adapter cable and unit as shown in either Figure 8 or Figure 9.
Figure 8
INSULATION TEST, CONFIGURATION #3
Note: Adapter harnesses are available from this manufacturer for connecting to
certain aircraft equipped with probe system bulkhead connectors. The harness
has a switch for selecting each of the individual probes for insulation and
capacitance tests. It then connects directly to the test set receptacles for
resistance or capacitance testing as shown in Figure 9.
Figure 9 INSULATION TEST, CONFIGURATION #4
(2) Set the T/S TEST POINT switch to LO-Z/HI-Z.
(3) Place the Test Set’s ON/OFF switch to ON. (If the configuration used is in accordance
to Figure 9, also rotate the adapter’s Probe Selector switch to one of its positions.)
(4) Rotate the INS TEST POINTS selector switch to GND/SH.
