barfield 2548H, Instruction Supplement, Page: 3 / 7

61-101-00435.A1 June 22, 1999
PAGE 3 OF 7
2. SYSTEM INSULATION MEASUREMENT
1. Remove power from Aircraft Fuel Quantity System.
2. Defuel Aircraft as per Aircraft Maintenance Manual
instructions.
CAUTION: Observe all safety precautions.
3. Gain access to the Signal Conditioner.
4. Break electrical connection.
5. Connect the Adapter Harness A/C connector to mating Aircraft
wiring plug.
6. Do not connect the Adapter Harness to the Signal Conditioner.
7. Set the Test Set ON/OFF switch to ON.
8. Set the INS TEST POINTS switch to GND/SH.
9. Set the RANGE switch to X1.
10. Set the TEST FUNCTION switch to the INSULATION position.
11. Adjust the METER ADJUST to achieve an infinity indication on
the Test Set meter MEGOHM scale.
12. Set the Test Set ON/OFF switch to OFF.
13. Set the Adapter Harness IND. SELECT switch to A/C.
14. Connect the Adapter Harness HI-Z COAX and LO-Z TANK jacks to
the Test Set HI-Z COAX and LO-Z TANK insulation jacks using 2
each 101-01008 (BNC to BNC) cables.
15. Connect the GND jack of the Test Set to a good aircraft
ground using the 101-01007 cable.
16. Set the Test Set ON/OFF switch to ON.
17. Allow the Test Set time to stabilize.
18. Insulation shall not be less than value specified in Table 1.
┌──────┬─────────────┬────────────┐
│
TEST
│
TEST POINTS
│
INSULATION
│
╞══════╪═════════════╪════════════╡
│
1
│
GND / SH
│
1000 MEG
Ω │
│
2
│
GND / LO-Z
│
1000 MEG
Ω │
│
3
│
GND / HI-Z
│
1000 MEG
Ω │
│
4
│
SH / LO-Z
│
1000 MEG
Ω │
│
5
│
SH / HI-Z
│
1000 MEG
Ω │
│
6
│
LO-Z / HI-Z
│
1000 MEG
Ω │
└──────┴─────────────┴────────────┘
TABLE 1
19. Set the Test Set INS TEST POINTS switch for remaining Tests
per Table 1.
20. Insulation shall not be less than values specified in Table
1.
21. Set the Test Set ON/OFF switch to OFF.