TB 9-6625-381-24
Table 5. Insulation Resistance (MEGOHMS X1 range)
Test
Total
instrument
applied resistance
(MΩ)
dial drum
indications
Min
Max
1.5
1.2
1.8
2
1.6
2.4
3
2.4
3.6
5
4.0
6.0
151
12.0
18.0
25
20.0
30.0
50
40.0
60.0
90
72.0
108.0
1Replace
decade resistor with resistance standard No. 3.
Table 6. Insulation Resistance (MEGOHMS X100 range)
Test instrument
Total applied resistance
(MΩ)
dial drum
indications
Min
Max
1.50
120
180
2.00
160
240
5.00
400
600
10.00
800
1200
b. Adjustments
(1) Remove dust cover from TI.
(2) Connect 200 MΩ terminals of resistance standard No. 4 to TI insulation
resistance binding posts.
(3) Set megohms range switch to MEGOHMS X100 and adjust DIAL CONTROL
for dial drum indication of 2.00 on range 1.
(4) Adjust R15 (fig. 2) to obtain same indication on TI meter with KEY switch
either operated or released (R).
11. Final Procedure
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.