TM 1-1520-238-T-7
10–158
Change 8
10–48. FUEL QUANTITY SYSTEM – CAPACITANCE AND INDICATING TEST (cont)
10–48
(USING TF-579 TEST SET)
Task
Result
NOTE
If adjusted capacitance value is excessive, the helicopter fuel system
wire harness or connector pins may require replacement.
For older model aircraft the foward tank (tank 1) capacitance tolerance
may be increased to 1.0 pf.
k. Fuel quantity test set (fig. 10–70)
CAPACITANCE INDICATOR should
indicate 66.30 0.8 pf when TANK 1 adapter
tank loop capacitance value recorded during
fuel quantity test set calibration is subtracted
from actual indication.
If adjusted capacitance value is not within required
tolerance, go to paragraph 10–65.
Example:
70.2 pf
Actual indication on CAPACITANCE INDICATOR
- 4.1 pf
TANK 1 adapter tank loop capacitance
66.1 pf
Adjusted value
l. On harness adapter (fig. 10–68), set TANK
SELECT switch to TANK 2.
NOTE
For older model aircraft the aft tank (tank 2) capacitance tolerance may be
increased to 1.5 pf.
m. Fuel quantity test set CAPACITANCE
INDICATOR should indicate 91.0 1.0 pf
when capacitance value recorded during
fuel quantity test set calibration is subtracted
from actual indication.
If adjusted capacitance value is not within required
tolerance, go to paragraph 10–66.
n. On fuel quantity test set, set ON/OFF
power switch to OFF.
o. On pilot ELEC PWR panel (fig. 10–69), set
BATT/EXT PWR switch to OFF.
p. Detach harness adapter from FSC and
reconnect P937.
q. On pilot ELEC PWR panel, set BATT/EXT
PWR switch to EXT PWR.
