(b)
Splice the float switch electrical cable to the airplane wire harness with the applicable crimp tool (SWPM 20-30-12).
(c)
Put two layers of electrical splice tape over the splice to prevent damage from water and fuel.
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E. AIRPLANES WITH TYPE II FLOAT SWITCH; Center Tank Float Switch Installation Procedure (Fig. 403)
(1) Do these steps to install the liner (31) and the electrical cable (40) in the conduit (39):
WARNING: INSTALL A NEW LINER EVERY TIME THE CONDUIT IS REPLACED AND EVERY TIME THE FLOAT SWITCH IS REPLACED. THE LINER IS NECESSARY TO KEEP THE FLOAT SWITCH WIRING SAFE FROM CONTACT WITH FUEL. IF THE WIRING CONTACTS FUEL, INJURY TO PERSONS AND DAMAGE TO EQUIPMENT CAN OCCUR.
(a)
Put the installation tool into the non-ferrule end of the liner.
(b)
Attach a guide wire (10 feet or 3 meters in length) to the installation tool.
(c)
At the end of the conduit adjacent to the float switch, push the guide wire through the conduit until the guide wire comes out of the far end of the conduit at the front spar.
(d)
Insert the electrical cable for the float switch into the ferrule end of the liner until it touches the installation tool at the other end of the liner.
(e)
Put the liner and the float switch electrical cable into the open end of the conduit as a single unit.
NOTE: Loosen and turn the conduit tubes as necessary to insert the conduit liner and electrical cable.
(f)
Pull on the guide wire and push on the liner and electrical cable together.
(g)
Turn the liner as necessary to make it easier to put the liner and electrical cable into the conduit.
(h)
Continue to put the liner and electrical cable into the conduit until the liner adapter is seated inside the conduit.
(i)
Remove the installation tool and guide wire and discard them.
(j)
If you moved or turned any of the conduit tubs during the installation of the conduit liner and electrical cable, do these steps: 1) Tighten any conduit joints that you loosened to a torque of 266-294 inch-pounds
(30-33.2 Nm). 2) Loosen the conduit nut again to relax the torque. 3) The subsequent step must be witnessed and written in the maintenance
documentation for the airplane. 4) Tighten the conduit nut again to a final torque of 266-294 inch-pounds
(30-33.2 Nm). 5) Make sure the final torque is written in the maintenance records. 6) Put a lockwire on the conduit nuts that you tightened.
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May 01/03 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 28-21-71 Page 423
(2) Do these steps to trim and flare the end of the liner.
CAUTION: BE CAREFUL NOT TO DAMAGE THE ELECTRICAL CABLE IN THE CONDUIT WHILE YOU WORK WITH THE LINER. DAMAGE TO EQUIPMENT CAN OCCUR.
(a)
Hold the end of the liner that extends out of the front spar bulkhead union so the liner adapter is seated firmly in the conduit.
(b)
Pull the float switch electrical cable back out of the liner just enough so that the end of the electrical cable is inside the union.
(c)
Trim the liner at 90° to its center line so that 0.750 ± 0.125 inch (19 mm ± 3.17 mm) extends out of the union when the liner adapter is firmly seated inside the conduit.
(d)
With the tool 04E00063, flare the liner. 1) Form the cut end of the liner to accept the shoulder of the drain port assembly. 2) After you form the cut end of the tube assembly, the edge perimeter of the tube
assembly must be even to within ± 0.060 inch (± 1.5 mm)
(e)
Push the float switch electrical cable out past the trimmed end of the liner.
(f)
Pull any extra electrical cable out through the liner.
(3)
Install the float switch in the bracket with the float switch mounting nut (42) and washer(s) (41).
(a)
Permit the ground lug at the base of the float switch to turn to its natural position where the torsional load is at a minimum.
(b)
Make sure the float switch ground lug does not touch the float switch mounting bracket.
(c)
Tighten the float switch mounting nut (42) to a torque of 266-294 inch-pounds (30-33.2 Nm). 1) Do not let the float switch turn while you tighten the nut.
(4)
Do these steps to connect the conduit to the float switch with the float switch conduit captive nut (43).
(a)
Apply grease, VV-P-236, to the threads of the conduit captive nut.
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