Saturday, February 9, 2013

Left Wing Electrical Connector Completed

The two shielded cables being used for the navigation/strobe and landing lights were prepared by stripping off about 3 inches or so of the Tefzel insulation leaving the shield intact. The shielding was then loosened by pushing up on it so the three internal wires could be fished out through the shield at the point where the outer insulation was stripped away. The shielding is then pulled back and a heat shrink tube is used to identify and dress the end of cables.
                    Shielded cables fully prepared and labeled … ready for heat shrink to be placed over the shield wires.
                                    Using the heat gun to secure heat shrink over the cable’s shield wires.

In an effort to create consistency for wiring the additional left landing light, the choice was made to use the same wiring pins on the left wing’s electrical connector as called for wiring the right wing’s landing light. In addition to the steady on and pulse power, wig wag operation requires an additional wire to be run from the master output of one light to the slave input of the other light (think wig wag sync). Because a single right light is the typical instillation, the decision was made to establish that light as the master and wire the left light as the slave. Pin 3 was available on both wing’s electrical connectors, so it was chosen to connect the wire that needs to run from the right landing light’s master output to the slave input on the left light for wig wag operation. Bellow are the pin assignments that will be used for wiring the eight pin Amp connectors on both wings.

Left Wing Amp Connector                         Right Wing Amp Connector
Pin 1      Ground                                       Pin 1     Ground
Pin 2      Stall warning indicator                  Pin 2      Not used
Pin 3      Right master out to left slave in     Pin 3      Right master out to left slave in
Pin 4      Landing light power                      Pin 4      Landing light power
Pin 5      Wig wag power                            Pin 5      Wig wag power
Pin 6      Navigation light power                   Pin 6      Navigation light power
Pin 7      Strobe light sync                          Pin 7      Strobe light sync
Pin 8      Strobe light power                      Pin 8      Strobe light power

Once a wiring plan was made, the drawings were updated to reflect the additional wiring in the left wing. Connector assembly began by crimping pins onto the ends of all the wires using a ratcheting crimping tool with dies for open barrel connectors.
                                         Using the ratcheting crimping tool with dies for open barrel connectors
                                          to crimp the connector pins onto the ends of the wires.
           Left wing’s electrical connector with all wires in place ready to be secured onto the mounting standoffs.
                                                  Left wing’s electrical connector mounted onto the standoffs.

Still need to place small wire ties on the connector’s wires to give them more security. Unfortunately the wire ties in stock here were far larger than ideal, so a trip was made to Radio Shack to procure smaller ties for instillation later today. As for grounding, both cable’s shield wires will be brought together and crimped into a ring connector that will be grounded at the same point where the left wing electrical connector’s ground wire attaches … a nutplate. Grounding point is the screw hole with rivets on either side which can be seen in the bottom left of the above photo. To insure a good airframe ground ,the primer will be removed where the grounding hardware meets the rib’s web.