L-1011 CPT Installation: External Power and AC Tie Bus

L-1011 CPT - AC Tie Bus Relays

Today we installed the AC Tie Bus relays as well as the EXT PWR relay. The image above shows the AC Tie Bus control relays together with the APU, ENG1-3 and EXT PWR control relays prior to installation into the trainer.

The control relays are all Phoenix Contact 24V DC relays and in turn control the annunciator lights on the Electrical System panel as well as the the power relays in the DC/AC power distribution rack. Below is a short video of the operation of the External Power and the distribution of external power across the AC Tie Bus to the individual AC buses and the flight station power buses.

In case you don't want to watch the video. Here are a few still that first show the AC Tie Bus un-powered with AC External Power "AVAIL" (Available) but not ON.

L-1011 CPT - AC Tie Bus Open

Below the External Power is not switch onto the AC Tie Bus, the three Tie Bus Breakers are closed and AC BUS 1, 2 and 3 are now powered.

L-1011 CPT - Ac Tie Bus Closed and EXT Power ON

The lower FE/SO Station integral instruments light are powered by transformers connected the to AC Flight Station Bus 2. Int he picture below you can see that the instruments illuminate with External Power ON and only the AC BUS 2 tied to the AC Tie Bus.

L-1011 CPT - AC BUS2 Joined To Tie Bus Only

Below is a 2nd short video showing the operation of bringing AC BUS 2 online via the AC Tie bus only.