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.

L-1011 CPT Installation: AC Buildout - Power Buses - AC Tie Bus and Flight Station Buses

L-1011 Trainer - AC Tie Bus and AC Flight Station Buses

Slowly but surely the power distribution for the trainer is taking shape. Today we worked on the AC Tie bus and the AC Flight Station Buses. The image below shows the three AC Flight Station Buses. Each bus has a relay that is controlled from a "R" labeled circuit breaker on the CB3 panel. There is also a 120V relay that is for sensing voltage on the flight station bus to communicate to the computer as well as the annunciator on the Electric System panel.

L-1011 Trainer - Flight Station Buses

Another important AC bus component is the AC Tie bus. The tie bus is used to allow all AC sources to work together or to act as fail over for one another. Below is the AC Tie bus in the current build out phase. The bus has the relays for the three engine generators on the left together with one 120V relay used for sensing power on the bus. Eventually relays for External Power (Ground Power) and the APU simulation will be added.

L-1011 Trainer - AC Tie Bus

In additional to the work on the AC buses we also added a few more instruments to the flight engineer's instrument light bus. Below is how far we have gotten in bringing instruments onto the light bus.

L-1011 Trainer - Integral Instrument Lighting -  Continued

L-1011 Trainer - Integral Instrument Lighting - Continued