Electrical system Flashcards
What is the purpose of the EXT PWR annunciator?
The amber external power annunciator light will illuminate when auxiliary power unit is plugged into the external power receptacle with the external power switch on and bust ties relays closed, power is applied to both generator buses, battery, and triple fed bus the entire aircraft electrical system is activated.
The EXT PWR annunciator light will flash when battery power is applied, external power connected, but not turned on, and voltage of the power unit is between 25 to 32VDC. The annunciator will then remain steady once switched on.
What are the external power limits?
External power carts will be sent to 28.0 to 28.4 V and be capable of generating a minimum of 1000 A momentarily and 3000 A continuously.
What are the generator limits?
In flight limits are 100% generator load and a minimum N1 of 85%.
During ground operation, observe the following limits:
0 to 50% generator load-/minimum N1 51%
50 to 80% generator load/minimum N1 61%
80 to 85% generator load/minimum N1 70%
Starter limits
Use of the starter is limited to:
40 seconds on, 60 seconds off.
40 seconds on, 60 seconds off.
40 seconds on then 30 minutes off.
