Electrical System - Piper PA-44-180 Seminole 1979 Pilot's Operating Handbook And Faa Approved Airplane Flight Manual

SECTION 7
DESCRIPTION & OPERATION
OFF position shuts off the fuel now to that engine.
When one engine is inoperative and the fuel
selector for the operating engine is on X FEED
the selector for the inoperative engine must be in
the OFF position. Do not operate with both fuel
selectors on X FEED except as required in the
WARM-UP checklist. Do not take off or land
with a selector on X FEED.
Before each night, fuel must be drained from the low points in the fuel
system to ensure that any accumulation of moisture or sediment is removed
from the system. A fuel drain is provided for each half of the fuel system.
The fuel drains are located on the right side of the fuselage just forward of
the entrance step. (Refer to fuel draining procedure in paragraph 8.21, Fuel
System.)

7.17 ELECTRICAL SySTEM

The electrical system is capable of supplying sufficient current for
complete night IFR equipment. Electrical power is supplied by two 60 ampere
alternators (Figure 7-15), one mounted on each engine. A 35 ampere-hour,
12-volt battery provides current for starting, for use of electrical equipment
when the engines are not running, and for a source of stored electrical power to
back up the alternator output. The battery, which is located in the nose section
is normally kept charged by the alternators. If it becomes necessary to charge
the battery, it should be removed from the airplane.
Two solid state voltage regulators maintain effective load sharing while
regulating electrical system bus voltage to 14-volts. An overvoltage relay in
each alternator circuit prevents damage to electrical and avionics equipment
by taking an alternator off the line if its output exceeds 17-volts. If this should
occur, the alternator light on the annunciator panel will illuminate. Voltage
regulators and overvoltage relays are located in the nose section.
REPORT: VB-860
7-16
PIPER AIRCRAFT CORPORATION
NOTE
ISSUED: MARCH 23, 1978
REVISED: OCTOBER 11, 2011
PA-44-180, SEMINOLE