Piper PA-28-161, Maintenance Manual

Page: 295 / 1104

PIPER AIRCRAFT, INC.
PA-28-161, WARRIOR III
MAINTENANCE MANUAL
2E5
24-30-00 PAGE 13
Nov 30/06
3. Standby Alternator (Installed with Avidyne Entegra in S/N’s 2842257 & up.)
A. Description
The standby system provides 20 amps of power to support continued flight in the event of primary
alternator failure. It turns on automatically, annunciating its operation to the pilot through the panel
mounted annunciator which doubles as a standby alternator load monitor.
If the primary alternator fails in flight, the standby regulator will sense the drop in system voltage
and automatically activate the standby alternator. If the current requirement is over 20 amps when
the standby alternator is activated, the STBY ALT ON annunciator light will flash. Reducing the
current usage to 20 amps or less will cause the annunciator light to cease flashing and light
steadily. The pilot may choose which equipment he needs for the given flight conditions by simply
keeping the total load below the flashing point of the annunciator. This will reserve battery energy
for transient loads (gear, flaps, landing lights, etc.) during approach. Loads may be beyond the
flashing point of the annunciator light for up to five (5) minutes without damaging the standby
alternator.
The standby alternator is mounted on the vacuum pump drive of the engine accessory case. Panel
mounted equipment includes the addition of a STBY ALT ON light to the annunciator, a STBY ALT
rocker switch and three standard pull type circuit breakers (1 amp, 5 amp and 40 amp). The
regulator is mounted under the floor in the forward baggage compartment, right side.
See 39-20-00 for illustrated component locations and Chapter 91 for electrical schematics.
B. Troubleshooting
See Chart 4.