Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 425 / 1956

PAGE 9
Feb 28/07 2I3
24-30-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
B. Alternator Control Units (Voltage Regulators)
The system uses two Lamar B-00382-1 alternator control units (voltage regulators).
(1) Adjusting Voltage Regulator Units
The only adjustment necessary to maintain the alternator system is the adjustment of the
voltage control on the voltage control unit. A voltage of 28.8 Vdc is automatically maintained.
All other adjustments are made at the time of installation and need not be reset.
(2) Bench Tests (Lamar B-00382-1)
CAUTION: IN-AIRCRAFT TESTING WITH ALTERNATOR RUNNING IS NOT
RECOMMENDED. DO NOT BYPASS REGULATOR BUS TO FIELD AS A
MEANS OF CHECKING ALTERNATOR OR OVER VOLTAGE PROTECTION
WITH ALTERNATOR RUNNING.
(a) Set-up
1 Remove unit from aircraft.
2 Set up the following equipment as shown in Figure 2:
Power: Pure dc regulated power supply (A) 28.8V 5A
Adjustable 6-12V power supply (B) 0.05A
Resistors: R1 1
R2 650 fine adjustment
R3 7.2 dummy load 4A
Ammeter: 0-5A dc
Voltmeters: Precision meter between pins 1 and 8;
between pin 3 and power (B) ground;
50 MV precision meter between shunts at pins 6 and 7.
Switch: Between R1 and R2
Indicator: 28V light (Mazda #1829 or equivalent)
3 Set up load resistance as follows:
a Jumper pins 1 and 2.
b Set dummy load resistance for 4A 28.8V (approximately 7.2).
c Remove jumper.
(b) Voltage Regulator Test
1 Turn power off.
2 Mate unit with test connector.
3 Open switch #1.
4 Apply regulated power supply (A). Hold constant @ 28.8 V ± 0.025 V.
NOTE: Power supply should be adequate for load. If fluctuation occurs, assist with
28 V battery to stabilize current.
5 Allow unit a 2 minute warm up.
6 Reset adjustment on alternator control unit for 1.0 A field current.
7 Decrease power supply (A) to approximately 28.6 V until ammeter shows 3 A field
current.
8 Check alternator inoperative indicator by varying power supply (B) to 10.25 ± 0.75 V.