Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 223 / 881

4 . With the connections made as shown in Figure 24-5, start the engine and adjust its speed to
a p p r o x imately 920 to 1,250 RPM to obtain 3,000 to 4,000 alternator rpm. Turn on accessories as
needed to establish a load of 10 to 15 amperes. Note that the battery charge current is indicated by the
ammeter. Therefore, the current value may change downward at the beginning of a test run. This will
be especially true if the battery was used for engine starting.
5. After five minutes operating time, check the regulator operating voltage as indicated by the voltmeter.
Refer to Alternator Service Test Specifications for correct operating voltage. The operating voltage is
shown for ambient temperature in which the regulator is operating.
6. If the voltmeter reading indicates that the operating voltage is not within limits, carefully insert a small
screwdriver ( Phillips #O) in the voltage adjustment access hole on top of the regulator and adjust
v o l tage adjustment slowly to obtain desired value. Before condemning the regulator, recheck the
a l t e rnator and the battery; making sure that they are in good condition. Recheck all circuit connections
and all wiring for unwanted resistance (voltage drop test). Recheck the voltmeter for accuracy and
repeat the entire operating test.
ADJUSTING LAMAR MODEL NO. B-00288-1 REGULATOR.
1. Lamar B-00288-1 regulators are normally used in parallel alternator systems of multi-engine aircraft.
Make final adjustment with the aircraft system in actual operation and with test equipment connected
as shown in Figure 24-6. The balance adjustment is made while operating only one engine, either left
or right. Stipulate engine to be operated to permit complete safe access to both regulators, so that they
may be adjusted while the engine is operating without danger to the technician. For purposes of
d i sc u ssion, the engine selected to be operated shall be designate as LEFT and the inoperative engine as
RIGHT.
Figure 24-6. Adjusting Lamar B-00288-1 Regulator
(S/N 44-7995001 thru 44-8195026 and all PA-44-180T’s)
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
24 -23-07
Page 24-19
Revised: June 20, 1995
1J7
BUS GND
REGULATOR
“B”
FIELD PAR
BUS GND
REGULATOR
“A”
FIELD PAR
NOTE:
THIS DIAGRAM SHOWS ONLY BASIC CONNECTIONS FOR
THE PURPOSE OF EXPLAINING ADJUSTMENT
PROCEDURE.
PRECISION V/M (INITIAL
SETTING POSITION)
O/V
O/V
FOR
ADJUSTMENT
DISCONNECT
PAR LEADS
V
V
2
2
1
1
ALT
“B”
ALT
“A”
CAUTION:
FIELD V/M CIRCUIT MUST
NEVER TOUCH GROUND
SUGGESTED METER
SIMPSON #260 OR
EQUIVILENT RANGE 0 - 50V
& 0 - 5V DC (FINAL
ADJUSTMENT POSITION)