G.
Pulley Run Out Check:
Note:
A pulley runout check must be done with the pulley installed on the alternator. Consult the aircraft
and/or engine maintenance manuals for procedures to perform the pulley runout check while on
the aircraft engine. Do Not install alternator belt prior to checking pulley runout.
(1) Place the alternator in a secure fixture but take care not to damage the alternator body using a vice or
similar holding device. (May also be checked while mounted on the aircraft engine with belt removed if
space permits.)
(2) Install a dial indicator set up with the indicator measuring on the front face of the installed pulley.
Indicator must be capable of measuring 0.0005 inch or better.
(3) Install a dial indicator set up with the indicator measuring on the groove edge of the installed pulley.
Indicator must be capable of measuring 0.0005 inch or better.
(4) Zero out the indicator and slowly rotate the pulley for each axis runout check.
(a) ES-10024B-1, thru -4 and ES-14024B-1, -2, -5, and -1LS series pulley assemblies must not
exceed a runout of 0.008 inch on either axis.
(b) The ES-10024B-5 alternator (HET P/N 40840 pulley) must not exceed a runout of 0.006 inch on
either axis.
(c) The ES-14024B-1LS, ES-14024B-3, and ES-14024B-4 must not exceed pulley run-out tolerance
requirements of OEM.
5.3 Alternator Bench Testing
CAUTION
BEFORE BEGINNING THESE PROCEDURES, REFER TO
AND OBSERVE THE PRECAUTIONS LISTED ON PAGE 5-2
OF THIS SECTION. BENCH TEST PROCEDURES MUST BE
PERFORMED BY AN APPROPRIATELY RATED MECHANIC
IN AN ADEQUATELY EQUIPPED FACILITY.
A. Alternator Output Test Conditions
(1) The alternator is to be at room temperature (70-80 degrees Fahrenheit or 21-27 degrees Celsius)
before beginning the test.
(2) The alternator is to be connected so that it is supplying its own field current.
(3) The output is to be controlled by an adjustable load.
(4) The alternator is not to be run for longer than 30 seconds for each test point.
B. Ventilation
(1) Alternators not equipped with an external fan are cooled entirely by air pressure supplied to a SRE
air inlet. When bench testing this type of alternator, testing should be performed as short as possible
unless adequate air pressure for cooling is supplied. Adequate air pressure should be applied across
the unit and is considered to be at least 3” H2O delta pressure.
Aircraft Alternator
Maintenance Manual
24-30-01
ES1031
Page: 5-4 Rev.
B: 20 Apr. 2022
© 2022 - Hartzell Engine Technologies - All rights reserved
