Alternator Problems

7/27/2019 Alternator Problems

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Recip Technology

April 2001 Aircraft Maintenance Technology www.AMTonline.com

If you've ever had an out-of-box failure of a replacement alternatorthen you need no description of the frustration you felt when that hap-pened. If you havent had that experience then no description will do itjustice. Technical Reps and Warranty Administrators develop this same

sense of frustration when a returned out-of-box failure unit tests to spec-

ifications.

Aircraft charging systems occasionally present a real troubleshootingchallenge. As Tech Service Reps, we would like to minimize your frustra-

tion and ours by offering the following insights for solving commonly

encountered problems. Given the complexity of the charging system, the

information presented in this article will be necessarily brief. We will focus on

the high spots of alternator troubleshooting. Other related components

and some of their effects will also be addressed.

Throughout the years, weve received numerous calls requesting tech-

nical assistance with charging system problems. About the time we think

we have heard it all something new comes along. The old adage that

You can never know it all certainly applies to alternators! The only

consistent factor is that two basic scenarios exist. The first scenario is

It was working OK and now it isnt, and the second scenario is I just

installed it and it doesnt work. This second scenario can be muchmore insidious and difficult to troubleshoot, especially if you are

uncertain as to the failure mode that caused you to change the

component in the first place.

At a risk of pointing out the obvious, your first step should always

be to verify that the alternator was correctly installed. Is everything

properly routed and secure? With belt-driven units, is the belt tension

proper? These questions and others equally apply to units that fail soon

after installation.

If all else fails, read the directionsManufacturers frequently include installation instructions and some even

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By Winston Greer & Mike McC luskey of Kelly Aerospace Powe r Systems.


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Recip Technology

February 2001Aircraft Maintenance Technology www.AMTonline.com2

include a test report packaged with the unit. Occasionally,

parts dispatchers remove this information so as to include

them in the customers file. Sometimes these papers actually

end up being discarded with the thought of helping the

mechanic by removing extraneous tags, etc. If you deal with a

dispatcher in your organization, ask if you can look over any

information that came with the unit. If a manufacturers bench

test report shows that the unit came off their production lineoperating properly, then its not likely any fault lies with the

replacement unit. If you are the one who actually opened the

box and you are sure there are no directions or test reports

included, look for other contact information such as the man-

ufacturers telephone or fax number on the box or data plate,

even a web site or email address. In many cases, the manufac-

turer has a toll-free number to call for technical assistance.

Spend a few moments reviewing installation instructions

and performance criteria (see Figure 1). This exercise may pre-

vent you from removing a good replacement unit and

installing yet another potentially misdiagnosed out-of-box

failure. Confirming how the installation is to be performed

correctly,either through written instructions or with coachingby a Technical Service Representative, can likely save you that

out-of-box failureexperience and get your customer back in

the air sooner.

Systemsimilarities & differencesThere are three basic types of alternators used on general

aviation aircraft: the Ford style, the Chrysler style, and the

Prestolite style. The basic principle remains the same for all

three models: the alternators job is to produce AC and con-

vert it to direct electrical current before leaving the device. In

so doing, the alternator provides the direct current required by

the aircraft instrumentation and equipment.

Distinctions between these models are minor. The great-

est difference lies in the wiring configuration of the voltage

regulator and the alternator. In some installations, the current-

controlling element of the voltage regulator is in series

between the A/C bus (direct current) and the alternator field

(F1). Only one field terminal will appear on the back of the

alternator, with another being internally grounded.

Alternators with single-lead brush racks will always be wired in

this manner. In other installations, the current-controlling ele-

ment is located between the alternator field (F2) and ground.

In these installations, the alternator will have two field termi-

nal connections available. Alternators with two-lead brushracks can be wired either way.

Grounding of field terminalsOne common technical assistance request is diagnosing a

newly installed alternator that doesnt work. Most Prestolite-

style alternators have two field terminals: one must be

grounded directly or through the regulator. Some airframe

manufacturers install a very small metal tab going from the F2

terminal to the brush holder screw. Better look close, though;

given a well-used alternator, if you dont know its there, youll

never see it (see Figure 2).

Identifying the failure mode/isolating the causeNow back to the first scenario: The alternator was work-

ing OK and now it isnt.Presuming that an alternator bearing

failure is not involved, that connections all check OK, and cor-

rect belt tension has been confirmed for those belt-driven

Its w ell know n that charging system components can affect radio com-

munication in the form of noise. Failing diodes or a bad stator w ill normal-

ly generate a whine i n the headset that w ill vary in pitch w ith the R.P.M . of

the engine. Radio noise falsely attri buted to leaking diodes or a partial shortin the stator can be one of t he hardest problems to track down and solve.

Given a new manifestation of radio noise, one of the easier checks is for

alternator wires situated too close to the antenna cables. Alternators inher-

ently make some electrical noise and if w iring has recently been re-routed

too close to antenna cables, the radio will pick it up. If you have shielded

w iring going to or from t he alternator, make sure both ends of the shield are

properly grounded and that you have good continuity to the airframe. Its

also advisable to inspect the connections at the batt ery. These connections

should be perfectly clean, bright and tight. Often overlooked is the connec-

tion of the ground strap from the engine to the engine mount. These con-

nections tend to corrode over time and you cannot see t he corrosion w ith-

out taking the ground strap off. If both ends of the connection are clean and

tight and the problem persists, then unfortunately everything else has to be

checked. Be certain to look closely before deciding all is OK; the problem of

corrosion can be very subtle. It only takes about 0.2 ohms resistance on theground plane to cause radio noise (and a variety of ot her problems). A friend

had an older airplane wit h the battery mounted in the rear. He had radio

noise, slow cranking R.P.M ., apparent alternat or problems, and several other

electrical problems. It was recommended that he run a dedicated ground

w ire from the battery to the firew all. W hen he did, all his electrical prob-

lems w ent aw ay. Over the years, the aluminum skin of the aircraft had oxi-

dized w here it w as overlapped and riveted, putting too much resistance in

his ground plane. Regrettably, all solutions are not this simple. Once all

potential sources of radio noise have been investigated and eliminated, you

may have a genuine avionics problem. Your local avionics shop wil l have to

be consulted for further investigation and diagnosis.

Radio Noise

Figure 1:Technical

documenta-tion a valu-able source ofinstruction,product per-formancedata, and

manufactur-ers contact

information.


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units, then use your

multimeter to check and

see if there is resistance on

the alternator field. If the field is

open, then the culprit is a bad rotor or brushes. If the

field checks OK (generally 3 to 25 ohms), the next step

would be to make sure voltage is getting to the field. If

not, then its the regulator or the wiring. Determine

whether or not voltage is getting to the regulator; if so,

then the regulator most probably is the culprit. If every-thing is checking as it should, by default, things continue

pointing to the alternator as the source of the trouble.

There is one more test to make before you remove it from

the engine use an analog ohmmeter to check the

resistance between the output terminal and ground (a

digital ohmmeter wont work). This is a reverse polarity

test so you have to ground the positive probe and contact

the negative probe on the terminal. The reading should

be between 30 and 50 ohms; a lower reading than this

indicates the stator or diodes are gone, and the alternator

must be repaired or replaced.

Low current outputThe next most common variant of the It was work-

ing OKscenario is low current output (this can cause a

technician to consider changing careers!). As with most

other problems, there can be several reasons for the

manifestation of low current output the most frequent

one being a shorted or burned stator.

A failed diode is the next most-common suspect

immediately following a suspected stator. With a failed

diode, you will likely experience radio noise. Modern

diodes are much more reliable and durable than those

used even just ten years ago, having a much higher

mean-time-to-failure life expectancy. Core unitsreturned to our shop have had the stator shorted and

burned with fully functional diodes; however, this is the

exception instead of the rule. The point is that diodes

today can handle the stress of stator failure better than

ever. Still, its not advisable to reuse diodes that have sur-

vived a stator failure due to induced stress, coupled with

a high probability of damage and subsequent loss of

durability.

Another possible cause of low current output is a

partially shorted rotor. In this case, the wires in the rotor

coil short to each other but not to ground. This lowers the

resistance of the coil, thus lowering the magnetic flux of

the rotor and the output of the alternator.

Brushes are yet another culprit that can certainly

contribute to low current output. Be certain to inspect

the brushes. Are they worn? Are they making positive

contact with the slip ring on the rotor? Most alternator

manuals give minimum lengths for brushes. If you hap-

pen to disassemble an alternator for any reason and itsbeen in service for a while, always measure the brushes.

For gear-driven alternators, the last and certainly

ugliest suspect for low output is the one that your cus-

tomer really doesn't want to hear about: The coupling

gear is slipping. As you may already know, the reason

your customer doesnt want to hear about this is that in

many cases, the replacement cost of a coupling gear is

two or three times the replacement cost of an alternator.

Coupling gears have rubber inserts that act as a torsion-

al buffer; the inserts are designed to shear to prevent

damage to the engine in case the alternator stops sud-

denly (for example, if something gets inside the alterna-

tor and locks it up). The rubber material of the inserttends to harden with age and heat and will eventually

allow the two halves of the gear to slip. A good indication

that the coupling gear is responsible for low alternator

output is when the system works fine with light electrical

loads but the amperage and/or the voltage starts drop-

ping as you add additional load. Engine manufacturers

service bulletins explain how to test coupling gears for

minimum slip torque. Also, if you are experiencing high

voltage with low output, this can be caused by leaky

switches and circuit breakers. If these components have

never been replaced, then now is the time to consider

doing so.

Pulsing ammeterAnother first scenario common complaint is an

oscillating or pulsing ammeter needle. Like all other

troubleshooting problems, knowing where to start look-

ing for solutions will conserve your time and temper.

Usually this problem is caused either by the field circuit

breaker, the alternator switch, or both. However, the reg-

ulator over voltage sensor might also be bad. To diagnose

the problem, turn the electrical system on without start-

ing the engine and measure the voltage coming off the

output terminal of the alternator. Next, measure the volt-

age on the input (power) wire of the regulator and com-pare the two readings. If there is

more than one-half (0.5) volt dif-

ference between these read-

ings, then, as you recall from

our earlier comments, either

(1) the circuit breaker is

Figure 2:Example of a

ground strap onthe field for a

Prestolite-stylealternator. These

can be easy tooverlook, per-

haps the reason a

mechanic hadmarked this one.

Figure 3: Just as overworn brakepads grind brake rotors, brushes

that have gone too long and beenworn too far cause irreparable

harm to mating slip rings.

www.AMTonline.comAircraft Maintenance Technology February 2001 3


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February 2001Aircraft Maintenance Technology www.AMTonline.com4

defective; (2) the alternator switch is

defective; or (3) the over voltage sensor

is bad. Note:You could have any combi-

nation of the three.At this point, check

the input voltage of the circuit breaker

and compare it with the output voltage.

Again, if there is more than one-half

volt difference, the circuit breaker mustbe replaced. Then perform the same

input-voltage versus output-voltage

test on the alternator switch. There

cannot be more than one-half volt dif-

ference or the switch must be replaced.

Voltage differences inside the switch or

circuit breaker originate at the con-

tacts. When they lose the dielectric

grease they are packed with, they arc

and pit and oxidize on the contact sur-

face. These compromised surfaces

eventually lose the ability to properly

conduct current. The outcome is very

much like magneto breaker points that

have been run a long time. Although it

is rare, one last possible cause of an

oscillating or pulsing ammeter is the

regulator itself. There are some early

regulator designs that operate on sucha low frequency that they will cause the

ammeter needle to pulse at low RPM

with a moderate load. If you have one

of these regulators you have two choic-

es: (1) live with it; or (2) upgrade to a

newer, high frequency regulator.

Nuisance trippingThe final problem well discuss

could fall in either of our two scenarios:

an alternator that drops off line for no

apparent reason. A simple cycling of

the alternator switch temporarily cor-

rects the problem. For obvious reasons,

this is frequently referred to as nui-

sance tripping. The first thing to

check for is a poor connec-

tion in the remote sense or

field wires. Some regula-tors are very sensitive

to ambient electrical

noise and any inter-

mittent condition will

cause the system to trip

off line. If connections

are confirmed as good

and the problem persists, then look at

the alternator itself. Even the slightest

scratch on the slip ring of the rotor can

cause nuisance tripping. Inspect the

brushes for excessive wear; especially

note if the copper wire is showing, andif it is then the brushes must be

replaced (see Figure 3). When the

brushes are too short, the brush spring

may no longer maintain proper pres-

sure for brushes-to-slip ring contact.

Before reassembly, the alternator slip

ring must be resurfaced. Dont ruin

your good work on the slip ring (see

Figure 4); use a piece of plastic or plas-

tic-insulated wire (you can even use a

toothpick) as a brush retainer in the

brush block (see Figure 5). Bare metal

wire can scratch the slip ring when its

pulled out of the brush block to release

the brushes once reassembly is com-

plete. It doesnt take very much arcing

between the brushes and the slip ring

to trip some systems off line and even a

tiny scratch can initiate or perpetuatethe dropping off line problem. If

youve looked at the alternator and are

confident that its not the source of the

problem, it is very probable that the

regulator overvoltage circuit or sepa-

rate overvoltage sensor is failing. Some

systems have no overvoltage protec-

tion at all, some have regulators with

overvoltage protection built in, and

others have a separate overvoltage sen-

sor. Make sure you know which you

have before replacing them.

This has been a very basic survey

of single engine electrical system trou-

bleshooting. Just remember one thing:

if you cant figure out whats wrong

dont hesitate to call a manufacturers

Technical Service Representative.

They probably can save your time

and frustration, your

customers money and

both you and your cus-

tomer a few gray hairs!

A M T

Figure 5: Insulated wire used as the brushretainer prior to re-installation of the

brush block. Bare wire can scratch the slipring when removed to release the brushes

Figure 6: One manufacturers technicalservice contact information.

Winston Greer is VicePresident of Qualityand Mike McCluskeyis a Technical Service

Representative forKelly Aerospace Power

Systems in FortDeposit, AL.

Figure 4: How your slip ring shouldlook when you are ready to reinstall the

rotor.

Reprinted with permission from

Aircraft Maintenance Technology, April

2001

KA40301


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September 2001 Aircraft Maintenance Technology www.AMTonline.com

Multi-engine alternator charging system troubleshooting

By Winston Greer and Mike McCluskey

M

ulti-engine electrical systems are nothing

more than single-engine systems coupled

together to make them work as a unit.

Continuing the treatment of alternator troubleshoot-ing from our initial article on this subject in the April

2001 issue of AMT, for this installment we will be dis-

cussing twin-engine applications.

If you are an optimist, then you might consider

twins an opportunity for:

1. Performance improvement

2. Increased safety through engine redundancy

3. Revenue-enhancement of your operation

If you are a pessimist, then you might think of

twins as just a way of doubling your problems.

Somewhere between these two extremes lies reality.

With more knowledge about troubleshooting twin-engine charging systems, you are more likely to adopt

a more optimistic perspective.

Basic theoryLets review the basics. An alternator is an electro-

mechanical device that converts mechanical energy to

electrical energy. A regulator is an elec-

tronic device that controls both the volt-

age and the field current of an alternator.

Fundamentally, all of this sounds quitesimple and it is, but interesting out-

comes can occur if everything is not

just right.Many of the topics covered

in this article are expansions on the

fundamentals discussed in the April

2001 installment, Taking Charge of

Alternator Problems. The funda-

mentals of troubleshooting single-

engine charging systems are the

same as those for troubleshooting

multi-engine applications.

However, significantdifferences do exist

between single

and multi-

engine appli-

cations. This

expanded

12


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www.AMTonline.comAircraft Maintenance TechnologySeptember 2001

treatment of the subject should

help to resolve some of the more

perplexing problems associated

with multi-engine alternator sys-

tems.

High Frequency RegulatorsRecently, the major reason forchanging regulator equipment is

to upgrade to newer designs that

operate at a higher frequency than

earlier designs. Higher frequency

(faster) regulators tend to elimi-

nate the wagging needle on

ammeters that earlier-designed

regulators were prone to cause.

These older regulators generally

operate at a frequency close to the

alternator frequency. As a result,the regulator tries to follow the

alternator and vice versa, causing

the pulsing or wagging of the

ammeter indicator. Another major

reason for changing to newer-

design regulator equipment is the

advantage of built-in ground-fault

protection. From a cost-to-benefit

ratio standpoint, this is one of the

great newer developments in regu-

lator design. With earlier-designed

regulators, a short in the alternatorfield would blow the regulator.

With ground-fault protected regu-

lators, the regulator is not dam-

aged, and an LED comes on to

alert of the ground-fault condition.

This is also a great diagnostic tool.

If an alternator keeps dropping off-

line and the LED comes on, then

you know the failure mode is the

field circuit. This feature saves a lot

of time (and money) when a

ground-fault problem occurs.Some technicians keep this type of

regulator in their toolbox and uti-

lize it as a diagnostic instrument

when the airplane they are work-

ing on doesnt have the newer-

design type of regulator.

ParallelingParalleling remains the most

challenging aspects of installing

alternators or regulators in twin-

engine applications, and it is herewhere those interesting out-

comesmight first become appar-

ent. An airframe manual will, in

most cases, give you instructions

on the proper procedures to follow.

Electrosystems Paralleling Proced-

ure Service Instruction SI-0101 may

also prove helpful, especially if the

aircraft electrical system has been

upgraded.

One circumstance that occurs

with increasing regularity is theinstallation of regulators that are

not original equipment for that

particular aircraft. In this case, the

manufacturer would have includ-

ed regulator-specific paralleling

instructions and may differ from

the original equipment regulator

paralleling instructions outlined in

the aircraft manual. These instruc-

tions are specific to the initial

installation, and may differ from

those supplied by a different regu-lator manufacturer.

In most cases, when upgrad-

ing to the new, high frequency reg-

ulators, they must be replaced in

pairs to allow for the units to talk

to each other. If you replace the old

style Linear regulator with the new

style high frequency switching reg-

ulator the units wont talk to each

other and paralleling the system

will be virtually impossible.

SystemoutputimbalanceAlthough single-engine trou-

bleshooting tips apply easily to

multi-engine applications, multi-

engine systems can present a host

of unique challenges. Always

remember to start with the obvi-

ous solutions: make certain that

the alternators on both engines are

properly installed, the wiring is

properly connected and routed,

the belt-tension is appropriate forbelt-driven units, the battery is

adequately charged, etc. However,

many pilots and mechanics think

that after paralleling is complete,

both alternators should produce

13

Recip Technology

ALU-8521L ALT.

ALU-8521R ALT.

F2F1

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VR286 (28V) VR286 (28V)

AIRCRAFT BUS

24-VOLT FIELD PARALLELING SYSTEM

OS75-28(over voltage

sensor)

OS75-28(over voltage

sensor)


7/8

exactly the same amount of cur-

rent on each side. This is not usual-

ly true. As much as 10 amperes dif-

ference may be normal. Many vari-

ables such as the wiring, the regu-

lators, the ground system and the

alternators themselves may con-

tribute to the imbalance between

the two sides. If the difference is

less than 15 percent (e.g., about 10amps for 70-amp alternators),

then searching for the cause may

require more time than you can

spare, in order to achieve very lit-

tle, if any, improvement.

Air gap differentialsIf imbalance in the two alter-

nators exceeds about 15 percent,

then improvement should be pos-

sible. Certainly, no two alternators

perform exactly alike this isespecially true in overhauled

units. Most of the components in

an overhauled unit have been

used at least once. These compo-

nents will, in most cases, have

wear differentials that contribute

to output imbalance. A good

example is the air gap between the

rotor and the stator, which may

cause a considerable difference in

the current output. All else being

equal, if one alternator has a0.010-inch air gap, and a second

has a 0.005-inch air gap, there will

be a noticeable difference in the

output, especially at low RPMs.

While the physics are not neces-

sarily intuitive, the effects of the

difference in the magnetic flux

producing the current vary expo-

nentially with distance. Simply

stated, doubling a difference in the

air gap of two alternators will

result in a rate of change greaterthan double that value. Just

remember that small differences

in air gaps can have a large effect

on output differences. When the

installation, or more likely the

customer requires a closely bal-

anced system the best option

may be to install new units

instead of overhauled ones. Eventhen, they will not likely produce

exactly the same output, though

the difference should go unno-

ticed.

Drive gears and beltsIn the case of gear-driven

alternators, serious imbalance

may be caused by the coupling

gears. If one coupling gear is slip-

ping, then the alternator may not

turn fast enough to produce thesame amount of current. There

are service bulletins addressing

this problem with detailed

instructions on how to properly

test the coupling gears. It is a

good idea to test the coupling

gear any time the alternator is

changed. These gears have rub-

ber inserts that tend to become

hard and brittle with age and

heat. Unfortunately, in most

cases the coupling gear costsmuch more than the alternator,

so be absolutely sure that it is

defective before you purchase a

new one. On belt-driven alterna-

tors, proper belt tension is very

important. Engine and alternator

manufacturers publish service

instructions on the proper ten-

sioning of the drive belts. To

ensure performance and reliabili-

ty, these service instructions

should be followed closely. If thealternator belt is too loose, it may

slip, and the alternator will not

turn at the speed necessary to pro-

duce the required output under

load. If the belt is too tight, it may

cause bearing failure.

Wiring, Terminals, andConnectors

As previously mentioned,

another unique challenge is prop-

erly maintaining the electrical sys-tem wiring. It doesnt require high-

er math to recognize that there

September 2001Aircraft Maintenance Technologywww.AMTonline.com14

If you have an aircraft that uses gen-

erators, then you might want to consider

converting to alternators with aSupplemental Type Certificate (STC). Since

most general aviation generators have not

been manufactured in over 30 years,

approved generator parts are getting hard-

er and harder find. In most cases, alterna-

tors weigh less than generators, and are

more reliable. Furthermore, in some cases,

it costs less to convert to alternat ors than to

have the generators overhauled.

When considering the conversion

from a generator system to an alternator

system, the first t hing to determine is w hatSTCs are available for your aircraft. One

good place to start looking is the FAA w eb-

site http://av-info.faa.gov/stc/ w here you

may search using many different parame-

ters.

STCs come in every conceivable form,

from paperwork-only where you obtain

the parts yourself and make the w iring har-

ness, to companies that provide the STC

and perform the installation. STC installa-

tions at the STC-holders facility are gener-

ally very good, and even more attractive if

you are close to one of their facilities and

convenience is the greater consideration.

But, getting an STC kit seems to bethe most popular option. There are many

compelling reasons for this popularity. A

good STC kit has everything needed for the

conversion including instructions, parts,

and required FAA paperwork; all you have

to provide for your customer is the installa-

tion labor. STC-holder installations may be

too expensive or located too far aw ay to be

convenient. With a paperwork-only STC,

you have to find the parts: alternators, cir-

cuit breakers, switches, wire, brackets, pul-

leys, etc. Then you must make the harness,and perform the installation. It is not a good

idea to merely add the extra w ires required

for the conversion; the old wires probably

have insulation that is hard and cracking

and could cause new problems in a rela-

tively short period of time. In fact, old w iring

alone in some cases might be j ustification

enough to perform a conversion.

No matter which option you choose,

you can know that your electrical system is

up-to-date, with parts and service more

readily available.

Generator to A lternator C onversions


8/8

may be at least twice as much electrical wiring in a

twin-engine system as there is for a single-engine sys-

tem. This means, of course, that there are more areas

where insulation can become chafed, and more poten-

tial for connectors to loosen and/or corrode. Make

sure that the terminal ends are clean and tight and that

there are no broken wires or wiring with chafed insula-tion. Good luck this can often be like finding the

proverbial needle in the haystack.

Ground systemproblemsAs we noted in the April 2001 AMTRadio Noise

sidebar, the ground system can present some of the

most serious troubleshooting challenges. Many techni-

cians change alternators, regulators, wiring and other

charging system components only to find that the air-

craft has a bad ground system. If you have more than

0.2 ohms resistance in the ground system from either

of the alternators to battery ground, it is time to startcleaning connections. Recall that other usual sus-

pectsof a bad ground can be the field circuit breakers

or alternator switches. To troubleshoot this, measure

the voltage at the bus bar with the system turned on

and the engines not running, then check the voltage

going into the regulator. If any breaker or switch has

more than a 1/2-volt difference from the input side to

the output side, then it is probably defective, and

should be replaced. To determine which one, you will

have to go directly to the switches or circuit breakers.

Anomalies associated with temperaturevariationsAnother consideration in setting up the alterna-

tors is temperature.

Alternator current is

inversely proportional to

temperature; that is, output

decreases as alternator

temperature increases. You

might have two alternatorsperfectly paralleled when

cold, but after they warm

up they become unaccept-

ably out of balance. Have

the pilot verify the balance

on the first flight after an

alternator is replaced or

reinstalled; you may have to

adjust the system when the

plane returns.

Some regulator models

are also more heat-sensitivethan others. The installa-

tion location of the regula-

tors might also increase (or

decrease) this effect. Some

regulators even require a

heat sink to dissipate the heat that they generate, so

(once again pointing out the obvious) be sure to read

the manufacturers' instructions. If you dont have suf-

ficient information, dont hesitate to call the manufac-

turer for technical assistance.

When aircraft charging systems go wrong, it can

be tempting to look at the situation from the bad sideand get frustrated. But bad perspectives can result in

bad outcomes. Hopefully these articles on charging

system troubleshooting have provided information

that can help keep your perspective optimistic. Here's

to your successful outcomes. A M T

Winston Greer is Vice President of Quality and MikeMcCluskey is a Technical Service Representative forKelly Aerospace Power Systems in Fort Deposit, AL.

Recip Technology

www.AMTonline.comAircraft Maintenance TechnologySeptember 2001 15

Paralleling remains the most challenging aspects of installing alternators or regulatorsin twin-engine applications.

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Aerospace

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Additional resources....

Kelly Aerospace Power Systems Product Support(888)-461-6077

The Source

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Alternator Problems

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Transcript of Alternator Problems