I just finished converting my coupe to the Cessna/Ford 60 amp alternator. I did it for many reasons, the foremost was because I had an old 10 amp generator that was toasted. I could not see spending money on a 1920's technology when there was available a far better option. I also converted to the solid state regulator at the same time. I am very pleased with the results. Now I have lots of charge power. It seems to take seconds to replace the power taken for a start, turn on everything in the panel and you still are charging, will charge plenty at idle for those long treks to the active, and will probable last far longer than any generator ever did. You can shave the cost some, a used or rebuilt can be acquired for far less than you quoted. Also, you don't really need the STC since it is an easy field approval item and is a bolt on replacement. A little rewiring is required to handle the 60 amps, also a new voltmeter/ammeter guage. Oh did I mention - less weight as well.
--- In [email protected], "dtaylor9319" <dtaylor9...@...> wrote: > > > > In my copy of Coupe Capers, I have seen for sale a kit to convert my existing > Delco Generator to a new fancy alternator. Cost is around $700. If I find > that my Delco 35 amp generator needs replacement, would there be any real > benefit, or problems with converting to an alternator. Up til now, everything > has been working fine, no radio problems or circuit breakers popping out, > lights working, no smoke in the cockpit. I would really rather stay with the > old generator if there will be little or no good to come of switching to an > alternator. Is the 35 amps the generator enough? I would think the alternator > would produce 50 amps at least, but do I really need that much. > > --- In [email protected], Iflysmodel@ wrote: > > > > Hey DTaylor: I am no expert, but here are some of the things to check/try: > > It is very easy to test the generator on the plane. The test is > > definitive. > > > > Disconnect the ground from the battery. Remove all the wires from the > > generator. Connect a volt meter between the armature of the generator and > > the generator case (ground). Connect a jumper wire from the field terminal > > to the generator case. Start the engine. Voltage should track RPM's and > > reach 13-14 volts by the time you get to about 1500 RPM (probably sooner). > > If this test fails connect the volt meter from the field terminal to ground > > and repeat. If you get a volt or two, the generator is bad. If you get > > nothing flash the field then repeat the first test. > > > > Troubleshooting Alternator and Generator Issues: > > > > > > DC Charging systems can be identified as "A" or "B" circuit. It is > > necessary for the technician to determine > > which system he has in order to properly troubleshoot. The "A" system > > controls the output by regulating the > > field circuit to ground. The "B" circuit controls the output by > > regulating > > the battery to field. > > > > All Delco Remy Generator charging systems are "A" circuit, therefore their > > regulator controlled how much > > ground was placed on the generator field circuit. This was originally > > accomplished by a vibrating point system > > in the voltage regulator. The more the points were vibrating toward the > > closed position the more the output. > > The further apart the points were during the vibrating function, the less > > the output. > > > > The solid state generator controls work by controlling the generator field > > to ground through a system of > > electronic components rather than the vibrating points. The theory > > remains > > the same, the more ground on > > the generator field, the more output and vice versa. > > > > Most general aviation alternators are "B" circuit. In order for them to > > output current from the alternator, > > battery must be applied to the field. The more battery to field, the > > higher > > the output. The regulator is then > > assigned the task of controlling the amount of battery to field. There > > are > > some general aviation charging > > systems that are of the "A" circuit type. These are normally found in > > Prestolite alternator systems with two > > field terminals on the alternator. If neither of the fields is grounded > > to > > the frame of the alternator, then > > the system is "A" circuit. This simply means that the voltage regulator > > is > > controlling the alternator field > > to ground to control output. > > > > The reason it is important for the technician to determine whether the > > system is of the "A" or "B" style is so > > that they can proceed to diagnose the system. A common method of > > diagnosing > > charging system problems begins > > with the full field test. This test is used as a method of determining > > whether the generator or alternator is > > functioning. Since the regulator controls how much battery or ground is > > being applied to the generator or > > alternator, the full field test requires bypassing the regulator and > > jumping full ground or battery to the > > field circuit. This causes the generator or alternator to charge at full > > output when rotated at cruise RPM. > > > > If you are testing a Delco Remy Generator system, remove both the armature > > and field wires from the generator. > > To prevent damage, cover the wire ends with tape. Next, jump the field > > post > > on the generator to a good airframe > > ground. Connect a DC voltmeter to the generator armature terminal. > > Connect > > the plus side to the post and the negative > > side of the meter to ground. With the field grounded the generator, if > > good, will generate a voltage on the armature > > terminal. The voltmeter should follow the throttle. The more engine > > speed > > the more output. Using a digital meter in > > this application is sometimes not effective. An analog (needle movement) > > meter is much more reliable. > > > > Should you have a Generator that is not Delco, it could possibly be of > > the > > "B" circuit, Field to Battery, type > > application. If so, follow the instructions in the previous paragraph, > > except connect the jumper from the Armature to > > the Field post. Then connect the meter from the armature post to ground > > and measure the output voltage. Normally, > > the generators manufactured by Bendix, General Electric and Leece Neville, > > > > adopted the "B" circuit method. > > > > When testing general aviation alternators, the brands encountered will be > > Ford, usually found on Cessna and Chrysler > > on most older Pipers. You might also run across Delco Alternators on > > various models of Piper and Beech aircraft. > > Motorola units, in the form of STC approvals by Alcor or InterAv, must > > also > > be taken into consideration. All of these > > unit are "B" circuit requiring a jumper from the Battery post to the > > field > > post in order to "full field". This means > > you must remove the field wire, tape the terminal for protection, and > > connect a jumper from the large output terminal > > over to the field post. Connect your DC voltmeter from the output > > terminal > > to ground and the voltage should then follow > > the RPM if the alternator is good. > > > > In the instances where you have a Prestolite charging system, you must > > first determine whether the system is "A" or > > "B" circuit. If the alternator has only one field post it is "B" circuit > > and requires jumping battery to field. If > > the unit has two field post, normally f1 and f2, disconnect both field > > wires and protect. Now connect one jumper from > > the Battery output post to one field post and a second jumper from the > > remaining field post to ground. This will full > > field the dual field models. The voltmeter is connected from the Output > > post to ground as in the previous example. > > > > If the generator or alternator passes the full field test the next most > > likely culprit is the voltage regulator. A > > fairly reliable quick test is to connect your voltmeter to the wire > > delivering battery to the regulator from the bus. > > This should read battery voltage, either 12 or 24 volts depending on the > > system. If you are getting good input voltage > > to the regulator, connect your voltmeter to the field circuit exiting the > > regulator. You should read some amount of > > voltage. If the reading is zero the voltage regulator is probably > > defective. > > > > Before replacing the regulator it is always a good idea to measure the > > resistance of the field circuit. This can be > > done at the regulator field wire or on the field post of the generator or > > alternator. The normal reading from the > > field post on 12 volt systems is 4 to 6 ohms. On 24 volt systems this > > doubles to 8 to 12 ohms. This can vary slightly > > and still be considered normal. > > > > > > > > In a message dated 7/12/2010 4:32:22 P.M. Eastern Daylight Time, > > dtaylor9319@ writes: > > > > > > > > > > Went to fly Saturday morning and found a sharp discharge on the Amp Meter > > when electronic circuits were turned on. Ran up to 2100RPM with nothing on > > but the radio and got no positive indication. Where do you start to sort > > out > > what the source of the problem is. Cigarette lighter plug in voltmeter > > shows 11.2 volts. 1966 Alon Aircoupe with a C90 16F. Has generator not > > alternator system. > > >
