Delco Remy Generators (& land/taxi/led lites)

[sreeves]

Does anyone know if it is legal to replace the 13 amp generator #1101876 with the 25 amp 1101879? Are the dimensions the same for both generators? Same total length and shaft length and shaft diameter? I can't find the physical specs anywhere.

[Bruce Fenstermacher]

Generators are the same other than their rating.

I had a 25 amp generator on my first 170. I never questioned its legality nor did anyone else. I seem to remember never finding anything that would document it specifically to be legal and I never found anything that indicated it would not be. If you have an undampened crank, which I did at the time, you are restricted to a 25 amp or less generator.

You need to change out your regulator to a 25 amp regulator should you upgrade otherwise your regulator will never ask the generator to put out more than 12 amps.

[sreeves]

Thanks, very good point on the regulator. I am thinking I would also need to increase the amperage of the generator fuse. Do you happen to know where I can get the higher amperage regulator or a part number?

[Bruce Fenstermacher]

I could come up with the part number of the 25 amp regulator. I'll have to dig. Yes you need to make sure the fuse or breaker is sufficient and more important that the wire in the system is also sufficient. However I do not believe Cessna used different wire size over the years. I could be wrong.

[Bruce Fenstermacher]

From this thread and post from GAHORN

http://cessna170.org/forums/viewtopic.php?f=24&t=591

1118384 or VR-300-25 (25 Amp)

[sreeves]

OK, I'll check. I'm trying to decide if I should change this generator or go for the Plane Power Alternator conversion kit. While doing my research, I see on the Plane Power aircraft eligibility list that the 170, 170A, 170B are approved. But it includes a voltage regulator and the regulator eligibility list doesn't show the 170. Guess I should call them tomorrow and get the scoop.

[Bruce Fenstermacher]

Personally, I'd find a 35 amp generator and regulator and forget the Plane Power. I've seen to many (3) Plane Power alternators fail and I want nothing to do with them. With today's move to low power everything such as LEDs, there is no reason you need more that 35 amps.

Seems you might have a 25 amp generator. I'd install that and an appropriate regulator.

[sreeves]

Thanks for the info on the alternator. I hadn't heard of the poor reliability before. Good to know!

Actually, I was checking the part number on my installed generator today and it appears it is the 35 amp generator #1101898. But it doesn't put out anything near 35 amps. Perhaps because it is matched with the wrong regulator. Probably a 13 amp regulator. I'll check the regulator part number tomorrow to see. And I understand that the 35 amp generator can only be used with an engine with a dampened crank...whatever that means. I doubt if mine has a dampened crank. My engine data plate is very hard to read but I have been told that is one way to determine the dampened crank is to look for a "D" on the number. Any other ways you know of?


BTW, that generator has been on that engine for at least 10-15 years and working fine...Dampened crank or not, just won't put out enough juice.

So that is why I was asking about the 25 amp generator. It should supply plenty, even if I have to switch some lights out with PMAd leds. ($$$)

I also checked the Type Certificate and the best I can make out, it is supposed to be a 1101876 (13 amp) generator on the engine. That is why I was asking about the legality of using a different rated generator. Although as hard as it was for me to see the part number today with the generator installed, I doubt if anyone would ever check it. Like you said.

[Bruce Fenstermacher]

Actually your engine probably does have a dampened crank as undampened were only made in '48. Even so my '50 had the early crank.

How do you know your 35 amp gen won't put out 35 amps? Have you tried to turn on that much load and it won't keep up?

If it won't, the regulator is the first place to go and be sure it is correct.

I have two friends who between them have had three plane power alternators fail with less than 500 hours on them. Much less. My one friend is on his third, the first two with less than 100 hours each.

[n3833v]

You can check the generator output by grounding the field terminal to the generator and read with an amp meter to see the amp output into a load.

John

[sreeves]

I have tried putting a load on the system and the CB pops. I will check the regulator part number and CB rating today and get back to you guys tonight. And I am leaning towards the regulator being of the wrong rating. I am betting that if I can find a 25 or 35 amp regulator and the proper size CB, I will have plenty of juice. Of course I am usually wrong!

Steve

[sreeves]

OK guys, here is the latest info on my generator saga.

1) It appears I do indeed have an engine with the dampened crank as the Serial number is 6022-D-1-2 and it is the original engine. So I guess the 35 amp generator is just fine for use on my engine.

2) I have a 20amp circuit breaker for the generator though I haven't seen anything close to 20 amps on my cockpit ammeter when the breaker pops. So I will be looking for a 35 amp breaker.

3) My voltage regulator currently installed is made by United Technologies Electro Systems. #RGS 12H 104. Trying to find some info on the rating of that regulator but having a hard time so far.

4) I found a 35 amp 14v Lamar regulator #VR300-14-35 on the quality aircraft accessories website, www.qaa.com . So is the consensus that I should buy that regulator ($275.00) and have it installed and after changing to a 35 amp CB to see if I get more juice?

5) While looking at my current generator, I am reminded to ask about the blast tube. Looks like all the delco generators have that shroud that includes the blast tube. Mine isn't hooked up to any ducting. Do any of you have a ducting hooked up to that blast tube? BTW, my problem hasn't occurred because of any generator temp problems. I can start the airplane up and turn everything on and the CB will pop right away. No difference when the generator has been running a long time.

[Bruce Fenstermacher]

DO NOT spend $275 just to find you have another problem and not the regulator at all.

OK now that I have that out. Let me think and I'll be back.

[sreeves]

OK

[sreeves]

Just called United Technologies to find out the specs for my currently installed regulator I mentioned above. No help. They couldn't even determine which department to transfer me to and the website doesn't provide that info either. So I still don't know the amperage output rating for my regulator.