Author Topic: 100 Amp Generator or 50 Amp Current limiter  (Read 5526 times)

rmartell

100 Amp Generator or 50 Amp Current limiter
« on: January 21, 2016, 09:06:55 AM »
While assembling #1295 we have come across a couple of items to consider.
It would appear that the original equipment list indicated a 100 Amp generator(24 volt) which was not part of the purchase. I was able to purchase a Leece Neville - M2 Generator (24 volt) but this one is only 50 amp.
To get us through the import process we were going to throw the 50 amp Generator (24 volt) on and worry about a possible alternator upgrade at some point later.
Here is the issue:
The system has the carbon pile regulator and Cut-out reverse current. My AME has reviewed the maintenance manuals (wiring diagram) and has asked me to source out a 50 Amp current limiter for system since we are installing the 50 Amp generator. This would appear to be the simple and most cost effective fix. Does anyone know where to obtain a 50 Amp current limiter?
The other alternative is to try and secure a 100 Amp/24 volt Generator with the 100 Amp current limiter?
Any suggestions would be appreciated.

Also, I guess I am in need of a vacuum pump for the GO480 G1D6 if anyone has a core or working unit.

Doug Johnson

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #1 on: January 21, 2016, 01:21:17 PM »
MY opinion Aircraft Spruce and specialty usually has everything you need.

I liked the Plane Power regular if you insist on a PMA approved regulator it has built in reverse current over voltage and over current and alternator fail light. I installed a electronics international voltmeter/ammeter so I could keep an eye on voltage certain conditions of low RPM where you shouldn't be operating a geared engine anyway you can get an over voltage condition with any regulator. Normally you will get a fail light.

I used a LR3C on my Helio they call it an alternator control system which has all of the above plus it is a linear voltage regulator and because of the way it charges it is much like your carbon pile regulator it has a battery temperature sensor and will actually extend the life of your battery and sealed RG batteries life is shortened with incorrect charging voltage.

Just looked it up on the internet. This is what they say

More than just another regulator. The LR3C Controller combines three essential devices in one physical container, making it a lightweight, space-saving, and cost-effective alternative for any aircraft electrical system, while also improving safety of flight. First, the LR3C operates as a “quiet,” linear regulator, generating no audio or radio noise (in contrast to switching-type regulators). Second, it provides a vital safeguard for your aircraft electrical system with a solid-state, “crowbar” over-voltage-protection circuit. And third, the LR3C Controller functions as an important low-voltage monitoring and warning system.

It is listed for experimental use but my avionics tech certified it with a log book entry for use on my Helio.

By the way most modern battery charging systems have a reverse current diode instead of reverse current relay this replacement can be certified by your Electronic Tech also.

carefully read this letter by Jim Weir posted before http://flyhelio.com/smf/index.php?topic=548.msg2944#msg2944
« Last Edit: January 21, 2016, 01:42:59 PM by Doug Johnson »
Doug

paullapoint

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #2 on: January 21, 2016, 06:01:57 PM »
You might try Zeftronics regulators. It is an electronic replacement for all that too and is Stc'd for most systems. I installed one on my Cessna and works great.  Paul

Doug Johnson

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #3 on: January 21, 2016, 07:43:11 PM »
I Just did a tutorial on linear voltage regulators vs. switching voltage regulators. In '94 I chose the linear voltage regulator because they are a little better in cold climates (AK) and early RG batteries which I was using were sensitive to charging voltage, since they aren't switching you don't get radio noise.

I went with the Lamar LR3C linear regulator over the zeftronics  LS-1A linear voltage regulator I think, for the temperature sensor which the zeftronic regulator now has also.

I suspect after reading the write up on the Zeftronics switching regulator, that now with more modern RG batteries the Zeftronics R25400 is a better choice plus it's PMA'ed.
Doug

jmetzler

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #4 on: January 23, 2016, 09:12:00 AM »
I believe Bob's issue is that he needs to be original for his Canadian import, then he'll look at 24 volt alternators after that. That's why he's looking for specific parts. Jim

jmetzler

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #5 on: January 23, 2016, 09:13:09 AM »
Bob, do you need a wet pump core? Jim

rmartell

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #6 on: January 27, 2016, 10:54:00 PM »
Doug,

Do you happen to have a surplus 24 volt, 100 amp generator? I believe you had indicated on an earlier post your mechanic was pounding your firewall to fit it.

Do you still have any of the old parts for that 100 amp generator system? If so, I would like to cross reference the part numbers on the carbon pile regulator, reverse cuurent cut-out, and the current limiter.

Does anyone in the Helio group happen to have any information as to the type and/or part number of the current limiter used in the 24 volt generator system used in the civilian or military planes, 50 amp or 100 amp?
Does anyone happen to have a picture of this elusive current limiter?
Does anyone have a civilian maintenance manual for the 295 electrical system to verify if it is different than the USAF & Army series maintenance manual?

Louis

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #7 on: January 28, 2016, 05:55:16 AM »

Does anyone happen to have a picture of this elusive current limiter?

My cowling is open.  If you can put a picture of what it should look like, il will be able to find it and put a picture of mine

rmartell

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #8 on: January 28, 2016, 09:39:17 AM »
Good Morning Louis,

I'm told it could look like an over voltage unit...may contain a small coil and contact.
Would it be possible for you to take a couple of photos...I believe between the generator on the firewall side, if you follow leads from the generator.

rmartell

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #9 on: January 28, 2016, 09:59:05 AM »
Louis,

You can send the photos to the email address on my profile - robert.martell@sigmarmackenzie.com

Doug Johnson

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #10 on: January 28, 2016, 10:07:58 AM »
Bob,
I don't have any parts left, the few I had were burnt up in a barn fire. I didn't keep the 100 amp gen and system. I was putting my Helio back together near Larmont aviation at Spartanburg at air park in Williamsport SC so I gave those parts back to Larry Montgomery.

When Larry passed on, I suspect those parts probably went to JAARS.

I Have been wracking my brain on the reverse current relay and cannot actually remember a reverse current relay.



here is the mil part and an alternate part #  for the 100 amp reverse current relay. I found nothing for a 50 amp reverse current but I suspect a 100 amp reverse current will block 50 amp just as well as 100 amp. Think heavy duty. Check out the alternate part number. It may lead you to a 50 amp reverse current, if you think you need it.

you really don't want a 24V 100 amp generator

I will send you the FAA files if you dont't have them already
« Last Edit: January 29, 2016, 12:56:07 AM by Doug Johnson »
Doug

airshiptv

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #11 on: January 28, 2016, 10:41:25 AM »
This is out of my area but if someone is pounding the firewall to get a 100 amp gen to fit, my guess is that there wasn't one there in the first place. so why do they need to do this?  For import into Canada?  I must be missing something.  Our U10 has a cutout, dished shaped, riveted in the firewall.  I always assumed it was for the 100 gen but there has always been a Jasco in our plane, even when we got it in 2000.

Doug Johnson

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #12 on: January 28, 2016, 11:45:13 AM »
I'll repeat the story we are talking about 2 different airplanes c/n 1233 came with a replacement military engine that had the 24 volt starter and generator only the military U-10Ds have the cutout in the firewall for the 100 amp generator. While installing the engine my mechanics discovered that the 100 amp gen was hitting the firewall one of my mechanics decided it was so close that if they put a dent in the firewall it would fit. The firewall was much stronger than he thought even though he was using a sledge hammer.

I was a little annoyed to say the least I could have put 12 volt accessories on the engine but that's when I converted to a 24V Jasco alternator because there are so many benefits to a 24 volt system. There was a president c/n 1232 had been converted to a 24 volt system.

The only problem you may run into is not having a 24 volt charger, when the battery runs down but even the military solved that by putting two 12 volt batteries in series.

Mainly that you get twice as many watts of output from the same amount of amps.
Doug

rmartell

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #13 on: January 28, 2016, 06:18:29 PM »
Hey Doug, thanks,,

Sorry to have beatin this issue, but I think Jim Metzler has figured out where we were going wrong. We only had the wiring diagram for the U10-A and U10B.
Apparently mine is the U10-D equivalent and covers #1295. So now we will start looking at the right maintenance manual which apparently does not show a current limiter.

An import into Canada creates an issue if the aircraft ventures away from the Standard equipment list - with the exception of an STC or SSTC (LSTC). 337's pose problems in Canada since field approvals arent necessarily accepted on face value. The odd exception is if the the part is FAA PMA or TSO'd and has an IA signature and a log book entry. Even then its a guessing game. With the import process, we try not to give the MD-M (Minister Designate - Maintenance) something to dig their teeth into.

Once the import is done, then we start looking replacing parts.

airshiptv

Re: 100 Amp Generator or 50 Amp Current limiter
« Reply #14 on: January 28, 2016, 08:34:51 PM »
Thanks for the info.  I get it now.