Alternator upgrade
 

Is it possible, or advisable, to install a higher rated alternator when doing a replacement? In other words, if my front alternator is 38 amps, can I install a 60 amp rear alternator? Or must I do both at once?

Inquiring minds want to know!:o

I read some past threads and I now understand that the 60 amp alternators put more stress on the coupler. which is expensive when it breaks. I may just stay with the factory 38 amp rated alternators.

The Cessna 400 balanced regulator upgrade looks interesting. ;)

I'm considering dual PlanePower R1224s regulators. Looks like replacing the regulators with the R1224s eliminates the irksome diode assembly and alternator sensing circuit boards, and the overvolt sensor.

Plus side: solid state parallel load sharing & regulation & sensing in a fairly inexpensive unit (about $220 ea @ qaa.com). Appears the current annunciators for FRONT and REAR alt out can be used. Also likely eliminates the battery pack (so overvolt button and ALT reset button could be re-purposed for chem trails :eek: )

Downside: Might require STC (still researching approved models), certainly requires 337. If one goes offline, it stays offline and you finish the flight on 1 alternator. If both go offline, you finish the flight on battery.

Annual coming up this winter...if I can't get my circuit board and diodes all squared away, I might just rip it all out and put in the planepower regulators.

Someone also on this board re-build the circuit board & diode assy--might try that first--keeps the paperwork to a minimum.

My understanding is that Cessna Pilots Assoc. has a copy of the 337 paperwork that was approved for the regulator upgrade. You may have to join to get it though.

Has anyone installed these Plane-Power R1224 regulators and removed the diode laden 1960's designed board. If so what paperwork is required and where can I source it? I am a member at CPA and cannot locate any "337 Paperwork" there, Hard to search 337 as our plane keeps coming up too.

In either case I have been chasing ghosts and want to upgrade power system, seems to me that the removal of the old systems and replacement with up to date solid state design makes sense. Just need to stay legal...

Thoughts...Help...

You can't really get rid of the 1960's "diode laden" board, because it runs the idiot lights on the panel. What you CAN do is replace the regulators with true paralleling regulators that have wire(s) running between them to balance the load. The Cessna 400 series regulators have one wire that runs between them. These Plane-Power units appear to have two - look at the "Dual Alternator Only" inputs on it. There is a + and a - terminal.

The Plane-Power units are already STC'ed, so no 337 paperwork required. That is a plus*.

The wires from the original regulators are re-connected to the new regulators, so the install is very straightforward. The regulator mounting holes for the firewall are different, so most will fabricate a mounting plate out of aluminum to adapt. YMMV.

*EDIT - On further review, it appears a 337 form may still be required for the Plane Power regulators. My understanding now is that they would have to be "FAA-PMA" to NOT require a 337 form. Since they are only "STC", they DO require a 337, which requires a cooperative FSDO.

So these do not eliminate any of the other systems, just the regulators?

They don't eliminate the regulators, they replace them with better ones.

But yes, the rest of the system is unchanged. Dash warning lights still operate, no change to POH, etc.

Here is one of the causes of ongoing problems.

"The wires from the original regulators are re-connected to the new regulators..."

Many times old problems are just reconnected to new batteries, regulators, and alternators.

Dave

Very true, which is why I bought a couple of 400-series regulators to do the CPA upgrade to a true paralleling, load-sharing charging system!

I’m currently in a tech discussion over email with plane power folks on this very issue. The instructions say all the original circuit gadgetry is removed when R1224s go in. That includes the ALT restart circuit. Ultimately, new POH procedures are needed via supplement.

The R1224 appears on certain PMA paperwork, but no STC is published for the 337 type A6CE.

I’m also chasing ghosts and will be rebuilding the original circuit board And diodes this week.

I’ve been searching Cessna.org for more info on this “CPA upgrade”. Haven’t found a thing resembling official documentation. Can you please post the STC Or a Form337reference? Or directions to the place it resides? Much obliged for any words...