14 volt vs 28 volt electrical system

[togaflyer]

I was wondering which system most are installing in their RV 10's, 14 volt or a 28 volt system. Im leaning toward a 14 volt system since most modern electronics are pulling less current.

 

[Walt]

I was just thinking about this the other day as I work on quite a few certified aircraft with 28v systems.

There are a few advantages with 28v.
1: Smaller wire sizes = less weight.
2: Most avionics these days are rated from 11-33v. with a 28v system your "stuff" will keep working much longer after the alternator quits because you can have a 22v drop. With a 14v system you only have a short time before the voltage drops to under 11 and everything quits.

I'm not recomending you go 28v (not very common in the homebuilt world), only pointing out some of the "electrical" advantages.

 

[blahphish]

From my experience, albeit limited, I see mostly 14v in RVs. That shouldn't stop you from considering 28v though if you can pull it off

 

[Jesse]

Also, the flap motor and trims will need voltage converters because they are 14V only. You will also need a voltage convertor for any power receptacles. I have never seen a 28V RV, although there doubtless are a few. The benefits of 28V are nice, but in the opinion of most RV builders, apparently, not worth the hassle and/or cost.

 

[Neal@F14]

A difference to keep in mind is the availability of components.

This... it's pretty tough to find a 28V Nippon Denso alternator at your local AutoZone.

 

[9GT]

My original plan was 24 volts. In the end though I ended up swapping out all the $$ 24 volt stuff I purchased for 12 volt replacements to keep the electrical simplified. This topic has been talked about and debated ad nauseam on this forum and just about every aviation related forum I belong to. Check the archives and you will find plenty of reading/debates.

 

[togaflyer]

Sounds like a 14 volt system is the way to go. A 28 volt system may be more costly in the long run.

 

[flion]

I'm going to be devil's advocate here. For the record, I'm real happy with my 14V system in the RV-6A. But with the battery several feet behind the starter in my -10, I decided to go with the 28V system. My panel is Garmin 900X, so no problem there. The VP-200 runs my system and handles the trims, flaps, and 12 power outlets without problems. 28V interior lights came from Stein at the same cost as the 14V. Flightline sells the A/C in either 28 or 14 volts, no difference. B&C and Plane Power both have comparable alternators. Even the solenoids from Aircraft Spruce are not much different in cost. My ground power system is a little more expensive, but not hugely so, and the difference is mostly the amperage, not the voltage. So I'm not seeing a huge cost difference. True, I can't got to the auto parts store for everything, but I usually prefer higher quality stuff anyway. And I definitely think it's worth it to have a little more voltage running the starter from farther away on a bigger engine. Just my $.02.

 

[douglassmt]

Another data point

I used 14V in mine, but when I was in Synergy Air's QB class several years ago, there was a participant from Texas who was building a -10. He was an electronics guru for his day job, and we was firm in his intent to build a 28V system. He was planning a G900 panel as well. I don't recall all his reasons, just remember thinking he could probably do it. I went with the 14V system because I can't count any higher

 

[SteinAir]

I used 14V in mine, but when I was in Synergy Air's QB class several years ago, there was a participant from Texas who was building a -10. He was an electronics guru for his day job, and we was firm in his intent to build a 28V system. He was planning a G900 panel as well. I don't recall all his reasons, just remember thinking he could probably do it. I went with the 14V system because I can't count any higher

With the G900 there are "some" good reasons for going with 28V, mainly because you automatically get the big 16W radio output (most G900 installs have the comms powered at 28V regardless of airframe voltage for that reason).

That said; other than twins, turboprops, retracts, or a few other instances there just really isn't a strong cause for going with 28V in most RV's. We've done a good amount of both, but I'd say that unless you have a G900, air conditioning, or a few other items just stick with the 14V and you'll be golden.

Just my 2 cents as usual.

Cheers,
Stein

 

[Jackm]

12/24 v or 28 v

14 v for us....I know different industry but we used to work on trucks with 24v system and the OEM designed systems never seemed standard and hard to find parts. As high torque starters, LED technology, ect arrive, I believe a 14v system can be designed lightweight and effective for our RV. Also we want to know our system intimately and use our repairman cert to diagnose and repair if a problem arises. Again 28v has advantages, just not for everyone.

BTW...This Bryan guy knows how to count....so good his 10 has counted 400 hrs of flight in 531 days. He also has diagnosed a odd electrical problem and assisted others with thiers...so dont let him off easy! Only issue Bryan has that is electrical related and he cant seem to sort out, is why his 650 is lagging behind the all new and improved 430W

 

[togaflyer]

With all the various systems that can be installed, I can see if you had a significant demand to power those systems, a 28v is the way to go. For me, and the type of system Im considering installing, a 14v system will work fine.