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1. 04:33 AM - Sv: ULPower Alternator/Regulator (Yahoo Mail)
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| Subject: | ULPower Alternator/Regulator |
Hi!
Here is what ULPower says about their regulators capacity to handle failure
s. The capacitor is key....
This is from the 520T manual available on net. The 30 Amp installation migh
t be different, but is also available online.
"The ECU needs a stable DC output . If the battery fails, or there is an op
en contact inside, the buffering characteristics from the battery fail also
. Such a situation may result in an unstable power supply to the ECU. Ther
efore, we strongly recommend the installation of a genuine ULP capacitor (t
his capacitor is able to cover for the big amount of amps coming from the a
lternator/regulator) parallel on the battery.
Likewise, a failure of the RR may result in an erratic power output, which
is buffered by the battery and capacitor."
Best regards
Gjermund Westad
________________________________
Fra: owner-aeroelectric-list-server@matronics.com <owner-aeroelectric-list-
server@matronics.com> p=E5 vegne av Sebastien <cluros@gmail.com>
Sendt: l=F8rdag 25. desember 2021 05:23
Til: aeroelectric-l. <aeroelectric-list@matronics.com>
Emne: Re: AeroElectric-List: ULPower Alternator/Regulator
As Dan already posted, the alternator is permanent magnet.
I was wondering more if anyone knows if the voltage regulator has any over-
voltage protection included. ULPower are apparently very good about respond
ing to inquiries so I will send them an email and post the reply to this li
st.
In any case, the electrical system on the aircraft in question has already
been installed but was designed by a highly qualified and experienced elect
rical & robotics engineer with no GA aircraft knowledge. The aircraft owner
sent me the diagram so that I could admire it but a quick and dirty FMEA s
howed some problems. A review of the manufacturer's instructions lead me to
suggest that they rewire it to conform with those instructions but since t
he alternator wiring already includes a current limiter and a solenoid I th
ought it would be appropriate to leave those in rather than create the prob
lem Joe pointed out vis a vis shorted b lead.1 If I can get permission I wi
ll post the schematic to the list; notwithstanding its problematic features
it's quite a work of art.
Regards,
Sebastien
On Thu, Dec 23, 2021 at 2:11 PM Robert L. Nuckolls, III <nuckolls.bob@aeroe
lectric.com<mailto:nuckolls.bob@aeroelectric.com>> wrote:
At 11:16 AM 12/23/2021, you wrote:
Does anyone have experience with this system? My friend is installing a
UL350 Engine and their wiring diagram and instructions specify no protectiv
e
devices between the alternator and the battery.
Protecting b-lead wiring from hard faults within
the alternator itself is a legacy protocol in
T/C aircraft since the first Ford alternator was
bolted to a Cessna (approx 1964).
However, LOTS of automotive applications tie
the alternator b-lead right to battery (+)
(like my '87 GMC) with some later models
adding a fusible link at the battery end
(like the 97 Chevy I worked on last week).
What kind of alternator is on the UL350, wound
field or permanent magnet?
Does anyone know if this alternator/regulator combination
can suffer from an overvoltage event? Or is the regulator
fault tolerant?
There is NO alternator system immune to OV events.
Probability, severity and risk run the gamut from
a little puff of smoke to a major incendiary event.
That needs to be sorted out in a failure mode
effects analysis with appropriate prophylactics
incorporated.
As supplier of the system, the engine manufacturer
SHOULD have conducted those studies and published
well considered protocols in their manual . . .
unfortunately, few engine suppliers have any notion
of what that process entails.
The usual answer to a query on the matter is: "we've
got xxxx of these flying with no reported events of
noteworthy magnitude."
For this List to offer any more considered advice,
much more data are needed as to system characteristics.
The SAFE thing is to incorporate b-lead and ov protection
as a matter of policy . . . it's light, cheap and better
to have it and not need it as opposed to needing and
not having.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
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