Hi Valin,
Can you post some pictures showing how that AC went in? I
would like to see if I could get something like that going for my 320. I
really like the idea of taking it out when not needed.
Thank you,
Craig
Lancair N73S
From: Valin & Allyson
Thorn [mailto:thorn@starflight.aero]
Sent: Monday, May 11, 2009 5:24 PM
To: lml@lancaironline.net
Subject: 28VDC Ground Power Supply Options
Thank you all for your helpful advice on and off the list.
The LML people are a great resource.
Our Legacy is still under construction. We want to be able to
do system testing before the engine is installed and without the engine running
after it is. Our desire for a power supply sized around 50A is because
we’re about to begin testing of an all electric air conditioning system
we’re developing for the Legacy in partnership with an aircraft A/C
company. The whole system sits behind the seats, there is no P-51 air
scoop, and we get the cold air in front of the pilots. Oh, and for the
winter or if you want to off-load 40 lbs, it can be removed in less than 5
minutes. Anyway, I digress…J The A/C system running at steady
state pulls about 30A between the compressor, condenser fan, and evaporator
blower.
We’d also like to eventually do simple EMI testing.
With all the avionics on we’ll cycle other components like gear, lights,
and A/C looking for interference. We’re planning on a Garmin G900X
integrated avionics system and it pulls about 15A max intermittent (for 28V
system).
The cheapest approach is a good size battery with a serious charger
to get power for brief periods of time. We want to do some long duration
testing so we’ve decided to get a StartPac Portable Power Supply Model
53050 which can provide 50A continuously at 28.5 VDC, with over voltage and
over current protection. ACS price is $896.
We’re planning to add two Odyssey batteries to the set up to
provide more surge capacity and ensure good power quality. We’re
assuming we can work a setup where the StartPac power supply just looks like
the power coming from the alternator and the batteries (2 Odyssey 12V in
series) with a voltage regulator in there somewhere… We still have
some homework to do and welcome more advice from the DC power distribution
gurus out there on the best way to set this up.
Thanks,
Valin
Legacy in work
Hot & Humid Houston, Texas
http://www.starflight.aero/legacy
From: Valin & Allyson
Thorn [mailto:thorn@starflight.aero]
Sent: Wednesday, May 06, 2009 6:52 PM
To: Lancair Mail List (lml@lancaironline.net)
Subject: 28VDC Ground Power Supply Options
Hello LML gang,
Could I get some advice on the best way to get a 28 VDC 50 Amp
power supply set up in our hangar? On the web I’ve seen $5000
ground power units that can be plugged into our hangar’s AC power outlets
to solve the problem… Surely there’s a cheaper way to do
this. Anyone know of a more affordable source? Maybe a couple of
12V car batteries ganged together with a battery charger in there
somewhere.
Suggestions?
Thanks,
Valin Thorn
Legacy
Texas
http://www.starflight.aero/legacy