Return-Path: Sender: (Marvin Kaye) To: lml Date: Sat, 05 Jul 2003 10:20:39 -0400 Message-ID: X-Original-Return-Path: Received: from mta4.rcsntx.swbell.net ([151.164.30.28] verified) by logan.com (CommuniGate Pro SMTP 4.1b8) with ESMTP id 2456786 for lml@lancaironline.net; Sat, 05 Jul 2003 10:10:10 -0400 Received: from john (adsl-66-141-252-52.dsl.kscymo.swbell.net [66.141.252.52]) by mta4.rcsntx.swbell.net (8.12.9/8.12.3) with SMTP id h65EA9wI016351 for ; Sat, 5 Jul 2003 09:10:09 -0500 (CDT) X-Original-Message-ID: <000601c342ff$14e8ca40$6401a8c0@john> From: "Lee Metcalfe" X-Original-To: Subject: [LML] Re: Electrical Power Budget X-Original-Date: Sat, 5 Jul 2003 09:09:42 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01C342D5.2BA4E540" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0003_01C342D5.2BA4E540 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Rob: I haven't calculated the electrical load in my airplane, but I can tell = you from practical experience that the following load overwhelms my = 40-amp alternator: battery contactor avionics fan turn coordinator intercom nav/comm (KX-155) gps (KLN-94) xponder (KT-76) EDM-700 (engine monitor) aux pump instrument panel lighting (minimal) nav lights landing lights (two 55-watt halogens) Whelen strobes and either gear or flap actuation This would be the normal configuration for a night landing, which is = when I noticed the "BATT" warning on the EDM-700 as I lowered the gear = on downwind. I got it again each time I added a notch of flaps. The = "BATT" warning is activated when bus voltage drops below 12v. Since = it's the gear or flap actuation that puts it over the edge, and these = are obviously intermittent loads, I haven't worried too much about it. = Next alternator change I will consider moving up in amperage. My alternator is an automotive type (Mitsumi, I think). It only has = about 15 hours on it, as its predecessor burned out after about 470 = hours. Just some real world experience, for what it's worth. Lee "Moondog" Metcalfe N320WH - LNC2 - IO-320-D1C - 485 hrs. - Kansas City (IXD) ------=_NextPart_000_0003_01C342D5.2BA4E540 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Rob:

I haven't calculated the electrical = load in my=20 airplane, but I can tell you from practical experience that the = following=20 load overwhelms my 40-amp alternator:

battery contactor

avionics fan

turn coordinator

intercom

nav/comm (KX-155)

gps (KLN-94)

xponder (KT-76)

EDM-700 (engine monitor)

aux pump

instrument panel lighting = (minimal)

nav lights

landing lights (two 55-watt = halogens)

Whelen strobes

and either gear or flap = actuation

This would be the normal configuration = for a night=20 landing, which is when I noticed the "BATT" warning on the EDM-700 as I = lowered=20 the gear on downwind. I got it again each time I added a notch of=20 flaps. The "BATT" warning is activated when bus voltage drops = below=20 12v. Since it's the gear or flap actuation that puts it over the = edge, and=20 these are obviously intermittent loads, I haven't worried too much = about=20 it. Next alternator change I will consider moving up in=20 amperage.

My alternator is an automotive type = (Mitsumi, I=20 think). It only has about 15 hours on it, as its predecessor = burned out=20 after about 470 hours.

Just some real world experience, for = what it's=20 worth.

Lee "Moondog" Metcalfe

N320WH - LNC2 - IO-320-D1C - 485 hrs. - = Kansas City=20 (IXD)

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