X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 09 Feb 2011 11:03:32 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124] verified) by logan.com (CommuniGate Pro SMTP 5.4c2a) with ESMTP id 4843633 for lml@lancaironline.net; Wed, 09 Feb 2011 10:17:41 -0500 Received-SPF: none receiver=logan.com; client-ip=71.74.56.124; envelope-from=Wolfgang@MiCom.net X-Original-Return-Path: X-Authority-Analysis: v=1.1 cv=+c36koQ5Dcj/1qolKHjtkYAGXvrVJRRiKMp+84F5sLg= c=1 sm=0 a=0wjGnQQ0WXcA:10 a=MHZY6FYWMEQOp7S43i2QIw==:17 a=Ia-xEzejAAAA:8 a=CjxXgO3LAAAA:8 a=MwWsI94oAAAA:8 a=3oc9M9_CAAAA:8 a=H8vYBql7AAAA:8 a=pg7aS07O-_0jb1S-4i0A:9 a=HyhCik18FpQsMcyQ-EsA:7 a=EtqSKgq-Q3FZ25SeNE0jkJKzdSQA:4 a=wPNLvfGTeEIA:10 a=EzXvWhQp4_cA:10 a=rC2wZJ5BpNYA:10 a=-Zujgq040EwA:10 a=U8Ie8EnqySEA:10 a=OHqb0wQA6tnuUqOO:21 a=zsMR-FkqC7B3XPEV:21 a=JXZm4Vx1lf1CfYB4o4gA:9 a=MVNaCmGLP5QSxAKAF5cA:7 a=opnnTvoMZ_mlFr6nlBxwpx5S0DcA:4 a=gb0WqhqYqBmL_sMM:21 a=QMB90FYH1lOsSxIc:21 a=MHZY6FYWMEQOp7S43i2QIw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.218.201.50 Received: from [74.218.201.50] ([74.218.201.50:1231] helo=Lobo) by hrndva-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 21/A5-24070-3FFA25D4; Wed, 09 Feb 2011 15:17:07 +0000 X-Original-Message-ID: <008f01cbc86c$67ea42a0$6401a8c0@Lobo> From: "Wolfgang" X-Original-To: References: Subject: Re: LNC2 Hydraulic Landing Gear Pressure Switch Wear Issues X-Original-Date: Wed, 9 Feb 2011 10:17:03 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008C_01CBC842.7EF08600" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_008C_01CBC842.7EF08600 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 500ma contact rating for a pressure switch will never work on a solenoid = operated hydraulic pump. As Bill just indicated, 4 amps to the solenoid that runs the pump is = typical. The only way that 500ma pressure switch can work is to use a relay in = between the switch and the solenoid. . . . . or just use a relay on the original (new) pressure switch and = it's contacts will last a lot longer without the radio noise problem. Wolfgang ----- Original Message -----=20 From: Bill Hannahan=20 To: lml@lancaironline.net=20 Sent: Tuesday, February 08, 2011 2:58 PM Subject: LNC2 Hydraulic Landing Gear Pressure Switch Wear Issues Great idea, but my relay coils (vintage 1990 360) require 4 = amps, tested today, perhaps 5 amps with engine running. We would need a = power transistor to supply the required current. Anybody know of a similar PS with a 5A or greater rating? Regards, Bill Hannahan wfhannahan@yahoo.com --- On Mon, 2/7/11, Bruce wrote: From: Bruce Subject: [LML] Re: LNC2 Hydraulic Landing Gear Pressure Switch = Wear Issues To: lml@lancaironline.net Date: Monday, February 7, 2011, 8:18 PM I would think that =BD amp at 14v should be enough. Bruce WWW.Glasair.org=20 -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On = Behalf Of Sky2high@aol.com Sent: Monday, February 07, 2011 2:53 PM To: lml@lancaironline.net Subject: [LML] Re: LNC2 Hydraulic Landing Gear Pressure Switch = Wear Issues Their specs look great. Is the 500 mA current limitation = adequate for operating clunky 12 VDC intermittent relays (the pump power = switch relays)? Grayhawk In a message dated 2/7/2011 11:32:18 A.M. Central Standard = Time, BGray@glasair.org writes: Several of our guys (including me) have junked our = mechanical pressure switches and moved to solid state adjustable = switches. = http://www.automationdirect.com/adc/Search/Search?searchquery=3DPSD25-OP-= 5800H&cmd=3DSearch&fctype=3Dadc.falcon.search.SearchFormCtrl&TxnNumber=3D= -1 Bruce WWW.Glasair.org=20 -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net] On = Behalf Of Don Gordon Sent: Monday, February 07, 2011 7:45 AM To: lml@lancaironline.net Subject: [LML] LNC2 Hydraulic Landing Gear Pressure Switch = Wear Issues I have recently replaced both my high pressure and low = pressure switches in the hydraulic system for the landing gear. These = switches began to have trouble providing a positive and discrete on/off = event when the hydraulic pressure reached the prescribed limits. I = began to hear strange crackling and static noises in my headset just = prior to the hydraulic pump running (though it would just run for a = fraction of a second to re-pressurize). These strange sounds in my = headset began to occur longer and longer prior to the pump tripping on. = I also began to notice some other odd electrical issues with the = aircraft. Finally, I began to suspect these switches were faulty are = replaced both of them. The problem went away and so did my electrical = issues I experienced. =20 ------=_NextPart_000_008C_01CBC842.7EF08600 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
500ma contact rating for a pressure = switch will=20 never work on a solenoid operated hydraulic pump.
As Bill just indicated, 4 amps to the = solenoid that=20 runs the pump is typical.
 
The only way that 500ma pressure switch = can work is=20 to use a relay in between the switch and the solenoid.
 
. . . . or just use a relay on the = original (new)=20 pressure switch and it's contacts will last a lot longer without the = radio noise=20 problem.
 
Wolfgang
 
----- Original Message -----
From:=20 Bill=20 Hannahan
Sent: Tuesday, February 08, = 2011 2:58=20 PM
Subject: LNC2 Hydraulic Landing = Gear=20 Pressure Switch Wear Issues

Great idea, but my relay coils (vintage 1990 360) = require=20 4 amps, tested today, perhaps 5 amps with engine running. We = would need=20 a power transistor to supply the required = current.

Anybody know=20 of a similar PS with a 5A or greater rating?

Regards,
Bill Hannahan


--- On = Mon,=20 2/7/11, Bruce <BGray@glasair.org>=20 wrote:

From:=20 Bruce <BGray@glasair.org>
Subject: [LML] Re: LNC2 = Hydraulic=20 Landing Gear Pressure Switch Wear Issues
To:=20 lml@lancaironline.net
Date: Monday, February 7, 2011, 8:18=20 PM

I = would think=20 that =BD amp at 14v should be enough.

 

Bruce
WWW.Glasair.org=20

-----Original=20 Message-----
From:=20 Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of=20 Sky2high@aol.com
Sent: Monday, February = 07, 2011=20 2:53 PM
To: = lml@lancaironline.net
Subject: [LML] Re: LNC2 = Hydraulic=20 Landing Gear Pressure Switch Wear Issues

 

Their specs=20 look great.  Is the 500 mA current limitation adequate = for=20 operating clunky 12 VDC intermittent relays (the pump = power=20 switch relays)?

 

Grayhawk

 

In = a message=20 dated 2/7/2011 11:32:18 A.M. Central Standard Time, = BGray@glasair.org=20 writes:

Several of=20 our guys (including me) have junked our mechanical pressure = switches=20 and moved to solid state adjustable = switches.

 

http://www.automationdirect.com/adc/Search/Search?searchq= uery=3DPSD25-OP-5800H&cmd=3DSearch&fctype=3Dadc.falcon.search.Sea= rchFormCtrl&TxnNumber=3D-1

 

 

Bruce
WWW.Glasair.org=20

-----Original=20 Message-----
From:=20 Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Don=20 Gordon
Sent:=20 Monday, February 07, 2011 7:45 AM
To:=20 lml@lancaironline.net
Subject: [LML] LNC2 = Hydraulic=20 Landing Gear Pressure Switch Wear Issues

 

I have=20 recently replaced both my high pressure and low pressure = switches in=20 the hydraulic system for the landing gear.  These = switches=20 began to have trouble providing a positive and discrete = on/off event=20 when the hydraulic pressure reached the prescribed = limits.  I=20 began to hear strange crackling and static noises in my = headset just=20 prior to the hydraulic pump running (though it would just = run for a=20 fraction of a second to re-pressurize).  These strange = sounds=20 in my headset began to occur longer and longer prior to the = pump=20 tripping on.  I also began to notice some other odd = electrical=20 issues with the aircraft.  Finally, I began to suspect = these=20 switches were faulty are replaced both of them.  The = problem=20 went away and so did my electrical issues I=20 experienced.

 

 


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