X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-galgo.atl.sa.earthlink.net ([209.86.89.61] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6621294 for lml@lancaironline.net; Sun, 01 Dec 2013 15:31:17 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.61; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=R5YYf6ORQafe+Tf8J5s0sib3vAlFABP6+E50nagESehABnu1Ne5M+myeJRjqbg6Y; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [72.92.128.101] (helo=[192.168.1.24]) by elasmtp-galgo.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1VnDfA-0007e0-83 for lml@lancaironline.net; Sun, 01 Dec 2013 15:30:44 -0500 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: multipart/alternative; boundary=Apple-Mail-68--399249851 Subject: Re: [LML] Re: [LNC2] Oildyne Hydraulic Pump Inrush Date: Sun, 1 Dec 2013 15:30:43 -0500 In-Reply-To: To: "Lancair Mailing List" References: Message-Id: X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da9407d6d60987cd14a79a169526030daaf44350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 72.92.128.101 --Apple-Mail-68--399249851 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Chris, say again the vertical scale? 30A/division !=3D 50ma How much is a tick mark? On Dec 1, 2013, at 9:36 AM, Chris Zavatson wrote: FWIW, attached are some screen shots of the pump running a single = cylinder. The vertical scale is 30A / division or 50ma. And just for = kicks, the shot with two steady state levels is the pump running up = against the pressure relief valve. =20 Chris Zavatson N91CZ 360std http://www.n91cz.net/ On Thursday, November 28, 2013 6:24 PM, Colyn Case = wrote: good info. thanks! On Nov 28, 2013, at 4:56 PM, John Cooper wrote: Today I inserted a 75A / 50mV shunt in the power lead to my hydraulic = pump in order to measure the current draw. I connected my Fluke 87-V = digital voltmeter on the 600mV range across the sense terminals of the = shunt . With the pump running in the "gear down" direction and the = equalization valve open, the motor was drawing a steady 29 Amps. I then = shut off the pump, closed the equalization valve, and with the Fluke in = the "250 uS peak" mode, measured the inrush when the pump started up = again briefly. Would you believe 135 Amps! (Disclaimer: I purchased the = shunt on eBay and can't vouch for its calibration.) Next time the plane is up on jacks, I'll re-do this test in both gear up = and gear down directions. Also, I intend to temporarily remove the ZNRs = across the hydraulic relay contacts and measure the voltage spikes with = no protection. -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html --Apple-Mail-68--399249851 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii
FWIW, attached are some screen shots of = the pump running a single cylinder.  The vertical scale is 30A / = division or 50ma.  And just for kicks, the shot with two steady = state levels is the pump running up against the pressure relief = valve.
 
Chris = Zavatson
N91CZ
360std=


=
On Thursday, November = 28, 2013 6:24 PM, Colyn Case <colyncase@earthlink.net> = wrote:
good = info.  thanks!

On Nov 28, 2013, at 4:56 PM, John Cooper = wrote:

Today I inserted a 75A / 50mV shunt in the power lead to = my hydraulic pump in order to measure the current draw. I connected my = Fluke 87-V digital voltmeter on the 600mV range across the sense = terminals of the shunt . With the pump running in the "gear down" = direction and the equalization valve open, the motor was drawing a = steady 29 Amps. I then shut off the pump, closed the equalization valve, = and with the Fluke in the "250 uS peak" mode, measured the inrush when = the pump started up again briefly. Would you believe 135 Amps!  = (Disclaimer: I purchased the shunt on eBay and can't vouch for its = calibration.)

Next time the plane is up on jacks, I'll re-do this = test in both gear up and gear down directions. Also, I intend to = temporarily remove the ZNRs across the hydraulic relay contacts and measure the voltage spikes with no = protection.


--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html=


--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html=

=
<SDS00002.BMP><SDS00003.BMP><SDS00004.BMP>--
For archives and unsub http://mail.= lancaironline.net:81/lists/lml/List.html

= --Apple-Mail-68--399249851--