X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 24 May 2009 01:11:25 -0400 Message-ID: X-Original-Return-Path: Received: from imr-m07.mx.aol.com ([64.12.138.209] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3651753 for lml@lancaironline.net; Sat, 23 May 2009 16:48:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.209; envelope-from=Sky2high@aol.com Received: from imo-da03.mx.aol.com (imo-da03.mx.aol.com [205.188.169.201]) by imr-m07.mx.aol.com (v107.10) with ESMTP id RELAYIN1-24a1860dd1be; Sat, 23 May 2009 16:47:25 -0400 Received: from Sky2high@aol.com by imo-da03.mx.aol.com (mail_out_v40_r1.5.) id q.c39.54d7a25e (42805) for ; Sat, 23 May 2009 16:47:21 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Sat, 23 May 2009 16:47:21 EDT Subject: Re: [LML] Re: Gear Relays are not working X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1243111641" X-Mailer: AOL 9.1 sub 5006 X-Spam-Flag:NO X-AOL-IP: 205.188.169.201 -------------------------------1243111641 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Bryan, Sorry, I should have read your original message more carefully. You said: "Then we remembered that the relays were mounted to a fiberglass bulkhead and the case needed to be grounded so we attached a ground from the relay mounting base to ground bar. Tried the gear.....now it worked...BUT it instantly fried the ground wire on the relay small terimal......" This means I have no idea how this circuit was wired, but it was not as Lancair specified. The usual intermittent relay as provided by Lancair has 2 large terminals to transfer high amperage juice (motor power), an "S" terminal and an "I" terminal. "S" stands for Switched and was to be supplied with +12 VDC to the coil from the control circuit (thru selector switch and pressure switch - and squat switch on the up side if desired). The ground side of the relay coil is provided by the case. "I" stands for indicate and supplies +12 VDC to an Indicator light from the contactor itself when 12 volts is present across the large terminals. There should not have been a "ground" wire on either of the small terminals. If you grounded the "I" terminal, then you have demonstrated one oversight that Lancair made in their wiring diagram. When the contact was made, current flowed thru the contactor and the "I" terminal straight to ground. That ground wire was not rated for 50 or so amps, the level of the circuit breaker protected circuit that runs the motor (using #8 wire, not 18, 20 or 22 - just big enough to light an indicator bulb). If you understood this, you will see why some of us recommend that small diodes be used to disallow any feedback to the other relay "I" post (both diodes arrow head pointed to the indicator lamp) to allow itself burn up rather than start a wire fire should the indicator wire be shorted (as you found out). I actually have also added an inline fuse back at the relays for additional safety. Note that if the pump breaker is pulled and the up or down relay is selected, the indicator light will not come on since there is no power present at the contactor. This is the problem that can cause an intermittent relay to destroy itself through over heating because aircraft electric work was being done with the master switch on and the pump breaker pulled, but not the relay breaker and the "pump selected" indicator light is not on.. Some recommend no change, but instead of pulling the pump breaker, pull the relay breaker so no power relay can be selected, thus no power to the pump. Of course, some have also wired other miscellaneous thigamajigs (technical term of art) to that same breaker and so they don't want to pull it to just disable the pump. These folks are likely to ruin their intermittent use relays at some point. This results in the suggestion that the relays be inline fused or go thru a breaker after the pump breaker so that pulling the pump breaker removes all electricity from all pump related circuits. A continuous duty relay coil draws little power so that the contactor is relatively weakly pulled in and held for long times without over heating (i.e. master relay). An intermittent duty relay has a coil that draws more power, snappily closes the more heavily sprung contactor and holds it for short periods of time. This sort of coil will heat up if held too long. The firm make and break of such a relay is to reduce arcing and contact burning. But, perhaps your original relays were like the continuous duty master relay, a special case relay. This is where one of the large terminals is marked "BAT" and is directly connected to the + terminal of the battery. This relay is internally wired so that the BAT side is also connected to one side of the coil. Thus, the single small terminal need only be grounded to activate it. Of course, I couldn't explain why your wire burned if such a relay was used. Lancair was advised of these conditions many, many years ago. Their only change was to add the diodes to the Legacy pump wiring diagram. The rest is history as no two wiring diagram are alike if they exist at all. Scott Krueger In a message dated 5/23/2009 12:59:15 P.M. Central Daylight Time, vonjet@gmail.com writes: My gear system was wired using the Legacy Wiring diagram. By resistance I meant 0 ohms. The intermittant relays that were in the plane originally were the ones that lancair sells on their website. Now I have some continuous duty relays in their place. So my next question is: If the Lancair wiring diagrams are wrong and it seems that some of you out there have figured out a right way to do it, why haven't you sent it to Lancair for them to update their manuals or at least load it up on LML so all of us can get our aircraft wired properly? Maybe you can email me a copy? thanks Bryan On Fri, May 22, 2009 at 12:57 PM, <_vonjet@gmail.com_ (mailto:vonjet@gmail.com) > wrote: No squat switch. I built the plane and I did not put a squat switch in. On the good note I spent all day yesterday retracting and free falling the gear and it all works perfectly. Bryan Sent from my Verizon Wireless BlackBerry ____________________________________ From: _Sky2high@aol.com_ (mailto:Sky2high@aol.com) Date: Fri, 22 May 2009 15:44:32 -0400 To: <_lml@lancaironline.net_ (mailto:lml@lancaironline.net) > Subject: [LML] Re: Gear Relays are not working Bryan, While the plane is on jacks, one test would be to open the dump valve (relieve all pressure) and see if the pump runs in the gear down direction, but not in the up. This would suggest that there is some sort of "squat" switch. If so, the most frequently used one relies on pitot-static pressure so the gear cannot be retracted until 70 KIAS is exceeded. Some simply bypass the switch with a jumper when doing the gear checks while others may have installed a bypass switch, sometimes hidden behind the panel. Scott Krueger In a message dated 5/21/2009 5:24:34 A.M. Central Daylight Time, _vonjet@gmail.com_ (mailto:vonjet@gmail.com) writes: My lancair 360 was wired professionally. When we tried to do the gear retraction tests.....nothing. We checked all the wires and made sure all were getting power where they should. Checked the breakers, switch etc. We overran the relay and the motor ran so we figured it was a bad relay......went to Napa and bought 2 new relays today. Installed them. Same thing....nothing. Then we remembered that the relays were mounted to a fiberglass bulkhead and the case needed to be grounded so we attached a ground from the relay mounting base to ground bar. Tried the gear.....now it worked...BUT it instantly fried the ground wire on the relay small terimal......tried to measure the ohms of the relays and no resistance....how could it be that I have 4 dead relays all brand new? So today I installed a Master Relay. The ones that are all metal case. Now the gear works and no wires are getting fried........but Im not happy with this result as it makes no sense why the normal relays for this job aren't working....anybody have any ideas? Bryan ____________________________________ _Huge savings on HDTVs from Dell.com!_ (http://pr.atwola.com/promoclk/100126575x1221836042x1201399880/aol?redir=http://ad.doubleclick.net/clk;215073686 ;37034322;b) **************A strong credit score is 700 or above. See Yours in Just 2 Easy Steps! (http://pr.atwola.com/promoclk/100126575x1222585033x1201462753/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&b cd=Maystrongfooter52309NO115) -------------------------------1243111641 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Bryan,
 
Sorry, I should have read your original message more carefully. = You said:
 
"Then we remembered that the relays were mounted to a fiberglass bulk= head and the case needed to be grounded so we attached a ground from the relay= mounting base to ground bar. 
Tried the gear.....now it worked...BUT it instantly  fried the= ground wire on the relay small terimal......"
 
This means I have no idea how this circuit was wired, but it was not= as Lancair specified.  The usual intermittent relay as provided by Lanca= ir has 2 large terminals to transfer high amperage juice (motor power), an "S" te= rminal and an "I" terminal.  "S" stands for Switched and was to be supplied= with +12 VDC to the coil from the control circuit (thru selector switch and pre= ssure switch - and squat switch on the up side if desired).  The ground sid= e of the relay coil is provided by the case.  "I" stands for indicate and= supplies +12 VDC to an Indicator light from the contactor itself wh= en 12 volts is present across the large terminals. 
 
There should not have been a "ground" wire on either of the small terminals.  If you grounded the "I" terminal, then you have demonstra= ted one oversight that Lancair made in their wiring diagram.  When the co= ntact was made, current flowed thru the contactor and the "I" terminal straight= to ground.  That ground wire was not rated for 50 or so amps, the= level of the circuit breaker protected circuit that runs the motor (using #8 wir= e, not 18, 20 or 22 - just big enough to light an indicator bulb).
 
If you understood this, you will see why some of us recommend that small diodes be used to disallow any feedback to the other relay= "I" post (both diodes arrow head pointed to the indicator lamp) to allow= itself burn up rather than start a wire fire should the indicator wire be shorted= (as you found out).  I actually have also added an inline fuse back at th= e relays for additional safety.
 
Note that if the pump breaker is pulled and the up or down relay is= selected, the indicator light will not come on since there is no power pre= sent at the contactor.  This is the problem that can cause an intermittent= relay to destroy itself through over heating because aircraft electric work was= being done with the master switch on and the pump breaker pulled, but not the re= lay breaker and the "pump selected" indicator light is not on.. 
 
Some recommend no change, but instead of pulling the pump breaker, pu= ll the relay breaker so no power relay can be selected, thus no power to the pump.  Of course, some have also wired other miscellaneous thigamajig= s (technical term of art) to that same breaker and so they don't want to pul= l it to just disable the pump.  These folks are likely to ruin their intermittent use relays at some point.  This results in the suggestio= n that the relays be inline fused or go thru a breaker aft= er the pump breaker so that pulling the pump breaker removes all electricity= from all pump related circuits.
 
A continuous duty relay coil draws little power so that the contactor= is relatively weakly pulled in and held for long times without over heating= (i.e. master relay).  An intermittent duty relay has a coil that draws more= power, snappily closes the more heavily sprung contactor and holds it for short periods of time.  This sort of coil will heat= up if held too long.  The firm make and break of such a relay is to reduce= arcing and contact burning.
 
But, perhaps your original relays were like the continuous duty = master relay, a special case relay.  This is where one of the large terminal= s is marked "BAT" and is directly connected to the + terminal of the battery.&n= bsp; This relay is internally wired so that the BAT side is also connected to= one side of the coil.  Thus, the single small terminal need only be groun= ded to activate it.  Of course, I couldn't explain why your wire burned= if such a relay was used.
 
Lancair was advised of these conditions many, many years ago.&nb= sp; Their only change was to add the diodes to the Legacy pump wiring diagram.=
 
The rest is history as no two wiring diagram are alike if they exist= at all.
 
Scott Krueger
 
In a message dated 5/23/2009 12:59:15 P.M. Central Daylight Time, vonjet@gmail.com writes:
My gear system was wired using the Legacy Wiring diagram.  By resistance I= meant 0 ohms. The intermittant relays that were in the plane originally were= the ones that lancair sells on their website.
Now I have some continuous duty relays in their place. 

So my next question is:  If the Lancair wiring diagrams are wr= ong and it seems that some of you out there have figured out a right way to= do it, why haven't you sent it to Lancair for them to update their manuals or= at least load it up on LML so all of us can get our aircraft wired properly?
Maybe you can email me a copy?
thanks
Bryan

On Fri, May 22, 2009 at 12:57 PM, <vonjet@gmail.com> wrote:<= BR>
No= squat switch. I built the plane and I did not put a squat switch in. On the= good note I spent all day yesterday retracting and free falling the gear an= d it all works perfectly.
Bryan

Sent from my Verizon Wireless BlackBerry

From: Sky2high@aol.com
Date: Fri, 22 May 2009= 15:44:32 -0400
To: <lml@lancaironline.net>
Subject: [LML]= Re: Gear Relays are not working

Bryan,
 
While the plane is on jacks, one test would be to open the= dump valve (relieve all pressure) and see if the pump runs in the gear= down direction, but not in the up.  This would suggest that there is= some sort of "squat" switch.  If so, the most frequently used one= relies on pitot-static pressure so the gear cannot be retracted until= 70 KIAS is exceeded.  Some simply bypass the switch with a jumper wh= en doing the gear checks while others may have installed a bypass switch,= sometimes hidden behind the panel. 
 
Scott Krueger
 
In a message dated 5/21/2009 5:24:34 A.M. Central Daylight Time,= vonjet@gmail.com writes:
My lancair 360 was wired professionally. When we tried to do the gear= retraction tests.....nothing. We checked all the wires and made sure= all were getting power where they should. Checked the breakers, switch= etc. 
We overran the relay and the motor ran so we figured it was a= bad relay......went to Napa and bought 2 new relays today. Installed the= m. Same thing....nothing.  Then we remembered that the relays were= mounted to a fiberglass bulkhead and the case needed to be grounded= so we attached a ground from the relay mounting base to ground bar. <= /DIV>
Tried the gear.....now it worked...BUT it instantly  fried= the ground wire on the relay small terimal......tried to measure the ohm= s of the relays and no resistance....how could it be that I have 4 dead= relays all brand new?
So today I installed a Master Relay.  The ones that are al= l metal case. Now the gear works and no wires are getting fried.......= .but Im not happy with this result as it makes no sense why the normal re= lays for this job aren't working....anybody have any ideas?

Bryan


A strong credit= score is 700 or above. See= Yours in Just 2 Easy Steps!
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