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Stall Warner - switch problems

 
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clivesutton



Joined: 23 Jan 2013
Posts: 105
Location: KENILWORTH

PostPosted: Fri Jun 16, 2017 1:17 pm    Post subject: Stall Warner - switch problems Reply with quote

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S


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jonathanmilbank



Joined: 14 Apr 2012
Posts: 200
Location: aberdeen

PostPosted: Sat Jun 17, 2017 12:31 am    Post subject: Re: Stall Warner - switch problems Reply with quote

Hi Clive,

My stall warner switch has worked reliably for about 15 years, so my memory of an initial problem is vague. But your "it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed" rings a bell in my head.

I'm my case it was caused, as far as I can remember, by the air pressure tube/s being fitted to the wrong spigot/s. Simply swapping the tube/s around cured it.

The adjustment screw in the middle needed little or no turning to get the warner to activate at 5 knots above stall.

Jonathan


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PostPosted: Sat Jun 17, 2017 3:46 am    Post subject: Stall Warner - switch problems Reply with quote

I fixed it by fitting a Smartass, easily heard via headset & impossible to ignore, neither of which can be said for stall warner even when working - which sounds as a very distant minor squeak using modern headsets!
Regards, Davi (Joyce, GXSDJ)


On 2017-06-16 22:17, clivesutton wrote:
Quote:
Quote:
--> Europa-List message posted by: "clivesutton" <clive.maf(at)googlemail.com (clive.maf(at)googlemail.com)>

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S


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budyerly(at)msn.com
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PostPosted: Sun Jun 18, 2017 7:46 pm    Post subject: Stall Warner - switch problems Reply with quote

Clive,
I haven’t had much of a problem with the stall warner switch itself, but now days, I put the switch in the wing and run wires to the panel and place the light near the airspeed indicator and the buzzer, if wanted, on the underside of the panel top so it will resonate. The switch is adjustable from the aileron belcrank access door with a Phillips head.

I had problems in some installations running a long tube from the wing to the cockpit as the Europa Mod installation states, and getting the accuracy I expected even with tight connections. I moved the sensor to the wing and it was fine. Go figure. The tubing is quite firm and doesn’t expand so I couldn’t figure it out and it wasn’t worth the time.

At 7.5 mbar or 3 inches of water(about 45 Knots IAS) pressure it is pretty easy to check on the ground. Check your wiring first. Bypass the switch and check the light/buzzer. Push 3 inches of water pressure to the inlet tube and or the sensor in the fuselage (using a manometer) and check the switch operation. If it checks on the ground it should work in the air. Your Ops check for your periodic inspections is: Light should be on when stopped, stay on until about 50-55 on takeoff. Come on about 3 Gs at Vman or maneuvering speed or 5-10 knots above the straight ahead stall of course... Since the wing stalls near 17 degrees, and the inlet tube is pretty close to that, you should be getting full pressure in the tube and if the switch ground checks, it all should work.

RS 317-443 and Herga 6753 are identical switches.  Honeywell has switches but are not adjustable so are worthless.
China has a manufacturer:   Antunes controls. Their SMD series is in the range.   Big and heavy and is plus or minus .5 inches water, so not terribly accurate.
8021203090
0.17" to 6" W.C.
Yes


I find that it is important to check all pressure and temp sensors for accuracy. Sensors are not always out of the box accurate. Test it and be in the know for sure. If it works on the bench, try installing the sensor closer in the wing near the spar connection. That’s why we call it experimental, we get just enough info to learn what really works for us.

Of course you can spend much more money and time and research AOA systems and put one of those in.

To be honest, I prefer the stall strips. Nice rumble just prior to the stall. See POH chapter 9. No bells or whistles. A straight wing plane needs little more normally. But electronics are nice….Sort of…

Regards,
Bud Yerly


Sent from Mail for Windows 10

From: clivesutton (clive.maf(at)googlemail.com)
Sent: Friday, June 16, 2017 5:23 PM
To: europa-list(at)matronics.com (europa-list(at)matronics.com)
Subject: Stall Warner - switch problems


--> Europa-List message posted by: "clivesutton" <clive.maf(at)googlemail.com>

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S




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PostPosted: Sun Jun 18, 2017 10:35 pm    Post subject: Stall Warner - switch problems Reply with quote

The SmartAss is not  Stall Warning System and just like Clive I have been struggling to get the the pressure switch to work correctly in the only UK flying Europa Motor Glider. This has been going on for ages stopping the motor Glider getting a Permit to Fly. I have a SmartAss fitted and it is not acceptable to the LAA as a stall warning system. None of the other motor gliders or gliders I fly have stall warning systems fitted we fly near the stall most of the time while using thermals and something bleating in your ear all the time is the last thing you want. However trying to get the LAA to except this point seems impossible, especially galling as the stall is such a non event in the Europa Motor Glider.

Regards
Ian Cook
G-CBHI
Sent from my iPhone

On 17 Jun 2017, at 12:49, "davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)> wrote:


Quote:

I fixed it by fitting a Smartass, easily heard via headset & impossible to ignore, neither of which can be said for stall warner even when working - which sounds as a very distant minor squeak using modern  headsets! 
Regards, Davi (Joyce, GXSDJ)
   

On 2017-06-16 22:17, clivesutton wrote:
Quote:
Quote:
--> Europa-List message posted by: "clivesutton" <clive.maf(at)googlemail.com (clive.maf(at)googlemail.com)>

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S


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PostPosted: Mon Jun 19, 2017 4:31 am    Post subject: Stall Warner - switch problems Reply with quote

Absolutely but you can get the plane approved with stall strips. David


On 2017-06-18 13:58, Ian Cook wrote:
Quote:
The SmartAss is not Stall Warning System and just like Clive I have been struggling to get the the pressure switch to work correctly in the only UK flying Europa Motor Glider. This has been going on for ages stopping the motor Glider getting a Permit to Fly. I have a SmartAss fitted and it is not acceptable to the LAA as a stall warning system. None of the other motor gliders or gliders I fly have stall warning systems fitted we fly near the stall most of the time while using thermals and something bleating in your ear all the time is the last thing you want. However trying to get the LAA to except this point seems impossible, especially galling as the stall is such a non event in the Europa Motor Glider. Regards
Ian Cook
G-CBHI Sent from my iPhone
On 17 Jun 2017, at 12:49, "davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)> wrote:
Quote:

I fixed it by fitting a Smartass, easily heard via headset & impossible to ignore, neither of which can be said for stall warner even when working - which sounds as a very distant minor squeak using modern headsets!
Regards, Davi (Joyce, GXSDJ)


On 2017-06-16 22:17, clivesutton wrote:
Quote:
Quote:
--> Europa-List message posted by: "clivesutton" <clive.maf(at)googlemail.com (clive.maf(at)googlemail.com)>

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S


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PostPosted: Mon Jun 19, 2017 10:32 am    Post subject: Stall Warner - switch problems Reply with quote

You do not fit stall strips on gliders especially ones with lamina flow wings. I am spending time cleaning the wings up by removing Outriggers sealing controls etc.


Regards


Ian 

Sent from my iPhone

On 19 Jun 2017, at 13:36, "davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)> wrote:


Quote:

Absolutely but you can get the plane approved with stall strips. David
   

On 2017-06-18 13:58, Ian Cook wrote:
Quote:
The SmartAss is not  Stall Warning System and just like Clive I have been struggling to get the the pressure switch to work correctly in the only UK flying Europa Motor Glider. This has been going on for ages stopping the motor Glider getting a Permit to Fly. I have a SmartAss fitted and it is not acceptable to the LAA as a stall warning system. None of the other motor gliders or gliders I fly have stall warning systems fitted we fly near the stall most of the time while using thermals and something bleating in your ear all the time is the last thing you want. However trying to get the LAA to except this point seems impossible, especially galling as the stall is such a non event in the Europa Motor Glider.

Regards
Ian Cook
G-CBHI
Sent from my iPhone

On 17 Jun 2017, at 12:49, "davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)" <davidjoyce(at)doctors.org.uk (davidjoyce(at)doctors.org.uk)> wrote:


Quote:

I fixed it by fitting a Smartass, easily heard via headset & impossible to ignore, neither of which can be said for stall warner even when working - which sounds as a very distant minor squeak using modern  headsets! 
Regards, Davi (Joyce, GXSDJ)
   

On 2017-06-16 22:17, clivesutton wrote:
Quote:
Quote:
--> Europa-List message posted by: "clivesutton" <clive.maf(at)googlemail.com (clive.maf(at)googlemail.com)>

I have the 0.072 PSI/5mBar/500Pascal Vacuum stall warner switch supplied by Europa fitted in G-YETI (RS Components part No 317-443) but I'm struggling to get it to work correctly - despite changing the switch for a new one today.

The first switch would not reliably make contact at the stall warn speed (light/intermittent squeaks at varying speeds) and whilst the other does work more reliably it is closed/the horn sounds once the a/c is back on the ground/at zero to low forward speed.

Has anyone else had this problem and can share how they fixed it or can anyone recommend another more reliable switch (based on personal experience in use) please? The pipe between switch and the hole just below the wing leading edge is correctly connected to the NO port A btw.

All inputs appreciated

Clive S


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clivesutton



Joined: 23 Jan 2013
Posts: 105
Location: KENILWORTH

PostPosted: Mon Jun 19, 2017 11:42 pm    Post subject: Re: Stall Warner - switch problems Reply with quote

Thanks to all for your contributions

As Bud has illuminated on, at 3" of water, the operating pressure is very low so the adjustment is very fiddly/has a very small range between success and on all the time. I have repositioned the switch taking care to 1) try and orientate it so that the adjustment screw points upwards and 2) to avoid stressing the plastic body of the switch. At optimum adjustment even a small side load on the spigot that the vacuum tube connects to (port A) will operate the switch at zero speed. Andy also advised me to make sure the orifice in the wing is drilled out to 4mm OD and 6mm deep. With all the above now implemented it now seems to work correctly, though it does stay on down to about 15kts on the ground.

The search for alternative adjustable switches has proved to be fruitless so far

Thanks again

Clive.

PS: Permit flight today!


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Kelvin Weston



Joined: 14 Apr 2010
Posts: 53
Location: Hampshire, UK

PostPosted: Tue Jun 20, 2017 12:59 pm    Post subject: Re: Stall Warner - switch problems Reply with quote

Hi Bud and all

Now I am really confused. I have fitted the Europa stall warning mod and switch but not yet used in anger.

How is this switch designed to work?

Is it normally closed and held open by pressure above a certain speed.
Or is it normally open and is closed by low pressure (vacuum), like a conventional Cessna stall warner, caused by the angle of the wing.

The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option.
The switch has a hose connection to both sides of what I assume is a diaphragm, so it is easy to connect incorrectly.

If it is normally closed then does that result in the buzzer operating continually on the ground until above the stall speed?
I think that would eventually get to be a bit of a pain, especially during long holds on the ground.


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PostPosted: Tue Jun 20, 2017 9:44 pm    Post subject: Stall Warner - switch problems Reply with quote

It's normally open, and activated when sufficient vacuum is applied.
Regards
Roddy kesterton g-ikrk

Sent from my iPhone

Quote:
On 20 Jun 2017, at 21:59, Kelvin Weston <kelv(at)kdweston.biz> wrote:



Hi Bud and all

Now I am really confused. I have fitted the Europa stall warning mod and switch but not yet used in anger.

How is this switch designed to work?

Is it normally closed and held open by pressure above a certain speed.
Or is it normally open and is closed by low pressure (vacuum), like a conventional Cessna stall warner, caused by the angle of the wing.

The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option.
The switch has a hose connection to both sides of what I assume is a diaphragm, so it is easy to connect incorrectly.

If it is normally closed then does that result in the buzzer operating continually on the ground until above the stall speed?
I think that would eventually get to be a bit of a pain, especially during long holds on the ground.

--------
Regards

Kelv Weston
Kit 497
kelv(at)kdweston.biz




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PostPosted: Fri Jun 23, 2017 1:01 pm    Post subject: Stall Warner - switch problems Reply with quote

Kelv,
If you go onto the Radio Spares web page and search. Pt No. 317-443 there is a full tech description.

Regards

Ian Cook

Sent from my iPad

Quote:
On 20 Jun 2017, at 22:03, Kelvin Weston <kelv(at)kdweston.biz> wrote:



Hi Bud and all

Now I am really confused. I have fitted the Europa stall warning mod and switch but not yet used in anger.

How is this switch designed to work?

Is it normally closed and held open by pressure above a certain speed.
Or is it normally open and is closed by low pressure (vacuum), like a conventional Cessna stall warner, caused by the angle of the wing.

The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option.
The switch has a hose connection to both sides of what I assume is a diaphragm, so it is easy to connect incorrectly.

If it is normally closed then does that result in the buzzer operating continually on the ground until above the stall speed?
I think that would eventually get to be a bit of a pain, especially during long holds on the ground.


Regards

Kelv Weston
Kit 497
kelv(at)kdweston.biz




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http://forums.matronics.com/viewtopic.php?p=470288#470288











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Kelvin Weston



Joined: 14 Apr 2010
Posts: 53
Location: Hampshire, UK

PostPosted: Sat Jun 24, 2017 11:53 am    Post subject: Re: Stall Warner - switch problems Reply with quote

Thanks Roddy and Ian

So, normally open contacts, closed / operated by the vacuum caused by the wing angle and therefore light and buzzer should be off on the ground.

Makes sense.

Does anybody with this mod fitted test it on the ground and if so, how?
A quick suck on the orifice like the Cessna.


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kelv@kdweston.biz
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PostPosted: Wed Jun 28, 2017 6:23 pm    Post subject: Stall Warner - switch problems Reply with quote

Kelvin,
The switch is a pressure switch. With the relative wind nearly straight on the air into the tube is under suction. The switch is assembled to the hose to the leading edge using its pressure side. The switch is normally open so with suction on the tube, the light is off at low angles.

At about 14 degrees angle of attack the switch is now under pressure from the ram air. The switch is normally open and at about 3 inches of water ish, the switch will close and allow current to flow to the light/horn.

Once you land, and the speed diminishes, the pressure drops and the switch opens and the horn goes off.

Not rocket science.

See photo below:
Regards,
Bud Yerly[img]cid:image001.png(at)01D2F05D.21C06F50[/img]

Sent from Mail for Windows 10

From: Kelvin Weston (kelv(at)kdweston.biz)
Sent: Tuesday, June 20, 2017 5:03 PM
To: europa-list(at)matronics.com (europa-list(at)matronics.com)
Subject: Re: Stall Warner - switch problems


--> Europa-List message posted by: "Kelvin Weston" <kelv(at)kdweston.biz>

Hi Bud and all

Now I am really confused. I have fitted the Europa stall warning mod and switch but not yet used in anger.

How is this switch designed to work?

Is it normally closed and held open by pressure above a certain speed.
Or is it normally open and is closed by low pressure (vacuum), like a conventional Cessna stall warner, caused by the angle of the wing.

The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option.
The switch has a hose connection to both sides of what I assume is a diaphragm, so it is easy to connect incorrectly.

If it is normally closed then does that result in the buzzer operating continually on the ground until above the stall speed?
I think that would eventually get to be a bit of a pain, especially during long holds on the ground.

--------
Regards

Kelv Weston
Kit 497
kelv(at)kdweston.biz




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PostPosted: Thu Jun 29, 2017 1:40 am    Post subject: Stall Warner - switch problems Reply with quote

Bud,
  Not very often I disagree with you, but the stall warning switch does not work as you describe. Under normal flight the switch senses +VE pressure (connecting an ASI up to the stall system) both the A/C normal ASI and stall warning see almost the same pressure and read the same value. As the angle of attack increases the air separation transition point (-VE pressure moves down the leading edge) and it is this suction that operates the switch as the stall is approached. With the trial ASI still connected, at this point it reads zero or below with the ASI pointer on the stop. Next test flight will be conducted with a +VE and -VE 5” water gauge connected to the stall system to measure the actual +VE and -VE pressures. This work is being done as part of the Permit work for the UK MG test flight programme as the LAA are insisting on a stall warning system on the motor glider. On trying to use the standard EUROPA XS system we are having trouble getting the switch to work consistently. Note: the wing LE profile of the MG is different to the XS and the stall speed is much lower at 42 KIAS at max 1370 lbs lower with the airbrake just cracked open. On my machine, the stall is very benign with very little airframe buffet.
 
Regards
 
Ian Cook
G-CBHI MG

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Bud Yerly
Sent: 29 June 2017 03:23
To: europa-list(at)matronics.com
Subject: RE: Re: Stall Warner - switch problems



Kelvin,
The switch is a pressure switch. With the relative wind nearly straight on the air into the tube is under suction. The switch is assembled to the hose to the leading edge using its pressure side. The switch is normally open so with suction on the tube, the light is off at low angles.

At about 14 degrees angle of attack the switch is now under pressure from the ram air. The switch is normally open and at about 3 inches of water ish, the switch will close and allow current to flow to the light/horn.

Once you land, and the speed diminishes, the pressure drops and the switch opens and the horn goes off.

Not rocket science.

See photo below:
Regards,
Bud Yerly[img]cid:image001.png(at)01D2F0C2.29A422B0[/img]

Sent from Mail for Windows 10

From: Kelvin Weston (kelv(at)kdweston.biz)
Sent: Tuesday, June 20, 2017 5:03 PM
To: europa-list(at)matronics.com (europa-list(at)matronics.com)
Subject: Re: Stall Warner - switch problems


--> Europa-List message posted by: "Kelvin Weston" <kelv(at)kdweston.biz (kelv(at)kdweston.biz)>

Hi Bud and all

Now I am really confused. I have fitted the Europa stall warning mod and switch but not yet used in anger.

How is this switch designed to work?

Is it normally closed and held open by pressure above a certain speed.
Or is it normally open and is closed by low pressure (vacuum), like a conventional Cessna stall warner, caused by the angle of the wing.

The mod leaflet suggests it is operated by vacuum, but your description of it being on until above a certain speed suggests the first option.
The switch has a hose connection to both sides of what I assume is a diaphragm, so it is easy to connect incorrectly.

If it is normally closed then does that result in the buzzer operating continually on the ground until above the stall speed?
I think that would eventually get to be a bit of a pain, especially during long holds on the ground.

--------
Regards

Kelv Weston
Kit 497
kelv(at)kdweston.biz (kelv(at)kdweston.biz)




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Location: Hampshire, UK

PostPosted: Thu Jun 29, 2017 11:47 am    Post subject: Re: Stall Warner - switch problems Reply with quote

Hi Bud

I think I might have to go with Ian on this one.

The Europa Mod 61 leaflet does state:
Inside the fuselage an adjustable vacuum switch, triggered by reduced pressure in the line

It also describes connecting the hose to the same side of the switch as the terminals.

Looking at the tech details on the switch, this is side A and should have vacuum applied to operate the switch.


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Kelv Weston
Kit 497
kelv@kdweston.biz
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PostPosted: Sat Jul 01, 2017 9:44 am    Post subject: Stall Warner - switch problems Reply with quote

A thousand apologies. Writing late at night to get a quick answer is not good .
It is a vacuum hookup in the Europa Mod 61, and normally open. Once you go past the angle, you get suction and the interior wing is positive pressure so the switch closes. It is pretty clear in the mod61 , I should have read it while awake eh!

Under ram pressure or no movement it is open. Once the relative wind point exceeds the angle of the tube it goes to suction prior to the stall.

Very sensitive to adjustment still. The cockpit hookup and setting it in the copilots lap does work well provided the connections are very tight. I just got into the habit of hooking it up in the wing as wires are quick and easy to hook up with a multi connector as my customers normally have lights and such in their wings. But vacuum lines or pitot-static lines are just as easy to hook up with the right connectors. The switch will need a service loop for the adjustment tinkering in the cockpit is all. Clean up after install in the fuselage.

Sorry if I added confusion.

Best Regards,
Bud Yerly

Sent from Mail for Windows 10

From: Kelvin Weston (kelv(at)kdweston.biz)
Sent: Thursday, June 29, 2017 3:52 PM
To: europa-list(at)matronics.com (europa-list(at)matronics.com)
Subject: Re: Stall Warner - switch problems


--> Europa-List message posted by: "Kelvin Weston" <kelv(at)kdweston.biz>

Hi Bud

I think I might have to go with Ian on this one.

The Europa Mod 61 leaflet does state:
Inside the fuselage an adjustable vacuum switch, triggered by reduced pressure in the line

It also describes connecting the hose to the same side of the switch as the terminals.

Looking at the tech details on the switch, this is side A and should have vacuum applied to operate the switch.

--------
Regards

Kelv Weston
Kit 497
kelv(at)kdweston.biz




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