Today's Message Index:
----------------------
1. 06:52 AM - Z-12 contactor failure (bsvantho)
2. 09:02 AM - Re: Z-12 contactor failure (FLYaDIVE)
3. 09:27 AM - Re: Z-12 contactor failure (Bob Verwey)
4. 10:43 AM - Re: Z-12 contactor failure (FLYaDIVE)
5. 10:53 AM - Re: Z-12 contactor failure (Alec Myers)
6. 11:38 AM - Re: Z-12 contactor failure (FLYaDIVE)
7. 12:19 PM - Re: Z-12 contactor failure (bsvantho)
8. 01:30 PM - Re: Re: Z-12 contactor failure (FLYaDIVE)
9. 01:49 PM - Re: Re: Z-12 contactor failure (Charlie England)
10. 02:13 PM - Re: Z-12 contactor failure (bsvantho)
11. 02:51 PM - Re: Re: Z-12 contactor failure (Charlie England)
12. 03:22 PM - Re: Re: Z-12 contactor failure (Robert L. Nuckolls, III)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Z-12 contactor failure |
I know it is not a likely case, but I have experienced a contactor failure on a
production plane in flight. It ended up that the root cause was a defective
master switch - but the result was the same. Because there was no endurance
bus alternate feed, it was a full electrical shutdown, in IMC no less!
I would like to know if there is a practical way to protect for contactor failure
( other than battery only operation ) with the Z-12 design. It would be nice
to have a second path to the battery from aux alternator to ensure stable power
if the master does fail. The appeal to me of having an aux alternator is
to be able to continue flight on one alternator. This is only possible if either
a battery connection is maintained always or it is a guarantee the alternator
will provide stable power without a battery connection.
The Z-13/8 uses a relay with the SD-8 alternator to connect directly to battery.
Is this design practical or even advisable with the SD-20 alternator? With
Z-13/8 the aux alternator will provide power to battery bus and E-BUS if contactor
fails.
Thoughts?
Thanks,
-Brendon
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479453#479453
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Brendon:
If the Master Switch failed why reinvent the wheel?
Since this was a certified plane you are forced to work with the design of
the time.
What I have found is 99.982% of certified plane owners and A&P's, NEVER
address the Master Switch during Annual.
It should be addressed every Annual and it is very easy to do:
1 - Spray the heck out of it with Contact Cleaner.
2 - Cycle the switch a couple of dozen times.
3 - Spray it with WD-40.
Side Note: This also goes for the micro-switch in the Stall Warning System.
On Experimental Aircraft you have a HUGE ADVANTAGE...
Use a Heavy Duty Master Switch and a Separate Heavy Duty Alternator Switch.
I use DPST switches and tie BOTH sides together. This DOUBLES the physical
as well as the electrical rating of the switch.
Want to go extra fancy? Look for switches that are Sliver Plated.
You can also use switches that have a built in Dust/Moisture shield.
OR... Install the dust/Moisture shield over the Toggle Lever.
Side Note: On certified planes with the standard split Master/Alt Switch,
there are four (4) failure points:
1 - The Physical snap action of the switch.
2 - The Electrical contacts of the switch.
3 - Fast-On tabs on the back of the switch.
4 - The Physical MOUNTING of the switch. There is a snap in bezel that
holds the switch into the panel.
This bezel fails as the ears either break off or loose their spring action.
Then the switch vibrates forward and shorts out to the aluminum panel.
The cure is to use two (2) sheet metal round head screws on either side to
hold the bezel in place.
If the switch vibrates out it will short out and take your Master/Alt
switch and Starter Relay out of the circuit.
If you are airborne - You loose even the ability to go to Battery Back-up.
Or do an in-flight re-start.
Scary!
Barry
On Fri, Apr 20, 2018 at 9:52 AM, bsvantho <bsvantho@gmail.com> wrote:
>
> I know it is not a likely case, but I have experienced a contactor failure
> on a production plane in flight. It ended up that the root cause was a
> defective master switch - but the result was the same. Because there was
> no endurance bus alternate feed, it was a full electrical shutdown, in IMC
> no less!
>
> I would like to know if there is a practical way to protect for contactor
> failure ( other than battery only operation ) with the Z-12 design. It
> would be nice to have a second path to the battery from aux alternator to
> ensure stable power if the master does fail. The appeal to me of having an
> aux alternator is to be able to continue flight on one alternator. This is
> only possible if either a battery connection is maintained always or it is
> a guarantee the alternator will provide stable power without a battery
> connection.
>
> The Z-13/8 uses a relay with the SD-8 alternator to connect directly to
> battery. Is this design practical or even advisable with the SD-20
> alternator? With Z-13/8 the aux alternator will provide power to battery
> bus and E-BUS if contactor fails.
>
> Thoughts?
>
> Thanks,
> -Brendon
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=479453#479453
>
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Barry I can't see how applying a lubricant like WD40 can be advantageous to
the contacts on the switch...surely there will be burning volatiles or lube
which would affect the service or life of the part? On the moving parts yes
but I don't know of a way to differentiate with a spray can.
On Fri, 20 Apr 2018, 6:13 PM FLYaDIVE <flyadive@gmail.com> wrote:
> Brendon:
>
> If the Master Switch failed why reinvent the wheel?
> Since this was a certified plane you are forced to work with the design of
> the time.
> What I have found is 99.982% of certified plane owners and A&P's, NEVER
> address the Master Switch during Annual.
> It should be addressed every Annual and it is very easy to do:
> 1 - Spray the heck out of it with Contact Cleaner.
> 2 - Cycle the switch a couple of dozen times.
> 3 - Spray it with WD-40.
>
> Side Note: This also goes for the micro-switch in the Stall Warning
> System.
>
>
> On Experimental Aircraft you have a HUGE ADVANTAGE...
> Use a Heavy Duty Master Switch and a Separate Heavy Duty Alternator Switch.
> I use DPST switches and tie BOTH sides together. This DOUBLES the
> physical as well as the electrical rating of the switch.
> Want to go extra fancy? Look for switches that are Sliver Plated.
> You can also use switches that have a built in Dust/Moisture shield.
> OR... Install the dust/Moisture shield over the Toggle Lever.
>
> Side Note: On certified planes with the standard split Master/Alt Switch,
> there are four (4) failure points:
> 1 - The Physical snap action of the switch.
> 2 - The Electrical contacts of the switch.
> 3 - Fast-On tabs on the back of the switch.
> 4 - The Physical MOUNTING of the switch. There is a snap in bezel that
> holds the switch into the panel.
> This bezel fails as the ears either break off or loose their spring action.
> Then the switch vibrates forward and shorts out to the aluminum panel.
> The cure is to use two (2) sheet metal round head screws on either side
> to hold the bezel in place.
> If the switch vibrates out it will short out and take your Master/Alt
> switch and Starter Relay out of the circuit.
> If you are airborne - You loose even the ability to go to Battery Back-up.
> Or do an in-flight re-start.
> Scary!
>
>
> Barry
>
>
> On Fri, Apr 20, 2018 at 9:52 AM, bsvantho <bsvantho@gmail.com> wrote:
>
>>
>> I know it is not a likely case, but I have experienced a contactor
>> failure on a production plane in flight. It ended up that the root cause
>> was a defective master switch - but the result was the same. Because
>> there was no endurance bus alternate feed, it was a full electrical
>> shutdown, in IMC no less!
>>
>> I would like to know if there is a practical way to protect for contactor
>> failure ( other than battery only operation ) with the Z-12 design. It
>> would be nice to have a second path to the battery from aux alternator to
>> ensure stable power if the master does fail. The appeal to me of having an
>> aux alternator is to be able to continue flight on one alternator. This is
>> only possible if either a battery connection is maintained always or it is
>> a guarantee the alternator will provide stable power without a battery
>> connection.
>>
>> The Z-13/8 uses a relay with the SD-8 alternator to connect directly to
>> battery. Is this design practical or even advisable with the SD-20
>> alternator? With Z-13/8 the aux alternator will provide power to battery
>> bus and E-BUS if contactor fails.
>>
>> Thoughts?
>>
>> Thanks,
>> -Brendon
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=479453#479453
>>
>>
>>
>>
>>
>>
>> ===================================
>> -
>> Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/
>> Navigator?AeroElectric-List
>> ===================================
>> FORUMS -
>> eferrer" target="_blank">http://forums.matronics.com
>> ===================================
>> WIKI -
>> errer" target="_blank">http://wiki.matronics.com
>> ===================================
>> b Site -
>> -Matt Dralle, List Admin.
>> rel="noreferrer" target="_blank">http://www.matronics.com/contribution
>> ===================================
>>
>>
>>
>>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Bob:
Yup! There are all sorts of 'possible' possibilities, all without proof,
but it DOES WORK!
Many of our aircraft are 40+ years old. The original lubricants in the
switches have long disappeared.
They are NOT sealed switches.
What has worked for many years are now failing. Just look Brandon's post.
And, when it comes to the Stall Warning micro switch - Replacement with NEW
is $1200+ used, about $600 to $700.
All this can be prevented with a can of WD-40!
Not needed on sealed DPST Toggle Switches. AND they are NOT 40+ years old.
Barry
On Fri, Apr 20, 2018 at 12:25 PM, Bob Verwey <bob.verwey@gmail.com> wrote:
> Barry I can't see how applying a lubricant like WD40 can be advantageous
> to the contacts on the switch...surely there will be burning volatiles or
> lube which would affect the service or life of the part? On the moving
> parts yes but I don't know of a way to differentiate with a spray can.
>
> On Fri, 20 Apr 2018, 6:13 PM FLYaDIVE <flyadive@gmail.com> wrote:
>
>> Brendon:
>>
>> If the Master Switch failed why reinvent the wheel?
>> Since this was a certified plane you are forced to work with the design
>> of the time.
>> What I have found is 99.982% of certified plane owners and A&P's, NEVER
>> address the Master Switch during Annual.
>> It should be addressed every Annual and it is very easy to do:
>> 1 - Spray the heck out of it with Contact Cleaner.
>> 2 - Cycle the switch a couple of dozen times.
>> 3 - Spray it with WD-40.
>>
>> Side Note: This also goes for the micro-switch in the Stall Warning
>> System.
>>
>>
>> On Experimental Aircraft you have a HUGE ADVANTAGE...
>> Use a Heavy Duty Master Switch and a Separate Heavy Duty Alternator
>> Switch.
>> I use DPST switches and tie BOTH sides together. This DOUBLES the
>> physical as well as the electrical rating of the switch.
>> Want to go extra fancy? Look for switches that are Sliver Plated.
>> You can also use switches that have a built in Dust/Moisture shield.
>> OR... Install the dust/Moisture shield over the Toggle Lever.
>>
>> Side Note: On certified planes with the standard split Master/Alt
>> Switch, there are four (4) failure points:
>> 1 - The Physical snap action of the switch.
>> 2 - The Electrical contacts of the switch.
>> 3 - Fast-On tabs on the back of the switch.
>> 4 - The Physical MOUNTING of the switch. There is a snap in bezel that
>> holds the switch into the panel.
>> This bezel fails as the ears either break off or loose their spring
>> action.
>> Then the switch vibrates forward and shorts out to the aluminum panel.
>> The cure is to use two (2) sheet metal round head screws on either side
>> to hold the bezel in place.
>> If the switch vibrates out it will short out and take your Master/Alt
>> switch and Starter Relay out of the circuit.
>> If you are airborne - You loose even the ability to go to Battery Back-up.
>> Or do an in-flight re-start.
>> Scary!
>>
>>
>> Barry
>>
>>
>>
>>
>>
>> On Fri, Apr 20, 2018 at 9:52 AM, bsvantho <bsvantho@gmail.com> wrote:
>>
>>>
>>> I know it is not a likely case, but I have experienced a contactor
>>> failure on a production plane in flight. It ended up that the root cause
>>> was a defective master switch - but the result was the same. Because
>>> there was no endurance bus alternate feed, it was a full electrical
>>> shutdown, in IMC no less!
>>>
>>> I would like to know if there is a practical way to protect for
>>> contactor failure ( other than battery only operation ) with the Z-12
>>> design. It would be nice to have a second path to the battery from aux
>>> alternator to ensure stable power if the master does fail. The appeal to
>>> me of having an aux alternator is to be able to continue flight on one
>>> alternator. This is only possible if either a battery connection is
>>> maintained always or it is a guarantee the alternator will provide stable
>>> power without a battery connection.
>>>
>>> The Z-13/8 uses a relay with the SD-8 alternator to connect directly to
>>> battery. Is this design practical or even advisable with the SD-20
>>> alternator? With Z-13/8 the aux alternator will provide power to battery
>>> bus and E-BUS if contactor fails.
>>>
>>> Thoughts?
>>>
>>> Thanks,
>>> -Brendon
>>>
>>>
>>>
>>>
>>> Read this topic online here:
>>>
>>> http://forums.matronics.com/viewtopic.php?p=479453#479453
>>>
>>>
>>>
>>>
>>>
>>>
>>> ==========
>>> -
>>> Electric-List" rel="noreferrer" target="_blank">http://www.
>>> matronics.com/Navigator?AeroElectric-List
>>> ==========
>>> FORUMS -
>>> eferrer" target="_blank">http://forums.matronics.com
>>> ==========
>>> WIKI -
>>> errer" target="_blank">http://wiki.matronics.com
>>> ==========
>>> b Site -
>>> -Matt Dralle, List Admin.
>>> rel="noreferrer" target="_blank">http://www.matronics.com/contribution
>>> ==========
>>>
>>>
>>>
>>>
>>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Calling WD40 "a lubricant" is like calling a 1969 Chateauneuf a liquid!
On Apr 20, 2018, at 1:41 PM, FLYaDIVE <flyadive@gmail.com> wrote:
Bob:
Yup! There are all sorts of 'possible' possibilities, all without proof, but it
DOES WORK!
Many of our aircraft are 40+ years old. The original lubricants in the switches
have long disappeared.
They are NOT sealed switches.
What has worked for many years are now failing. Just look Brandon's post.
And, when it comes to the Stall Warning micro switch - Replacement with NEW is
$1200+ used, about $600 to $700.
All this can be prevented with a can of WD-40!
Not needed on sealed DPST Toggle Switches. AND they are NOT 40+ years old.
Barry
On Fri, Apr 20, 2018 at 12:25 PM, Bob Verwey <bob.verwey@gmail.com> wrote:
Barry I can't see how applying a lubricant like WD40 can be advantageous to the
contacts on the switch...surely there will be burning volatiles or lube which
would affect the service or life of the part? On the moving parts yes but I don't
know of a way to differentiate with a spray can.
On Fri, 20 Apr 2018, 6:13 PM FLYaDIVE <flyadive@gmail.com> wrote:
Brendon:
If the Master Switch failed why reinvent the wheel?
Since this was a certified plane you are forced to work with the design of the
time.
What I have found is 99.982% of certified plane owners and A&P's, NEVER address
the Master Switch during Annual.
It should be addressed every Annual and it is very easy to do:
1 - Spray the heck out of it with Contact Cleaner.
2 - Cycle the switch a couple of dozen times.
3 - Spray it with WD-40.
Side Note: This also goes for the micro-switch in the Stall Warning System.
On Experimental Aircraft you have a HUGE ADVANTAGE...
Use a Heavy Duty Master Switch and a Separate Heavy Duty Alternator Switch.
I use DPST switches and tie BOTH sides together. This DOUBLES the physical as
well as the electrical rating of the switch.
Want to go extra fancy? Look for switches that are Sliver Plated.
You can also use switches that have a built in Dust/Moisture shield. OR... Install
the dust/Moisture shield over the Toggle Lever.
Side Note: On certified planes with the standard split Master/Alt Switch, there
are four (4) failure points:
1 - The Physical snap action of the switch.
2 - The Electrical contacts of the switch.
3 - Fast-On tabs on the back of the switch.
4 - The Physical MOUNTING of the switch. There is a snap in bezel that holds
the switch into the panel.
This bezel fails as the ears either break off or loose their spring action.
Then the switch vibrates forward and shorts out to the aluminum panel.
The cure is to use two (2) sheet metal round head screws on either side to hold
the bezel in place.
If the switch vibrates out it will short out and take your Master/Alt switch and
Starter Relay out of the circuit.
If you are airborne - You loose even the ability to go to Battery Back-up.
Or do an in-flight re-start.
Scary!
Barry
On Fri, Apr 20, 2018 at 9:52 AM, bsvantho <bsvantho@gmail.com> wrote:
I know it is not a likely case, but I have experienced a contactor failure on a
production plane in flight. It ended up that the root cause was a defective
master switch - but the result was the same. Because there was no endurance
bus alternate feed, it was a full electrical shutdown, in IMC no less!
I would like to know if there is a practical way to protect for contactor failure
( other than battery only operation ) with the Z-12 design. It would be nice
to have a second path to the battery from aux alternator to ensure stable power
if the master does fail. The appeal to me of having an aux alternator is
to be able to continue flight on one alternator. This is only possible if either
a battery connection is maintained always or it is a guarantee the alternator
will provide stable power without a battery connection.
The Z-13/8 uses a relay with the SD-8 alternator to connect directly to battery.
Is this design practical or even advisable with the SD-20 alternator? With
Z-13/8 the aux alternator will provide power to battery bus and E-BUS if contactor
fails.
Thoughts?
Thanks,
-Brendon
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479453#479453
==========
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
==========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
==========
WIKI -
errer" target="_blank">http://wiki.matronics.com
==========
b Site -
-Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
==========
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Not calling it a lubricant is proof you consumed too much 1969 Chateauneuf.
I guess you don't call soapstone a lubricant either!
On Fri, Apr 20, 2018 at 1:52 PM, Alec Myers <alec@alecmyers.com> wrote:
>
> Calling WD40 "a lubricant" is like calling a 1969 Chateauneuf =9Ca
liquid=9D!
>
>
> On Apr 20, 2018, at 1:41 PM, FLYaDIVE <flyadive@gmail.com> wrote:
>
> Bob:
>
> Yup! There are all sorts of 'possible' possibilities, all without proof,
> but it DOES WORK!
> Many of our aircraft are 40+ years old. The original lubricants in the
> switches have long disappeared.
> They are NOT sealed switches.
> What has worked for many years are now failing. Just look Brandon's post
.
> And, when it comes to the Stall Warning micro switch - Replacement with
> NEW is $1200+ used, about $600 to $700.
> All this can be prevented with a can of WD-40!
>
> Not needed on sealed DPST Toggle Switches. AND they are NOT 40+ years ol
d.
>
> Barry
>
> On Fri, Apr 20, 2018 at 12:25 PM, Bob Verwey <bob.verwey@gmail.com> wrote
:
> Barry I can't see how applying a lubricant like WD40 can be advantageous
> to the contacts on the switch...surely there will be burning volatiles or
> lube which would affect the service or life of the part? On the moving
> parts yes but I don't know of a way to differentiate with a spray can.
>
> On Fri, 20 Apr 2018, 6:13 PM FLYaDIVE <flyadive@gmail.com> wrote:
> Brendon:
>
> If the Master Switch failed why reinvent the wheel?
> Since this was a certified plane you are forced to work with the design o
f
> the time.
> What I have found is 99.982% of certified plane owners and A&P's, NEVER
> address the Master Switch during Annual.
> It should be addressed every Annual and it is very easy to do:
> 1 - Spray the heck out of it with Contact Cleaner.
> 2 - Cycle the switch a couple of dozen times.
> 3 - Spray it with WD-40.
>
> Side Note: This also goes for the micro-switch in the Stall Warning
> System.
>
>
> On Experimental Aircraft you have a HUGE ADVANTAGE...
> Use a Heavy Duty Master Switch and a Separate Heavy Duty Alternator Switc
h.
> I use DPST switches and tie BOTH sides together. This DOUBLES the
> physical as well as the electrical rating of the switch.
> Want to go extra fancy? Look for switches that are Sliver Plated.
> You can also use switches that have a built in Dust/Moisture shield.
> OR... Install the dust/Moisture shield over the Toggle Lever.
>
> Side Note: On certified planes with the standard split Master/Alt Switch
,
> there are four (4) failure points:
> 1 - The Physical snap action of the switch.
> 2 - The Electrical contacts of the switch.
> 3 - Fast-On tabs on the back of the switch.
> 4 - The Physical MOUNTING of the switch. There is a snap in bezel that
> holds the switch into the panel.
> This bezel fails as the ears either break off or loose their spring actio
n.
> Then the switch vibrates forward and shorts out to the aluminum panel.
> The cure is to use two (2) sheet metal round head screws on either side
> to hold the bezel in place.
> If the switch vibrates out it will short out and take your Master/Alt
> switch and Starter Relay out of the circuit.
> If you are airborne - You loose even the ability to go to Battery Back-up
.
> Or do an in-flight re-start.
> Scary!
>
>
> Barry
>
>
> On Fri, Apr 20, 2018 at 9:52 AM, bsvantho <bsvantho@gmail.com> wrote:
>
> I know it is not a likely case, but I have experienced a contactor failur
e
> on a production plane in flight. It ended up that the root cause was a
> defective master switch - but the result was the same. Because there wa
s
> no endurance bus alternate feed, it was a full electrical shutdown, in IM
C
> no less!
>
> I would like to know if there is a practical way to protect for contactor
> failure ( other than battery only operation ) with the Z-12 design. It
> would be nice to have a second path to the battery from aux alternator to
> ensure stable power if the master does fail. The appeal to me of having
an
> aux alternator is to be able to continue flight on one alternator. This
is
> only possible if either a battery connection is maintained always or it i
s
> a guarantee the alternator will provide stable power without a battery
> connection.
>
> The Z-13/8 uses a relay with the SD-8 alternator to connect directly to
> battery. Is this design practical or even advisable with the SD-20
> alternator? With Z-13/8 the aux alternator will provide power to batter
y
> bus and E-BUS if contactor fails.
>
> Thoughts?
>
> Thanks,
> -Brendon
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=479453#479453
>
>
> ==========
> -
> Electric-List" rel="noreferrer" target="_blank">http://www.
> matronics.com/Navigator?AeroElectric-List
> ==========
> FORUMS -
> eferrer" target="_blank">http://forums.matronics.com
> ==========
> WIKI -
> errer" target="_blank">http://wiki.matronics.com
> ==========
> b Site -
> -Matt Dralle, List Admin.
> rel="noreferrer" target="_blank">http://www.matronics.com/contributio
n
> ==========
>
>
===========
===========
===========
===========
===========
>
>
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Agree the certified electrical system is much weaker and I found first hand that
master switches are not well maintained, but I will attempt to bring this back
around to the intent of my original post...
Not trying to reinvent anything. This will most likely remain a philosophical
discussion for me as Z-12 is already quite robust as compared to the certified
planes I fly in that E-bus devices will still be available on battery + internal
battery backups, etc.
I have found very little information specific to protecting for master contactor
failure. So is the philosophy for Z-12 that it is not worth worrying about
since E-bus will still operate? I can accept this, I just am confused when I
see Z-13/8 that connects the alternator on the battery side. Can anyone explain
the reason for the difference?
Thanks,
-Brendon
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479462#479462
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
Brendon:
Here is the schematic of the Z-13/8
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z13-8T.pdf
The NOTES are not on this schematic.
But, you can see the Alternator is on the LOAD side of Relay / Battery
Contactor. So, the relay has to be closed
for Alternator to function.
I could not find a link for the Z-12 ;-(
But, consider this:
Many people like a Avionics Master Switch.
The switch itself has a BACK-UP.
It is usually a SECOND heavy duty switch either in Parallel with the main
Avionics Master Switch <-- Used when the Main switch is the ONLY means
closing the circuit.
The other location is across a Avionics Master Relay. The Main Avionics
Master Switch closes a Relay <-- Not the best way of doing things but it
works. So, when the BACK-UP Avionics Master Switch is closed it bypasses
the relay and applies power to the Avionics circuit.
Using this same type of configuration you can use for the MASTER SWITCH.
Put a BACK-UP Master Switch in Parallel with the Main Master Switch. The
only problem there is you have to REMEMBER to Shut Off the MAIN MASTER
SWITCH and Double Check that the BACK-UP switch is OFF.
Totally doable on Experimental. Not doable on certified, not without a 337!
Barry
On Fri, Apr 20, 2018 at 3:18 PM, bsvantho <bsvantho@gmail.com> wrote:
>
> Agree the certified electrical system is much weaker and I found first
> hand that master switches are not well maintained, but I will attempt to
> bring this back around to the intent of my original post...
>
> Not trying to reinvent anything. This will most likely remain a
> philosophical discussion for me as Z-12 is already quite robust as compared
> to the certified planes I fly in that E-bus devices will still be available
> on battery + internal battery backups, etc.
>
> I have found very little information specific to protecting for master
> contactor failure. So is the philosophy for Z-12 that it is not worth
> worrying about since E-bus will still operate? I can accept this, I just
> am confused when I see Z-13/8 that connects the alternator on the battery
> side. Can anyone explain the reason for the difference?
>
> Thanks,
>
> -Brendon
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=479462#479462
>
>
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
On 4/20/2018 2:18 PM, bsvantho wrote:
>
> Agree the certified electrical system is much weaker and I found first hand that
master switches are not well maintained, but I will attempt to bring this
back around to the intent of my original post...
>
> Not trying to reinvent anything. This will most likely remain a philosophical
discussion for me as Z-12 is already quite robust as compared to the certified
planes I fly in that E-bus devices will still be available on battery + internal
battery backups, etc.
>
> I have found very little information specific to protecting for master contactor
failure. So is the philosophy for Z-12 that it is not worth worrying about
since E-bus will still operate? I can accept this, I just am confused when
I see Z-13/8 that connects the alternator on the battery side. Can anyone explain
the reason for the difference?
>
> Thanks,
>
> -Brendon
>
I *think* that what you're seeing in z13-8 is that the primary alt is
connected conventionally, to the bus side of the master contactor. The
*backup* (much lower current capability) alt is connected to the battery
side of the contactor, so that in the event of a primary alt failure,
you can shed the load of the main bus *and* the load of the master
contactor (coil consumes 1/2-1 1/2 amps just to keep it engaged), and
still have the backup alt available to sustain the battery bus and
endurance bus. If it was on the other side of the master contactor, you
couldn't shed the main bus and contactor loads in the event of a main
alt failure.
Charlie
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
ceengland7(at)gmail.com wrote:
> On 4/20/2018 2:18 PM, bsvantho wrote:
>
> >
> >
> > Agree the certified electrical system is much weaker and I found first hand
that master switches are not well maintained, but I will attempt to bring this
back around to the intent of my original post...
> >
> > Not trying to reinvent anything. This will most likely remain a philosophical
discussion for me as Z-12 is already quite robust as compared to the certified
planes I fly in that E-bus devices will still be available on battery +
internal battery backups, etc.
> >
> > I have found very little information specific to protecting for master contactor
failure. So is the philosophy for Z-12 that it is not worth worrying about
since E-bus will still operate? I can accept this, I just am confused when
I see Z-13/8 that connects the alternator on the battery side. Can anyone
explain the reason for the difference?
> >
> > Thanks,
> >
> > -Brendon
> >
> > I *think* that what you're seeing in z13-8 is that the primary alt is
> >
>
> connected conventionally, to the bus side of the master contactor. The
> *backup* (much lower current capability) alt is connected to the battery
> side of the contactor, so that in the event of a primary alt failure,
> you can shed the load of the main bus *and* the load of the master
> contactor (coil consumes 1/2-1 1/2 amps just to keep it engaged), and
> still have the backup alt available to sustain the battery bus and
> endurance bus. If it was on the other side of the master contactor, you
> couldn't shed the main bus and contactor loads in the event of a main
> alt failure.
>
> Charlie
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
This makes perfect sense to me. Now look at Z-12 - the primary and backup alternators
are both connected the same way - to the main bus. If you turn off the
master both alternators are isolated from the battery. This means battery only
operation unless the alternators remain stable without battery. Why do it
this way? The only difference I see is the backup alternator is the larger 20A
vs 8A.
To ask another way. Why not connect the larger 20A backup alternator in the same
way as Z-13/8 ( with relay and switch )? Is this not advisable due to the
higher current being switched or some other reason?
-Brendon
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479466#479466
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
On 4/20/2018 4:13 PM, bsvantho wrote:
>
>
> ceengland7(at)gmail.com wrote:
>> On 4/20/2018 2:18 PM, bsvantho wrote:
>>
>>>
>>>
>>> Agree the certified electrical system is much weaker and I found first hand
that master switches are not well maintained, but I will attempt to bring this
back around to the intent of my original post...
>>>
>>> Not trying to reinvent anything. This will most likely remain a philosophical
discussion for me as Z-12 is already quite robust as compared to the certified
planes I fly in that E-bus devices will still be available on battery +
internal battery backups, etc.
>>>
>>> I have found very little information specific to protecting for master contactor
failure. So is the philosophy for Z-12 that it is not worth worrying
about since E-bus will still operate? I can accept this, I just am confused
when I see Z-13/8 that connects the alternator on the battery side. Can anyone
explain the reason for the difference?
>>>
>>> Thanks,
>>>
>>> -Brendon
>>>
>>> I *think* that what you're seeing in z13-8 is that the primary alt is
>>>
>> connected conventionally, to the bus side of the master contactor. The
>> *backup* (much lower current capability) alt is connected to the battery
>> side of the contactor, so that in the event of a primary alt failure,
>> you can shed the load of the main bus *and* the load of the master
>> contactor (coil consumes 1/2-1 1/2 amps just to keep it engaged), and
>> still have the backup alt available to sustain the battery bus and
>> endurance bus. If it was on the other side of the master contactor, you
>> couldn't shed the main bus and contactor loads in the event of a main
>> alt failure.
>>
>> Charlie
>>
>> ---
>> This email has been checked for viruses by Avast antivirus software.
>> https://www.avast.com/antivirus
>
> This makes perfect sense to me. Now look at Z-12 - the primary and backup alternators
are both connected the same way - to the main bus. If you turn off
the master both alternators are isolated from the battery. This means battery
only operation unless the alternators remain stable without battery. Why do it
this way? The only difference I see is the backup alternator is the larger
20A vs 8A.
>
> To ask another way. Why not connect the larger 20A backup alternator in the
same way as Z-13/8 ( with relay and switch )? Is this not advisable due to the
higher current being switched or some other reason?
>
> -Brendon
I'd bet that the reason is implied in the text descriptions preceding
the drawings. With the bigger backup alt, there's no reason to turn off
the master (except fire, in which case you want the alternators off line
just like the rest of the electrical system). Note also that the larger
backup alt uses an external regulator to supply field voltage, so the
regulator would have to be moved to the endurance bus, as well, if you
intend to shut off the master & keep the backup on line.
I confess it's been a while since I studied the diagrams, but they've
endured for quite a while with people prodding at them, so I suspect
that the real issue is discovering the logic, rather than questioning
whether there is logic. :-)
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Z-12 contactor failure |
At 03:28 PM 4/20/2018, you wrote:
>Brendon:
>
>Here is the schematic of the Z-13/8
>
><http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z13-8T.pdf>http://
www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z13-8T.pdf
>
>The NOTES are not on this schematic.
>
>But, you can see the Alternator is on the LOAD
>side of Relay / Battery Contactor.=C2 So, the relay has to be closed=C2
>for Alternator to function.
not necessarily so . . . some alternators
need some help from the battery to get
started but once excited and on-line, they
will continue to function even if the battery
contactor is opened
Bonanzas and Barons are fitted with alternators
that self excite . . . the alternator(s) and
battery are on separate switches. The POH speaks
to alternator-only operations which are permissable.
The e-bus is a work-around for contactor failure.
The s/b alternator in z13/8 will come on line
whether or not the battery contactor is closed.
Contactor failure in flight is exceedingly rare.
A contactor that's going bad will offer some issues
for getting the engine started . . . your FIRST
and very valuable clue that it's time to change
the puppy out.
So what's the source of the heartburn over contactor
failures?
Bob . . .
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|