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az_gila 05-02-2008 09:50 AM

Breakers
 
Sonny,

AeroElectric Bob's fuse based schematics still utilize a few breakers....

Are these on the panel, or have you hidden them somewhere?

gil A

lostpilot28 05-02-2008 07:38 PM

Quote:

Originally Posted by az_gila (Post 219702)
Sonny,

AeroElectric Bob's fuse based schematics still utilize a few breakers....

Are these on the panel, or have you hidden them somewhere?

gil A

Hi Gil,
You must've read a different Aerolectric Connection. ;) Just kidding...Bob actually says that you can use breakers, but fuses are cheaper and easier. I'm wondering why anyone would use breakers considering the cost.

Aside from that, I almost used one 60-Amp breaker for the Alt Field, but ended up deciding to use his really-big-60-Amp-fuse idea instead (mounted just like Dan C's). I like the idea of keeping the high current lines out of the cockpit.

My last airplane (Pulsar XP) had lots of RF issues and I'll do anything at this point to avoid that frustration. Even if it means doing exactly as Bob suggests by keeping the large wire runs around 6 inches...which is partially my reason for having the fuse blocks mounted way up front.

I like the idea of a flip-down panel, but that's a minor convenience. Besides, if the fuses protect the wires, and your system is wired correctly, you should never want to change a fuse (or push in a breaker) in flight. Aside from the maintenance hassle of "diving" under the panel head-first, doing it this way is preferable to me...and you should only have a couple instances where you'll have to change a fuse (shorted wire or malfunctioning equipment). I know somebody will tell me there are other reasons! ;)

Ironflight 05-02-2008 08:09 PM

Quote:

Originally Posted by lostpilot28 (Post 219839)
I know somebody will tell me there are other reasons! ;)

I have read Bob's book many times, and agree with him on about 95% of everything he says. I personally prefer circuit breakers, not so much for in-flight use, but for the fact that during installation, development, and maintenance, I frequently find that I am energizing and de-energizing circuits, over, and over again. I don't' want to mess up your thread with a debate on EFIS power during engine start, but when I turn on my Master, my EFIS and EIS boxes come up - no switches,. If I want to power cycle them for testing purposes, software loads, etc, I pull breakers. It is a whole lot easier (for me) to reach down by my knee and cycle the AHRS breaker to reboot than if I had concealed fuses. I'm not saying that this is for everyone - or anyone but myself in fact - but it is something that some folks may not have thought about. Maintenance, test, and checkout will be big parts of your life when working on an electronically-oriented experimental aircraft.

Paul

az_gila 05-02-2008 10:31 PM

AeroElctric Bob does use some breakers
 
Quote:

Originally Posted by lostpilot28 (Post 219839)
Hi Gil,
You must've read a different Aerolectric Connection. ;) Just kidding...Bob actually says that you can use breakers, but fuses are cheaper and easier. I'm wondering why anyone would use breakers considering the cost.

Aside from that, I almost used one 60-Amp breaker for the Alt Field, but ended up deciding to use his really-big-60-Amp-fuse idea instead (mounted just like Dan C's). I like the idea of keeping the high current lines out of the cockpit.

My last airplane (Pulsar XP) had lots of RF issues and I'll do anything at this point to avoid that frustration. Even if it means doing exactly as Bob suggests by keeping the large wire runs around 6 inches...which is partially my reason for having the fuse blocks mounted way up front.

I like the idea of a flip-down panel, but that's a minor convenience. Besides, if the fuses protect the wires, and your system is wired correctly, you should never want to change a fuse (or push in a breaker) in flight. Aside from the maintenance hassle of "diving" under the panel head-first, doing it this way is preferable to me...and you should only have a couple instances where you'll have to change a fuse (shorted wire or malfunctioning equipment). I know somebody will tell me there are other reasons! ;)

I only said some breakers...:D

Actually not, I read the same book.....:)....the basic Z-11 schematic shows 1 breaker - ALT FIELD, and the dual alternator/single battery option seems to show 5 on Z-12. The dual battery/Dual Alternator Z-14 uses two breakers.

Check the exact Z schematic that you intend to use.....:)

I fully agree that not bringing the heavy wire and a 60 Amp breaker/fuse inside the cabin is a good idea. The ANL is a good solution.

gil A

lostpilot28 05-03-2008 10:25 AM

Quote:

Originally Posted by az_gila (Post 219865)
... Z-11 schematic shows 1 breaker - ALT FIELD, and the dual alternator/single battery option seems to show 5 on Z-12. The dual battery/Dual Alternator Z-14 uses two breakers.

Doh! You are correct...I omitted the 5A breaker because my Alternator has internal over-voltage protection (Plane Power) do I didn't copy that part of Bob's Z-11 schematic. But, the Plane Power schematic shows having the Field Switch inline with a 5A breaker...I think originally I was just going to use a 5A fuse and didn't give it a 2nd thought. Is there any reason I should not use a fuse for this? I'm trying to think of an instance where I'll want to pull the Field breaker and reset it (in flight).

Paul, you make an excellent point. The MGL EFIS does not have a power switch so cycling would require flipping the Master switch. I'm already committed to using fuses, so my alternate thinking would be to add a switch for each EFIS. Not sure I like the idea of loading up my panel with switches, though. I can certainly see the value that you're pointing out with regards to maintenance. The good thing about my panel though is that everything else does have an on/off switch (comm, xpndr, intercom), so using the Master Switch on the ground is essentially the same thing. I'm open to further discussion on this, too...If my thinking is going down the wrong path, please let me know! :)


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