Please review my electrical system

[Jamie Aust]

Hello All,

I have been working on this for some time now, I would like to get feedback to see if this will be ok. I hope to NOT get any blue smoke !

What I used.
windows Paint
windows Picture fax viewer ( to rotate only )

My setup. Very basic day VFR.
0-360 fixed pitch carb ( no F/I or electric ig )
acs a-510 key ignition
60 amp ANL fuse and Dynon shunt on firewall.
No avionics master. My check list has them turned off before start/shutdown.

From other electrical systems I have seen , they all tend to use switches instead of a keyed ignition, so this is to help myself and others that might need a clear way to wire it up.

I have not put any devices in as yet, onto the main bus for two reasons.
1) I wanted a clean template. ( so others can used this template if suitable )
2) its easy to edit them in latter.

Item that will be going on the main buss are:
Efis - skyview 10"
Comm - Icom A200
Txpdr - Gtx327
Flap
Boost pump
Intercom - Spa400
lights - strobe/Nav.

The large ( Fat wires ) I have dont seem to be very flexible, has anyone used welding wire or 4x4 battery wire , both are very flexible.



That is the best I can do with the picture, my original file is a 5meg Bmp file, can anyone help with hosting that file size/format ?

[AltonD]

Looks efficient and will work. One suggestion, split out the avionics with an avionics master. The only reason is so they can be powered down convieniently for engine start. It is a personal preference and not required. But most that do not put in a avionics master, wish they had later.

[Bushcaddy]

Hi Jamie,

I would increase the size of the wire running from the Battery Contactor to the Master Switch, to either an 18 or 20 AWG, then a fuseable link should be added at the Battery Contactor end of that wire, these are typically wires that are four sizes smaller than the wire they protect, therefore for an 18 awg wire you would need a 22 awg fuseable link and a 24 awg fusable link for a 20 awg wire. Otherwise that wire, as shown in your drawing, is running back through the firewall unprotected. Here's a guide:http://www.aeroelectric.com/articles.../fuselink.html

[az_gila]

Originally Posted by Bushcaddy

Hi Jamie,

I would increase the size of the wire running from the Battery Contactor to the Master Switch, to either an 18 or 20 AWG, then a fuseable link should be added at the Battery Contactor end of that wire, these are typically wires that are four sizes smaller than the wire they protect, therefore for an 18 awg wire you would need a 22 awg fuseable link and a 24 awg fusable link for a 20 awg wire. Otherwise that wire, as shown in your drawing, is running back through the firewall unprotected. Here's a guide:http://www.aeroelectric.com/articles.../fuselink.html

...alone. The wire is not completely unprotected since it has the resistance of the contactor in series with the battery that would limit the current if a failure at the firewall occured.

Bob N's latest Z11 schematic shows the contactor wire as 22 gauge, and no fusible link...

http://www.aeroelectric.com/PPS/Adob..._Pdfs/Z11M.pdf

Bushcaddy's suggestions certainly won't do any harm, but are not really needed.

With regard to the previous avionics master switch suggestion -

Remember that this added switch can create a single point failure for all of your avionics, so if you do add it, at least use a double pole switch and wire both of the poles in parallel.

[Jamie Aust]

Thank you all for your reply.

I may fine tune it a bit more.
As you can see it is a Z11, but with key ignition.
So the two things for me to work out are,
1) Master to contactor wire size/ fuse-link.
2) Avionics master sw ( In the z11, I dont seem to see one here )

I would like anyone that has not put a Avoinics master switch in, to please reply.

[Guy Prevost]

I did not put an avionics master in and don't regret the decision. Just build it like you want it. It will work great and be a joy to fly either way.

Guy

[Jim P]

+ 1 on the no-avionics-master switch, and no regrets either. Would do it the same on the next project.

[L.Adamson]

It's a fact that some manufacturers prefer you to have your avionics off, when starting the engine, while some don't seem to care.

Personally, I prefer my avionics "off", and certainly don't care to turn them on or off individually. Although my avionics go through "one switch", the avionic buss is also my backup/essential buss.......which routes current around that single switch.

But what the heck, I also prefer the Cessna type batt/alt switch as opposed to other methods of individual switches. It has a built in interlock to always put the battery on line when ever the alternator is functioning.....automatically. Same goes for the regular "key start" switch too.

L.Adamson --- RV6A

[Guy Prevost]

Originally Posted by L.Adamson

It's a fact that some manufacturers prefer you to have your avionics off, when starting the engine, while some don't seem to care.

Just to be clear, I do have my avionics off during startup. I turn the radio and transponder on after start, so I have two switches to press after start instead of one. It costs me about 1 second per engine start. Still, I don't believe there's any reason not to have an avionics master if you want one. Just a matter of personal choice.

[TSwezey]

We have a avionics master but my partner insists on turning everything off anyways. Could have lived without the avionics switch. We have to turn on 4 things. Two radios, GPS and transponder and it takes a whole 10 seconds maybe.