Re: Something worth looking at.

[robert Etter]

'Yesterday I was taking apart the wiring on my old firewall, and I found something that was quite scary.

For the most part, I am sure that the wiring has been in place for a long time. Possibly original from the factory. The wire type used was pretty much constant throughout the harness. They used an 18 gauge wire to supply DC voltage from the Master solenoid to the DC buss on the fuse panel. According to the chart that I looked at, an 18 gauge wire isn't even rated for 20 amps much less than the 25 amps the generator is rated for. A 16 gauge wire is barely good for 25 amps for only short runs. Once the generator goes off line, the equipment would draw what ever it wants from the battery, and that could be 30-40 amps or greater.

Then you can look at the maximum current draw for all the equipment that is installed. It gets scary.
landing light - 20 amps
radio - 10-15 amps
nav. lights - 2 amps
fuel gauge & lights - 2 amps

I am sure that I am understating the nominal current draw. That could put it close to 40 amps @ 12 vdc thru an 18 gauge wire. An 18 gauge wire isn't rated for 25 amps; 40 amps. would make for a hot time.

You could use that wire to cut or shape foam for a homebuild airplane. It would get hot in a real hurry.

Bob Etter
PO Box 974
Tonopah, NV 89049
775-482-6820
rletter@citlink.net


[Non-text portions of this message have been removed]'

[windshieldguy2000]

'Bob: Those are very good points about the wiring. We are completely
rewiring my airplane (it has a 50 amp generator) and have replaced
absolutely all the wiring and also replaced the fuses with circuit
breakers. The really scary wiring was done in the field when previous
owners added radios and other equipment. If anyone out there is
installing circuit breakers in their airplanes, I highly recommend
Peerless Electronics at 800-285-2121; they have very good prices on
Klixon breakers.

Brad Donner
NC77605'