I know that wire sizes are posted but I can't find the size for the different circuits in my books that I have. I even looked for the fuse size for each circuit and that eludes me. I am replacing all the wing wiring and need to know what size for the wingtip, landing[2] lights, and the proposed 75 watt heated pitot. Please help!
Thanks,
John-n3833v
170 Wiring circuits
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
-
GAHorn
- Posts: 21290
- Joined: Fri Apr 12, 2002 8:45 pm
Did you look in The MX Library under "electrical wiring"?
The formula W=VA will assist you in deciding the size CB to use in various circuits.
In the case of your Pitot heat, 75 Watts divided by 14 volts equals 5.37 Amps. So a 7.5 or 10 Amp breaker should work just fine. Then all you have to do is make sure to use the correct wire size to support wichever CB you use. I.E., a 10 AMP breaker would protect an 18 ga. wire.
The formula W=VA will assist you in deciding the size CB to use in various circuits.
In the case of your Pitot heat, 75 Watts divided by 14 volts equals 5.37 Amps. So a 7.5 or 10 Amp breaker should work just fine. Then all you have to do is make sure to use the correct wire size to support wichever CB you use. I.E., a 10 AMP breaker would protect an 18 ga. wire.
-
N1277D
- Posts: 246
- Joined: Wed Apr 24, 2002 6:24 pm
Wire Size
If I remember correctly FAA publication AC43 has a chart in it that provides the wire size (ga) as a function of it's length and the max expected current. Wire size also depends on if the wire is a single strand or contained in a bundle. AC43 is a huge document that can be downloaded from the FAA's web page. http://www.faa.gov
Cessna® is a registered trademark of Textron Aviation, Inc. The International Cessna® 170 Association is an independent owners/operators association dedicated to C170 aircraft and early O-300-powered C172s. We are not affiliated with Cessna® or Textron Aviation, Inc. in any way.