The International Cessna^® 170 Association

I am in the process of replacing the rest of my old wiring and decided to replace my old fuse holders with CBs. I don't really have anything against the fuses (NOS fuses are still available at least for now) but in the process of replacing wiring I would have to solder the new wire on the fuse holders and my soldering skills are poor to say the least. Since I needed a backing panel to accomodate the new smaller diameter circuit breakers I made a backing panel for behind the switch panel. This actually made it very easy to preassemble and attach the wires before installing rather working behind the panel.

Very nice Karl!

Very very nice.

I don't understand how anyone capable of making such a nice job as that panel is would have any problem soldering, especially on copper wire.

blueldr wrote:I don't understand how anyone capable of making such a nice job as that panel is would have any problem soldering, especially on copper wire.

Well I could of probably gobbed the wires on there, but the idea of laying on my back with my head in the rudder pedals with liquid solder dripping on me didn't seem really appealing.

lowNslow,

Having hot solder dripping on you is only one of the reasons A&P mechanics can demand the amazingly high pay they make.

( That doctor in the next hangar will squeal like a stuck pig when you charge him $60/hr. to pull a stuck valve in his Bonanza out of the bottom spark plug hole to free it up, but he will happily pay $90/hr. for an oil chnge in his wifes Lexus.)

I would gladly re-wire a bus from fuses to breakers before crawling up under a 170's panel with a hot iron and a spool of tin.

I've never been burned by a crimper

The standard practice these days is for all wiring to be crimped . No hot solder , quick and easy PLUS not dry solder joints .

https://www.aircraft-tool.com/shop/deta ... D=E300-002

$35 for a decent ratchet crimper with replaceable dies. Work great too.
If you're only doing the occasional wire or just one plane's worth of wiring, these are the ones to get IMO.

N2625U wrote:Speaking of crimping what would you recommend for a crimper? Tired of the ones you get at the hardware store that aren't worth a politician's speech.

I bought one of the ratcheting dual jaw crimpers a few years ago from Avery or ATS (can't remember which one) at EAA a few years ago. I seem to recall it was around $40-$50, and worth every penny! With the dual jaws you get a crimp on the wire and on insulation, just like it should be. And with the ratcheting action and auto release you know when you have a good crimp. Every who works on a plane should have one of these in his toolbox.

DEM

What is the book entry for the circuit breakers? 337 with field approval, STC purchase, or something else? Your input is appreciated. Thanks, melcessna

If you are replacing the fuses for same rated circuit breakers, it's a log book entry as nothing in the system has changed.
Breakers and fuses are standard parts of similar capability.
If you add new circuits or modify existing ones, you'll need a new load calculation and possibly a 337 depending on how your mechanic feels about it.

I'd read up on the definition of major alteration that requires a 337.

Thank you

Nice job indeed. I'm in the process of a similar mod, but in an A model. Just 2 questions,1 for Kyle, and 1 in general...:

In the 2nd picture, the main bus bar covers all the breakers, minus the Land Light breaker.
- are you wiring the power to that breaker from the bar, due to the terminal setup?

In the 4th\final picture, the Gen is a 60A .
- According to the diagrams and wire numbers listed in the 170A IPC, it appears the ammeter run from Bat + , through the ammeter, directly to the bus bar.
How is the gen breaker wired into the bus bar and gen system? I have no existing harnness from which to copy, and the drawings are ok but it is hard to determine a few things
I have referred to the Cessna 100 series manual, and there are 2 drawings that are close , based on a '56 172.. one has an ammeter, and one does not.
They show the gen breaker attached to the main bus , in the same manner as all other breakers...

Rick