1 wire to 2

[Mad Mel]

Originally Posted by flattracker

During most of my 8 yr. career in the Air Force I worked on B52s (D, F, G, and H). In that time I occasionally had to replace connectors in them. Most of the wiring had connectors that were soldered. Some of the newer stuff did have crimped connectors. With rare exception when a connector got replaced it was because someone got stupid and caused damage to one. Outside of missiles going into space few electrical systems experienced a worse environment then in B52s.
I went to a class on soldering when I first started at Lockheed Missiles & Space (I started out as a technician) and learned how to crimp connectors and solder the Lockheed way. Both ways were used in missiles. I believe that crimping is used exclusively for things going to space now. (solder adds weight while crimping does not) In the early 80s my cubicle was in the High Bay of the building where the interconnecting cables for Hubble were manufactured (I walked by the special tables used and the DITMCO machine each morning and don't recall any soldering being done) If you remove any flux from a solder joint the flux issue is gone. Use isopropol alcohol with an acid brush to remove the flux (do it right after the solder cools). Don't use more solder than needed. We also learned about melt on solder connections (solder splices) where you place two wires into a special sleeve with low temp solder inside, apply heat from a heat gun and the solder makes a good connection and the plastic sleeve shrinks to form a water resistant connection.


I have seen wire nuts used in older Onan generators where the four wires are connected. The wires were connected one way for 120 vac out vs. 240 vac out.


I just looked at some crimp connectors (MVP 10) that can handle 8 gauge wire. They are crimped and the sleeve is heat shrinkable with adhesive inside. They look like a good approach.


My Generator is good for 30 amps on each 120 vac leg. I used 8 gauge wire vs. 10 gauge. 10 gauge can handle 30 amps but I like to oversize my wiring.



I used 6 gauge wire for my shore power connection rated at 50 amps. I don't like wires getting hot or even warm. I also don't want excessive voltage drop. (I know I am being obsessive)



(I used stranded wire also)

Its fun to get replies like this as it shows just how eclectic a group we have here. Your aircraft experience goes back much farther than mine. The commercial aircraft systems I worked on could only ever have a soldered wire if it was cleaned manually with Stodards Solvent to remove flux then it would have to be potted in an approved epoxy so the connection remained flexible into and out of the small block of epoxy. PROPER crimp connections with them indexed properly and using brand name pieces. With proper ratcheting Panduit type crimpers. Your must use good crimpers not the average piece of crap you get at an auto supply store.
As for wire nuts they are still a no go in a mobile environment (lol especially a generator) I have had to put out two electrical fires and repair the aftermath of shorted wiring from them pieces of crap falling off. Wire nuts are no better than twist and tape. They cannot be trusted. My bus will be getting wired with stranded wire running in 3/4 conduit. I will leave some pull cords in there for future additions (or runs I forgot to do !!!)
Thanks for your input it was very interesting....Chatting Rocket Science on a Skoolie forum is just cool.
Michael

[HamSkoolie]

Originally Posted by flattracker

...I first started at Lockheed Missiles & Space (I started out as a technician) and learned how to crimp connectors and solder the Lockheed way. Both ways were used in missiles. I believe that crimping is used exclusively for things going to space now. (solder adds weight while crimping does not)

Phantom and later Hornet Ordnance (with some Motor T and CH53 time in between). I'd like to know how crimping doesn't add weight as there is a component being crimped over the wires being joined.



Definitely no wire nuts or solid wiring in a mobile applications.



In home renovations, the first thing I do when I open an electrical fixture is toss the crappy wire nuts they supplied.


Properly done solder joints...... not cold, not allowed to wick way up the wire, proper amount of heat use of heat sinks as well as the proper flux..... are perfectly fine for many, but not all, mobile applications. I prefer the little insulated crimp caps for most work just because soldering is a pain when not on the bench.


Not sure who mentioned the taps for T'ing in but I would NEVER use one of those in ANY application except a field expedient repair to get someone to a proper repair site.

[cadillackid]

I hate wire nuts .. I’ve gone to using wago on my home projects , they have different types for different connections including specifically for stranded wire. They even have some made for a mix of solid and stranded wire. I really haven’t had any issue with crimp connectors on 12 volt stuff where a proper crimp is applied ( that means a crimp tool and not a pair of pliers).

Those little blue spliced thingies that look like mini fridges are cursed. Yeah I’m sires there’s still a few in my busses but they will fail at some point and do so in a way to have flaky connectivity

[flattracker]

Some clarification:
You don't see splices in things that go to space. The crimps were used on pins and sockets of connectors. Those crimps were made with very expensive tooling, usually pressing 3 or 4 divots into the pin or socket. Those pins and sockets were usually gold plated also. The tooling went through periodic calibration testing to assure that each crimp was correct.



I also think solid wire vs. stranded wire is OK, IF it is PROPERLY supported and NO splices are used. All of my primary wiring is run through steel conduit, just like commercial/industrial wiring. I used rain tight fittings where going through LBs under the bus. Any small electrical boxes under floor are waterproof also. It made for a lot of extra work, but I believe this exceeds the support of wiring in commercially manufactured motor homes/coaches. Issues with solid wire occur from movement and flexing. When running through conduit, the wire can't move much. Shorter lengths of wire in an electrical panel vs. longer are also better.



When I re-wired my scratch built custom shovelhead (Harley) back in the mid nineties I used teflon insulated stranded wiring, which is vast overkill. That wiring is still good. (my source of the teflon insulated wire is gone, sigh)
If you are really obsessive, it is a way to go, very expensive. Teflon will not melt off the wire even if experiencing a dead short.