NASA Splice standard

[Grasshopp]

Came across this in my daily reading.

http://blog.makezine.com/2012/02/28/how-to-splice-wire-to-nasa-standards/

I have tried it, and it works great for solid wire, but doesn't work very well for stranded wire. I also did a pull test on solid wire, and the wire stretched and broke before the splice even budged. It is easy to use with shrink tubing to make it water proof.

I don't know if this is very relevant to marine applications, but it was a new bit of knowledge for me.

Cheers.

 

[KD3PC]

that is/was a Western Union splice long before NASA used it....

 

[Maine Sail]

Splices consisting of wire twisting and solder are not allowed on boats built to ABYC standards.. Marine wire is finely stranded and the Western Union splice is / was designed for solid copper wire, which we do not use on boats...

 

[Steve Dion]

I always do this when I go into space, don't you?

 

[uncledom]

That splice works on anything. It's great to know in a pinch. You don't need to solder it just tug a bit and throw some tape over it, I guarantee you'll make it home with this as a temporary solution. Worked for the phone company for a while and have used it many times. I'm not suggesting to sail across the atlantic that way but if you need to put two wires together for a bit without real tools.... God bless Ma Bell.

 

[Don S/V ILLusion]

somebody should warn the astronauts that the space program doesn't follow ABYC standards.

 

[RAD]

Just came across some old knob and tube wiring from 1900's and this was a very common splice

 

[Jackdaw]

I always do this when I go into space, don't you?

 

[Bill Roosa]

It doesn't work on everything! Unless you have some sort of mechanical winder or you are the Hulk I'm thinking this is a splice for small wire diameters. I can't imagine using this on OOO wire let along stranded OOO.
MS
Do we know what the ABYC standard for splices is? I got the standard for the ends but I don't think I've ever seen one for splicing two wires together. Please don't tell me it is a crimp with heat shrink as that is no less "rigid and subject to breaking" than the WUPTS

 

[tommays]

I find it hard to believe that they use much if any solid wire on airplanes or space stuff

 

[Maine Sail]

I find it hard to believe that they use much if any solid wire on airplanes or space stuff

It is funny that when you put the word NASA in front of something that people automatically assume that is only for rockets or space ships. Those standards include ground operations in which NASA has thousands of miles of wire ...

Just like the Mil-Specs they are written to cover lots of operations...

 

[Maine Sail]

Do we know what the ABYC standard for splices is? I got the standard for the ends but I don't think I've ever seen one for splicing two wires together. Please don't tell me it is a crimp with heat shrink as that is no less "rigid and subject to breaking" than the WUPTS

It says solder shall not be the sole means of mechanical connection. When a standards interpretation was asked for they clarified that twisting or splicing of stranded wire does not count as a "mechanical" connection. Thus a soldered WU splice on stranded wire does not meet the standard..

 

[Bill Roosa]

so I gathered from your first post. Did they have a recommended sufficiently "mechanical connection"?

 

[Maine Sail]

so I gathered from your first post. Did they have a recommended sufficiently "mechanical connection"?

Usually crimps or pressure clamps, like Euro strips, where the screw does not directly impact the wire stranding.. Manufacturers approach the PTC all the time trying to get new methods on the standard. Most recently was for thermal welded wiring harnesses. They were turned down based on evidence...

We need to remember that solid copper is not used in boats. The WU was/is intended for use on solid wire not stranded. It has little strength in UL1426 finely stranded wire when compared to solid copper.

 

[kenn]

Yeah I learned that as the "Western Union' splice many moons ago... [rimshot] ...moons... NASA... <sigh>....:cry:

so I gathered from your first post. Did they have a recommended sufficiently "mechanical connection"?

A "running" splice is against most wiring codes, ABYC included. Obviously it's intolerable in new construction. For retrofits or modifications...would you tolerate an electrician putting a running splice in your house wiring if it wasn't enclosed in a code-compliant box, and made using approved wire nuts?

To get home, or as a last resort, yeah I'd consider doing a running splice on my own boat, but unless the soldering is immaculate and the connection is properly de-fluxed, waterproofed, secured and protected, I wouldn't consider it a permanent fix.

The ABYC spec is for approved crimped connectors (mainly terminal strip lugs, approved bullet connectors for circuits carrying less than 20 A). I don't think they approve of splices using those crimp-on wire-nuts.They also approve certain types of terminal strips that clamp onto the wire, as MS described.

Boat wiring often carries alot of current. I think the ABYC standard is reasonable here.