Cable Splicing

If this product was ordered to a specification that requires "spliceless" cabling, then it's not to spec.

Supplier should have asked for a deviation, after demonstrating that the splice can meet all the other requirements.

Otherwise, why bother to specify anything?

I'd make them sweat for awhile, then tell them that, this one time, you'll accept this non-compliant material. Or, just make them replace it.

Well the problem is the specification is our end customer's spec, not ours. Therefore the cable company is putting us in violation of our customer's spec. We just purchase these cables assuming no splices - that is why I asked if it was an accepted cabling industry practice. If so, we need to start specifying no splices to our suppliers.

I definitely expect to get a replacement - and threaten to start using a competitor's product.

I can't speak to today's accepted cabling practices regarding splices.

This sounds like a self-inflicted problem. If you are knowingly supplying cables that do not meet the customer's specification, you should be asking for a deviation from their specification.

Ok, so I spent over 20 years working on electronics for various federal spacecraft programs.

The quality requirements of your industry may allow such deviations, that I don't know.

If that is the specifications from your customer you made a basic mistake by not flowing the specifications down to your supplier. If the cable is not acceptable with splices then reject it and negotiate them replacing it with one that is. Normally splicing is not acceptable in a manufactured shielded cable.

"If this is an accepted industry practice". Of course not. The Manufacturer must replace the defected length [may be, he could replace entire delivery!].

The fault it is not intentionally done [I hope!]. When one length of conductor get its end the extruder people has to connect [roughly] with the next length in order to continue the extrusion. But it has to be marked and to be cut .The usually test sometime cannot detect the defect.

Seems intentional to me - just one conductor of 5 was spliced. I would expect all 5 would reach the "end" at very near the same length and there would be 5 splices very near to each other, not just one by itself. We examined about 1 meter of length and there was only the 4th conductor spliced.

I've run a fair amount of cable, and this is first I've heard of this practice. You are fortunate you found it before installation. Imagine if the customer, or his agent had run a TDR check. I would notify the vendor immediately, and then make purchase a TDR or equivalent to check this in the future. With today's high price of copper, this practice may be more common than you think. If the customer "specced" splice free cable, this means he was aware of this practice. I'm really surprised that no one on this site has mentioned this previously

in all my years of rigging and splicing cables, i've never see or heard or this shoddy practictice. i think Lyn has the aisc manuel. cable slicing is included in the manuel.

A final note on this to all - thank you for your responses.

The manufacturer is now starting an investigation in to this and has requested a manufacture lot ID number from the cable. Therefore I have to assume this is not a standard practice by this manufacturer. (I bet they just do final assembly of the completed cable with connectors and out-source the components and cabling - some other manufacturer is about to have a very bad day as I have sent pictures of it to the local distributor to forward)

Final, final note - thanks again for your help. The cable manufacturer admits they outsource the bulk cable used to make their product. The out sourced manufacturer was directed to never splice. So, my question has been answered - splicing apparently does happen, but this manufacturer does not want that. I'll never know for sure, but do you want to bet the outsource manufacturer is in China? This manufacturers prices dropped about 30% a few years ago - probable start of outsourcing.

From MIL-DTL-27500: (underline is my emphasis)

CABLE, POWER, ELECTRICAL AND CABLE SPECIAL PURPOSE, ELECTRICAL SHIELDED AND UNSHIELDED, GENERAL SPECIFICATION FOR

3.5 Cable lay-up. The required number of wires for multiconductor construction determined by the cable designation shall be cabled with a left-hand lay. The lay of the individual wires shall be not less than 6 nor more than 16 times the outside maximum diameter of the unshielded, unjacketed cable as calculated in 4.4. The basic wire shall not be spliced. When cables are cut, wires shall not splay more than twice the diameter of the cable.

3.7.4 Shield splices. If splices are used in the shield, they shall not affect the geometry of the finished cable. No more than one carrier may be spliced at any one point in the shield.

You can however have splices in the strands of your basic wire. This is from MIL-DTL-29606:

3.4 Splices. For conductor types TCC, SCC, SCC1, NCC, NHC, SCA, SCA1, NCA, NHA, SCU and NCU, splices in individual strands or members shall be butt brazed, or a similar process shall be used that does not damage the outer coating integrity. There shall not be more than one strand-splice in any two lay lengths of a stranded concentric-lay conductor or in any two lay lengths of any member in a rope-lay conductor, except that not more than one splice of the entire member shall be permitted in any two lay lengths of rope-lay conductor. Splices in members of a rope-lay construction shall be finished such that the conductor diameter is not increased at the point of joining. In no case shall the whole conductor be spliced at any one point.

Clear as day, right?

Simple really, if YOUR customer states 'non-spliced' as a spec.. then no more to be said or debated.. that is what you supply.

Standards or common industrial practices really have nothing to with it. Your company is to deliver to your customer what they have asked for, the cable company supply what their customer.. YOU, asked for.

At this moment in time your relationship is good with your client... I doubt if that will be the case if you send this non-spec cable you've received to them and THEY check it! Your supplier dropped the ball, which in turn will screw up this order or worse still, future orders.

Send it back as 'not to spec'.. end of!

In future.. audit your suppliers! Making sure that at least one employee can read a spec sheet!

Most likely the cable manufacture spliced the cable so they did not need to re-thread the manufacturing machine that twists, braids and cases the cable. The cable manufacture then sub-divide and package from huge manufacturing spools to smaller spools for distribution. I do not believe the company that created the individual cables was even aware of this as they just cut the wire to length and add connectors. Should it happen in the industry, no but does it happen, probably as you can testify to.

The base answer is IT IS NOT AN ACCEPTABLE INDUSTRY standard.

You need to review what the specification for the purchase indicates.

Next you need to document the splice found, location, photos, etc.

Next go to the manufacturer and request either a free replacement or return on the cost of the cable plus the removal and re installation costs.

Finally let the client know that this is unacceptable and request a deviation in case it impacts the job schedule.

Also document indicating that it was you who found it, even if by accident, so that the responsibility of the check out, QA/QC checks and acceptance, etc., is shown as by others, its a good idea to cover all the bases.

Since the cable can be used without the conductor which was damaged, the cost reimbursement will be a nice thing for the project.

But be warned it this happened with once cable where is it indicated it may not have happened with other cables, so check them.