PVC Insulated Copper Wire Tensile Strength

http://en.wikipedia.org/wiki/Tensile_strength

The tensile strength of copper is what it is. Selection is not an applicable concept.

Not sure about the "selecting value"

As an educated guess the tensile strength will not be much more than the copper strands provide by themself.

But I am sure the conductor would have better not to see too much stress.

Select something else to take the stress on your conductor.

This would explain the purpose of the question from OP.

GA

...and if a proprietary lube is not available, try talcum powder instead.

The tensile strenght of copper wires is 200-250 N/mm², so you can't select it, it will be determined by the wire caliber that you'll run, which in turn will be determined by the load calculations, which in turn will be made by a qualified electrician.

Regards

I have heard about class 2 and class 5 conductors,but didn't get sufficient information on net.

You can access a certain imprecise amount of 'selection', in the 'decreased' direction by repeatedly bending the copper back and forth in the same place, making the wire, harder, more brittle, and if done enough, with reduced tensile strength.

Yes, fatigue; but I think the OP is more interested in the maximum tensile strenghts (per wire caliber).

...or, maybe, minimum tensile strength (per wire caliber)...?

It's a pointless question.

The fact is the PVC insulation will rip off the wire due to what ever friction is causing the conductor to need to be pulled on that hard long before the copper conductor breaks rendering the electrical circuit useless.

That and any straight line pull long enough to produce enough drag friction of the wire in a conduit will far exceed the circuits working amp capacity rating for said total lengths of the conductors in the circuit.

The point is if the total length f the circuit is that long you are way past the working limits of the conductors or if the conduit path has that many bends or too tight of bends (90 degree elbows opposed to swept radius fittings and joints) whomever designed and routed it didn't know what they were doing and a number of junction boxes or openings need to be placed in the conduit to allow for much shorter pulls to be done.

This information can be found in the cable manufacturer's literature and the appropriate electrical standards related to your specific country and application.

Proper pulling technique should minimise any chance of breakage during installation, regardless of the cable, and this should have been part of your training if your are a qualified electrical installer. I am not going to go into lube, bundling techniques, etc here.

Additional information can be found on the internet regarding cable pulling practices if you want some additional help, but the cable manufacturers website and standards are a good place to start if you just want an idea of what a particular cable can safely take before guide wiring, bundling (or similar) has to be used to alleviate the strain on the cables being installed.

_{Jack - I can pull my cable with the best of them, and we even make and sell our own cable lube!}

As many others have said the tensile strength is not the issue. The correct conduit size, appropriate lubrication & the procedures while pulling the cables through the conduit is all that is needed to prevent the conductors from breaking when pulling through conduits.

If the conductors are breaking while you are pulling them through the conduit then I would review your choices in those areas

If you search CR4 there is a thread in the last few months that someone posted about pulling cables through conduits & they asked for everyones suggestions of the best ways to do it. There was many excellent ideas on the topic