I don't know how it compares with New Zealand, but this is one thing which is a particularly noticable difference between American and British practice even in a residential setting.
In the U.K. we're far more likely to have exhaust fans, garbage disposals, pumps, and similar devices hardwired to a wall outlet where they'd likely be plug-and-cord connected in the States (not to mention heavier stuff like electric ranges).
That's a good point to consider. PVC is the norm for all hard-wired cords here now unless conditions demand something else. Butyl rubber is still used in this way when connecting to immersion heater elements, storage heaters, and similar appliances though.
The NEC allows the use of hardwired rubber cord for some installations but is pretty tight about it.
Here is my guess why, here in the US flexible cords are made of rubber which tends to dry rot.
When I have worked with flexible cords from other countries I find them to often be of better quality, not made primarily of rubber etc.
I would be all for a move away from the US type rubber cords to European type flexible cords.
Bob, Is the use of PVC flex not that prevalent in the US? Rubber has certain advantages when used in Industry, in that it is resistant to attack from things like gasoline, oils and the like. PVC however, being polymer-based should not be exposed to these sorts of things. PVC also has the down-fall of being awkward at low temperatures, it is hard to work correctly when the temperature is low. I worked on a large PVC cable some years back at the hieght of winter and it snapped like a fresh carrot,luckily the 400V supply had already been turned off to it.
Mike, I can't pretend to speak for the entire trade, but it seems to me that PVC conduit is mainly used for underground runs. A secondary use is where exposed to corrosive chemicals, such as pool rooms. Finally, the PoCo seems to like it for their wires, whether for an underground run, or when coming down their poles.
In that case, I believe that our most common type of wire insulation (THHN) is an insulating PVC layer covered by a nylon protective sheath.
That said, from my work around plastics, I must add that PVC is by far the most added to, treated, blended plastic around. Saying something is made of 'pvc' is a lot like saying it has steel in it - there's an almost infinite variety of products, ranging from the junk to the jewel.
I think Trumpy was mostly talking about cords which do seem mostly rubber isolated in US commercial setups, unlike residential appliance cords. Europe tends to use PVC or even neoprene. Rubber cords are only used (as Trumpy mentioned) where the cords are prone to be exposed to oil, gasoline,...
Yeah Ragnar, That is precisely what I was mumbling about. I did an electrical inspection in a new service station/workshop, just before I left the PoCo, all of their leads were made of PVC, I told them they should be using rubber cords, that was a surprise to them.