My brother and his family live in an older house. It's old enough to have metal pipes as electrical conduits, quite uncommon nowadays in The Netherlands.

He wants to rewire some parts, to move some switches, and to fix a hotel switch that doesn't work. He has no idea what wires were used; for all he knows there may still be some textile-wrapped wires in there.

I'm worried about the new electrical wires getting scraped when pulling them, having exposed wire which can come in contact with the conduit.

What can we do to prevent that? Is there any sheating we can apply? Should we use YMVK cable where possible?

Is there anything else we should know about metal conduit vs pvc?

Please note that this is in The Netherlands, where building codes may differ from the USA.

Replacing all metal conduit by pvc conduit is not an option, as they run in his ceilings as well, between the upper level floor and the lower level plaster on metal wire mesh ceilings with ornaments.

Note that metal conduits are unusual in The Netherlands, as the standard has been pvc for over half a century. My guess is that wires available in home improvement stores will be tailored towards that.

My understanding is that metal conduit is allowed in existing installations, but not for new ones. My brother doesn't want to replace the metal conduits per se, but any new instalments (for instance when relocating a switch) will have to be pvc.


1 Answer 1


Don't replace metal pipe with PVC "just because it's what everyone uses today". Metal pipe is superior in every way. And may also provide a valid earthing path.

You should not use cable in conduit. You should use individual wires which are rated for pulling through conduit. For instance, North America uses THHN, which has a nylon outer coating to make it slick for pulling. Surely any wires sold as individual wires will be made for this, because it will obviously be used in conduit!

All curves in your conduit should be broad turns. If you have sharp corners, there will be a removable cover to access the wires. You do not drag wires around corners - you remove the cover, pull to there, then pull the next segment.

  • 1
    May be a difference in codes between The Netherlands and the USA, but while existing metal conduits don't have to be replaced, they aren't allowed for new ones. Also, from what I found so far, cables seem to be recommended and possibly mandated for use in metal conduit.
    – SQB
    Jan 11, 2020 at 15:05
  • 2
    Also, I'm pretty sure that according to code, the conduit is not to be used as an earthing path.
    – SQB
    Jan 13, 2020 at 8:58
  • Interesting, the different values @SQB. In America, metal EMT conduit is considered deluxe, and residential wiring methods aren't allowed in commercial/industrial installations - only EMT or better. I've almost never seen ground wires in EMT. Cables aren't prohibited in conduit, but the rules are disfavorable (oval cables are treated as a round cable of the widest dimension, requiring large pipe). Jan 13, 2020 at 19:14
  • I must admit I know very little about industrial code, and that I'm not completely sure about residential, although the fact that home improvement stores only carry pvc, is an indication.
    – SQB
    Jan 14, 2020 at 5:20

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