Anyone have experience working with lead-sheathed wiring? The streetlights in my area (built 1939-1940) are fed by the original lead-covered wire in UG steel conduit.
It's low-voltage (240v) lighting.
In most areas the old stuff is holding up fine, but there are a couple of spots with recurrent problems. The City wants to replace all the conduit and wire with new. Cost for the rewiring is expected to run $675k.
So, I have a few questions:
1. What's the construction of the wire? I'm assuming copper conductor with rubber insulation and lead sheathing; would anything else have been used around 1940?
2. How long can such wiring be expected to serve reliably? I've heard of medium-voltage UG feeders sheathed with lead that are working fine after over 100 years.
3. Is this kind of wire prone to becoming stuck in the conduit? If so, do you have any info on the effectiveness of chemicals used to free wire in conduit (I know Coke can be used to good effect, if it's dried soap-based lube causing the problem). Any experience with a situation like this?
4. Any experience megging out this kind of underground wiring? What sort of resistence values indicate good wiring? I know that if it gets to that point, it'd be a question of using a meg-ohm meter to find the weakest links; but if anyone has experience with this, it'd be great to hear it.
I'm an electrical contractor and volunteer consultant just looking into options; the City staff seem pretty determined to tear out the old, even though the maintenance logs don't show widespread or frequent problems. And I'd rather not see public money spent unless it's necessary.
Thanks in advance--
