Fungus (mold) on cable sheath

[Sam_Butler]

Oh yes, this is my first post. Be as kind as you wish ;-)

I'm maintaining a building and found a white fungus on the outer sheath of tails within a metal enclosure and a 3-phase switchfuse. I'm wondering if it's something to be concerned about; I presume it's a result of humidity since the cupboard had been used to store cleaning materials (probably including wet cloths or mops) and this is in a basement that has flooded due to leaks and a burst main water pipe. It's been through the wars!

To put it into perspective I've drawn the installation, with the lid removed off the enclosure below the meter, which contains the DNO cut-out fuses and neutral block. And I assure you, it doesn't look anywhere near as neat as this:


And here is the fungus inside the large switchfuse in the bottom-left of the diagram:


And here within the enclosure below the meter:


So, wise ones, is this something I should be concerned about, aside from the obvious concerns over health from fungus spores?

If you look back at the diagram, the incomer is MI and those red-sheathed tails that run to the 3P 60A switchfuse run through a short length of steel conduit. Inside the enclosure, the fungus almost seems to grow out of (or into) the entry point of the conduit. It has inspection elbows but I haven't opened it up so as not to make any airborne spores worse if the thing is just a big furry mess inside, but the conduit is clearly corroded showing signs of uninhibited moisture ingress.

It's certainly not something I see every day, so I'd appreciate some feedback. Cheers!

 

[malcolmsanford]

Well first get a decent mask and gloves and clean the fungus/mould/whatever off the conductors and have a good look at the insulation. Personally I would arrange a shutdown for a couple of hours and do an IR on the tails, might be a little ovie there for you.

If everything checks out ok then reg 522.9.1 does give some advice but note 2 and regular cleaning and checking sounds the best way forward.

Be hard to seal the system off. Give the building management the old health and safety talk on electrical cupboards not being used as store rooms and you advise them to have all that stuff removed. Also The DNO should have a duty of care to move the header if the area is prone to flooding.

 

[Marvo]

Maybe some forced ventilation into the room would help keep the humidity down and prevent regrowth after you've cleaned it up. A small centrif fan supplying fresh air at a rate of maybe four times the volume of the room per hour should be sensible.

Congrats on your first post by the way, this one is only my second or third