flexible duct for armoured cable - AFFL!?

[marmic]

Morning all,

 

Not the correct department to post in but something up with website not enabling some to be selected!

 

As ever because we are doing something a bit different to 'normal' have another conundrum so todays question requiring opinions/answers/thoughts etc please - don't be shy:

 

We have flexible ducts into plant room entering through floor for incoming electric main, STP, RWH, PV, external lights/power, data.  (Only holes in walls are for ASHP/MVHR - must avoid any more for various reasons including passivhaus high performance). Suddenly feeling twitchy as some of these ducts finish outside above floor level - thinking possible water ingress over time, or am I overthinking this? We also have ducts for water (RWH already in and future main) but these terminate underground at low level so they are fine

 

• The one directly next to house currently out of ground I'm currently thinking cut back a little to slightly above ground level and seal with foam + silicone once cables in. Is this correct?
• for data cables the duct end will be higher but will terminate in adjacent outbuilding which is above ground built off piers - so not concerned there about water through end of duct, but will still seal up open end to prevent insects/rodents.  But what about where it's above ground for a short distance and where it enters ground and in ground - is there a risk of water entering over time if chewed by rodents for example? Albeit will they actually chew it as no food source there - thinking probably not as we are currently using same sort of flexible pipe for a temporary grey water drain at ground level and not been touched.
• for the incoming main (which is my main concern):  Large armoured cable running from green box (with meter) about 60m away. This will just be laid on ground parallel with and tight to hedgerow (covered in brush and stable mucking out to prevent it being seen and theft) and will gradually sink. Where it turns away from hedge to house it will then enter duct (higher than floor level) which then goes underground for the last bit of it's journey. Do I carry on as planned and seal up the end, or do I need to dig a hole where duct currently disappears into ground and cut it underground below floor level and seal it there?
• STP/RWH lower so no concerns there.

 

I need to decide what to do ready for Wednesday - day off employed work to get ready for second fix electrics commencing next week, which includes pulling cables........

 

many thanks...........M

[marmic]

9 minutes ago, marmic said:

- day off employed work to get ready for second fix electrics commencing next week, which includes pulling cables........

 

many thanks...........M

ps -  my work wednesday is getting ducts ready etc -  electrician pulling the cables (design/supply/install/certify)

[marmic]

no opinions??  a rare event  !! .................. 😀

[FuerteStu]

My opinion. 

 

Ducts will always end up full of water. Nearly every single duct I've pulled through has ended up with a soaking wet cable/cobra/rope coming out the end.

 

It's why you need cables rated for ducts (for data and coax etc) and to make sure the cables aren't dragged across sharp things in the way in. 

 

As for mains cable resting on the surface and covered over with a rotting mess.. Never in a million years. Do not do this.