Getting a mains cable down underground ducting

I am hoping there is a trick I'm missing here, but I suspect the answer wil= l start with "dig it up". Please don't fail me ;-)

Doing our garden, I have buried seven metres of ducting to run cable for a = water feature. It is rubbery mains cable, and I need to get it through the = ducting. The ducting is 19mm internally, and has a slightly "grippy" feelin= g to its inside, as does the cable.

Now, I was hoping I could pull the cable down the ducting. No such luck - i= t gets stuck at the tiniest of curves. I have tried sucking it down with a = vacuum, which has been no more successful.

There are no tight bends, just gentle curves. String can be sucked down wit= h a vacuum cleaner without any problems. So, I'm guessing the issue is fric= tion - rubbery plastic against rubbery plastic.

The big question is, is there a lubricant I can add to the cable to get it = around the curves? I could dig the trunking up, but if the water feature (a= small, sealed pump) ever failed, then I would need to get a new cable down= .

I don't want to leap in trying greases, because if I used the wrong one, an= d it made matters worse, I may be stuck with trunking I can't use at all. T= he pump cable needs to thread through the base of the water feature first, = so the cable could not have been put in before the trunking was installed.

Thanks,

-- Jason

Reply to
Jason Judge
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Reply to
Andy Burns

Talcum powder.

Reply to
Dave Plowman (News)

then, I didn't know what I was looking for :-)

Reply to
Jason Judge

Scrap everything you have done, because its illeagla and will void your insurance and buy some armored underground mains cable.

Reply to
The Natural Philosopher

It's not permanently wired in - the cable comes out to labelled standard pl= ug, used with its own RCD. There are no cable joins outside, which is one t= hing I wanted to avoid (the tiny pump comes sealed, with a 10m mains cable)= . I've laid bricks over the conduit, to protect it from above. The conduit = runs for five metres under a small lawn, which will soon be paved anyway.

Is this still illegal, even if not a part of the house wiring?

-- Jason

Reply to
Jason Judge

Don't know why I didn't think of that one. As a kid, flexible mains cable always seemed to contain white powder to help it bend. Haven't seen that for a while, so I guess they use something else, or different types of plastic.

Reply to
Jason Judge

En el artículo , Jason Judge escribió:

presumably you're using the string to pull the cable through.

I used something very similar to this successfully for a similar job a couple of years ago, albeit over about 50m of ducting.

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distance you need to pull through is only short, though. Try washing-up liquid, wiping plenty onto the cable with one hand as it passes into the end of the ducting.

I think you're right to consider that, especially with rubbery insulation which may be damaged by oils.

Reply to
Mike Tomlinson

be helpful on shorter runs are the silicone sprays, also good on pushfit waste fittings, gutter couplings, plastic curtain tracks...

Reply to
newshound

or, of course, a 19 mm diameter ferret...

Reply to
newshound

Yes, I tried, but it just snapped. Once the cable gets stuck, it is pretty = firmly stuck.

I thought, "Seven metres? That's not going to be a problem!". Ha to me!

I may just get a bottle of this or any earlier one recommended, and it will= be useful for other jobs.

I doubt it is rubber, but it just that kind of feeling. =20 Thanks.

Reply to
Jason Judge

Sprays like furniture polish? I used that on a wooden curtain rail I put up fifteen years ago, and have only had to top that up once in all that time.

Reply to
Jason Judge

Any reason why you can't use the string to pull it through? Have I missed something?

Reply to
Peter Johnson

Doing our garden, I have buried seven metres of ducting to run cable for a water feature. It is rubbery mains cable, and I need to get it through the ducting. The ducting is 19mm internally, and has a slightly "grippy" feeling to its inside, as does the cable.

Now, I was hoping I could pull the cable down the ducting. No such luck - it gets stuck at the tiniest of curves. I have tried sucking it down with a vacuum, which has been no more successful.

There are no tight bends, just gentle curves. String can be sucked down with a vacuum cleaner without any problems. So, I'm guessing the issue is friction - rubbery plastic against rubbery plastic.

The big question is, is there a lubricant I can add to the cable to get it around the curves? I could dig the trunking up, but if the water feature (a small, sealed pump) ever failed, then I would need to get a new cable down.

I don't want to leap in trying greases, because if I used the wrong one, and it made matters worse, I may be stuck with trunking I can't use at all. The pump cable needs to thread through the base of the water feature first, so the cable could not have been put in before the trunking was installed.

*************************************************************************** As suggested earlier, talcum powder works wonders. Also, if you pull string through, why not use that to pull some strong nylon cord through before using this to pull the cable. This is unlikely to snap with a strong tug.

Cheers

Dave R

Reply to
David WE Roberts

Talcum powder?

Reply to
Tony Bryer

start with "dig it up". Please don't fail me ;-)

water feature. It is rubbery mains cable, and I need to get it through the ducting. The ducting is 19mm internally, and has a slightly "grippy" feeling to its inside, as does the cable.

gets stuck at the tiniest of curves. I have tried sucking it down with a vacuum, which has been no more successful.

vacuum cleaner without any problems. So, I'm guessing the issue is friction - rubbery plastic against rubbery plastic.

around the curves? I could dig the trunking up, but if the water feature (a small, sealed pump) ever failed, then I would need to get a new cable down.

it made matters worse, I may be stuck with trunking I can't use at all. The pump cable needs to thread through the base of the water feature first, so the cable could not have been put in before the trunking was installed.

KY Jelly? According to Wikipedia "it does not react with latex condoms or silicone rubber-based sex toys" so should be OK with the rubber conduit and much more resilient PVC mains cable.

And you can use what's left over in the bedroom.

Reply to
Reentrant

As I said, this doesn't sound like metal ducting, and anything else is not legitimate.

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some armoured cable in.

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Reply to
The Natural Philosopher

Yes, Yellow 77 is the common one:

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you could also run a different cable through the duct, then use a waterproof cable joint to connect duct cable to rubbery cable nearer the pond.

Reply to
John Rumm

I have one of these which works very well in these circumstances:

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Reply to
Andrew Mawson

Seems like a rather bold claim. As has been discussed many times in the past, DIY under part P is not illegal, it simply makes some jobs notifiable.

Generally speaking, using pre assembled "kits" for outside power fall into the non notifiable category. The exception to this might be when using them to provide a permanent installation of "fixed" equipment. A standalone submersible pump would arguably not count as fixed.

Reply to
John Rumm

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