Unable to run cables at a sufficient depth outside

[Basset]

I’ve installed electric gates at a property.

One of the issues I’ve had is I was unable to bury the cables at a sufficient depth as this would have weakened the driveway. So, I laid an earthed SWA cable around the edge of the driveway and encased it in 5cm of concreate, marker tape over that and then the driveway on top of that. It’s also protected by an RCD.

Cost me a lot of money, but the customer refuses to pay me as they were told that the cables should be have been buried 550cm. I’ve tried to explain how I have provided equivalent protection against mechanical damage, but they are not budging.

I’d just like to get your thoughts on this and any advise

Many thanks

James

 

[snowhead]

What does "weakened the driveway mean"?

Did you discuss the depth issue with the customer when you discovered it?

 

[pc1966]

I guess you mean 550mm? 5.5m is quite a dig!

In any case there is no specific requirement on depth for private land, only that it has to be adequately safe from any likely activities. Even for the electricity supply utilities like SSE putting in large non-RCD protected cables the depth depends on the land use so 45cm for footpath, 60cm for public road (carriageway), and 1m for arable land (i.e. ploughed field).

Given it is in concrete and so not going to be accidentally hit by a gardening spade, etc, I would say it is suitably protected.

Was anything specified in any contract or quote?

 

[brianmoooore]

Burying the cable to a sufficient depth with no other protection is just one way of protecting it from damage, but not the only way. In that respect, your customer is wrong.
You have adequately protected the cable for now, but concrete this thin will almost certainly crack in time, and if the cable is enclosed in it, this will produce shear forces on the cable at the cracks.
What you should have done was to bury the cable as deep as possible, surrounded by 'graded material' (earth with stones removed or sand), then laid pre cast concrete slabs over it, made for the purpose.

 

[littlespark]

Our regs state “deep enough as to not get damaged” so under a pathway doesn’t have to be as deep as a ploughed field.

however it may be that this 550mm depth is dictated to in the electric gates installation manual, in which case, they could be a little tricky if anything goes wrong.

 

[Julie.]

Our regs state “deep enough as to not get damaged” so under a pathway doesn’t have to be as deep as a ploughed field.

however it may be that this 550mm depth is dictated to in the electric gates installation manual, in which case, they could be a little tricky if anything goes wrong.

Agree

There is no defined depth in the regulations.

Only anything in the contract or supporting documents from that

Swa doesn't even need to be buried, from a wiring regs point of view, it could just be laid on the surface as long as it is suitably restrained.

 

[richy3333]

Irrespective of cable protection types it does sound as though you haven't agreed this cost with your client? If thats the case then I'm not surprised they won't pay.

 

[Julie.]

Irrespective of cable protection types it does sound as though you haven't agreed this cost with your client? If thats the case then I'm not surprised they won't pay.

I take it the op is saying that they are not paying for the work overall, not any additional cost the op incurred.

But I could be wrong.

 

[Deleted account]

was the routing and depth agreed I the quote.

If so at the point where the works altered from the original quoted for the client should have been informed.

if not your client is wrong. What you have done is absolutely acceptable .

 

[stevethesparks]

Hence, I do not do any digging or replacing of lawns, roadway's or anything else.

 

[Basset]

I take it the op is saying that they are not paying for the work overall, not any additional cost the op incurred.

But I could be wrong.

The job was for a driveway company. I was told they didn’t want to disturb the existing driveway as they were laying straight over the top. I was asked what could done and agreed that laying the cable in a small channel with a sting mix of concrete over it and then a new driveway would be adequate protection. No one is going to use a shovel to turn over earth etc.

 

[Basset]

What does "weakened the driveway mean"?

Did you discuss the depth issue with the customer when you discovered it?

I discussed this with both the customer and driveway company. I laid the cable and installed the electric gates and intercom. Job done. This when the customer had a fall out with the driveway company and said the cable was not deep enough.

 

[Basset]

I guess you mean 550mm? 5.5m is quite a dig!

In any case there is no specific requirement on depth for private land, only that it has to be adequately safe from any likely activities. Even for the electricity supply utilities like SSE putting in large non-RCD protected cables the depth depends on the land use so 45cm for footpath, 60cm for public road (carriageway), and 1m for arable land (i.e. ploughed field).

Given it is in concrete and so not going to be accidentally hit by a gardening spade, etc, I would say it is suitably protected.

Was anything specified in any contract or quote?

Thanks for your reply. Unfortunately There was no contract drawn up

 

[Basset]

Burying the cable to a sufficient depth with no other protection is just one way of protecting it from damage, but not the only way. In that respect, your customer is wrong.
You have adequately protected the cable for now, but concrete this thin will almost certainly crack in time, and if the cable is enclosed in it, this will produce shear forces on the cable at the cracks.
What you should have done was to bury the cable as deep as possible, surrounded by 'graded material' (earth with stones removed or sand), then laid pre cast concrete slabs over it, made for the purpose.

That I guess would have been the perfect solution, but I chose the concrete method thinking it would protect it.

 

[Basset]

Our regs state “deep enough as to not get damaged” so under a pathway doesn’t have to be as deep as a ploughed field.

however it may be that this 550mm depth is dictated to in the electric gates installation manual, in which case, they could be a little tricky if anything goes wrong.

There was no documentation saying the cable must be buried 550mm in the gate installation manual.