Insulated SWA Gland

[rolyberkin]

Has anyone used a plastic stuffing gland to insulate an swa cable entering a consumer unit on a TT installation, I know there are specific insulating glands but just trying to think of any reasons why a suitably sized plastic gland would not be appropriate?

I want to provide a separate earth on an out building some way from the supply point.

 

[Bobster]

What do you mean by insulating?

Why are you wanting to insulate it?

 

[rolyberkin]

What do you mean by insulating?

Why are you wanting to insulate it?

The supply is swa from a RCBO fed temp building supply and the workshop is about 60m away from the supply, I have a small RCD 3 way board and there would be a discrimination issue if I left the both ends of the swa connected . I could either fit a main switch to the small CU and use the rcbo for fault protection but due to the distance between the two would prefer to insulate at the small consumer unit, supply a separate earth rod and use the RCD for fault protection. Hope this makes sense, I have looked at CMP products insulated cable glands but could a plastic gland achieve the same result?

 

[hightower]

Would a plastic compression gland be suitable for use on SWA? I'm not sure it would. How about taking the SWA to a plastic box and then PVC tails coming out to the consumer unit? (Sorry, I know it doesn't help with using a compression gland question exactly)

 

[rolyberkin]

Would a plastic compression gland be suitable for use on SWA? I'm not sure it would. How about taking the SWA to a plastic box and then PVC tails coming out to the consumer unit? (Sorry, I know it doesn't help with using a compression gland question exactly)

Did mull over that but think the insulated gland direct into the CU would look a lot neater than adding a box, I will probably go with the CMP gland but thought I would ask the question.

 

[hightower]

Can you link to the gland? Not seen anything like it is all

 

[rolyberkin]

http://cmp-products.com/installatio...n_Fitting_Instructions_FI418_Issue_1_0211.pdf

Just got a quote and one company have come back to me with £24.00 +VAT for a 20mm and £33.00 +VAT for a 25mm.

May have to rethink!

 

[Bobster]

In answer, no a compression gland is not suitable for SWA.

Install a correct SWA gland into something insulated.

 

[Bobster]

The supply is swa from a RCBO fed temp building supply and the workshop is about 60m away from the supply, I have a small RCD 3 way board and there would be a discrimination issue if I left the both ends of the swa connected . I could either fit a main switch to the small CU and use the rcbo for fault protection but due to the distance between the two would prefer to insulate at the small consumer unit, supply a separate earth rod and use the RCD for fault protection. Hope this makes sense, I have looked at CMP products insulated cable glands but could a plastic gland achieve the same result?

What??

 

[rolyberkin]

What??

I want the RCD/MCB's to deal with any fault condition at the workshop and the RCBO to protect the cable.

 

[Bobster]

I want the RCD/MCB's to deal with any fault condition at the workshop and the RCBO to protect the cable.

Ok so you're a trainee, so being nice here.

Please think why insulating one end of the SWA will not offer any discrimination between the RCD's

 

[rolyberkin]

Ok so you're a trainee, so being nice here.

Please think why insulating one end of the SWA will not offer any discrimination between the RCD's

Yep having a brain storm, wouldn't make any difference, would need a time delay RCD at supply end. Caught up in considering line to cpc faults.

I think in my defence I was also considering provision of eventual Earth to house supply and whether this needs to be isolated and then supply a separate TT Earth at workshop end or whether to export earth.

 

[telectrix]

why do you want to protect a SWA with a RCBO?

 

[Bobster]

Yep having a brain storm, wouldn't make any difference, would need a time delay RCD at supply end. Caught up in considering line to cpc faults.

Why do you need an RCD at all?

I think in my defence I was also considering provision of eventual Earth to house supply and whether this needs to be isolated and then supply a separate TT Earth at workshop end or whether to export earth.

Is the house TT? You're not exporting an earth.

If the supply in the house is temporary, just bang a rod in at the workshop as well.

Do you not have somebody supervising you on this work? What is your boss's thoughts.

​Comments above

 

[rolyberkin]

The temp supply put in to the site is a rcbo board (I didn't put this in it was already there). I have taken swa from the temp board to the workshop/summer house using an rcbo. The swa will in time eventually be connected to the permanent supply in the house (when built), so in short just using what is there to supply lights and power to a summer house which my friend is using as a site office of sorts. I have a put a small consumer unit with an rcd/mcb in the summer house on testing it trips the rcbo which is some way from the summer house. All tests are okay, it just more of a nuisance walk than anything. There is no upfront rcd on the building supply just an rcbo board hence why I used a rcbo to feed the swa.

 

[telectrix]

change the RCBO for a MCB. also you need to determine whether the RCBO is tripping on earth leakage or overload.

 

[rolyberkin]

​Comments above

As per previous reply to Telectrix

Is a temp building supply which is TT, I have already put in a rod at the workshop also, the eventual supply to house when built will be TN-C so the consideration of exporting earth or continuing with a separate TT was at some point in the future. I am not doing the house install so the electrician undertaking will do what they want. Have no supervisor just doing this for a friend as a favour and a bit of experience.

 

[telectrix]

OK, so gland the SWA and connect the earthing at both ends. you'll then have a TT system with rods at the house and at the outbuilding. when the house is done, the electricians doing it can then decide on whether or hot to extend the equipotential zone or divorce the outbuilding.