UK Sub main joining niceic advise Needed

[Viper22mike]

Joining niceic and doing a sub main to a garage off a tns earthing arrangement using 6mm Swa. The question is I have 25mm tails on 100a main fuse to a down rated dp isolator with a 63a fuse from there the swa. I'm filling in the eic for them to view do I put the 100a or 63a main fuse size in and 16mm main earth or 6mm for the circuit many thanks for the help

 

[timhoward]

"The supply is the supply" - still rings in my ears from my boss a long time ago....
In other words, the supply section near the beginning of the EIC always relates to the origin of the supply in every way.

See the bit in the distribution board section for where the board is not connected to the origin of the supply - that bit needs filling out.

Forgive me asking, but how have you run the cable? e.g. clipped direct, underground etc... (I'm just wondering about the cable rating.)

 

[Viper22mike]

"The supply is the supply" - still rings in my ears from my boss a long time ago....
In other words, the supply section near the beginning of the EIC always relates to the origin of the supply in every way.

See the bit in the distribution board section for where the board is not connected to the origin of the supply - that bit needs filling out.

Forgive me asking, but how have you run the cable? e.g. clipped direct, underground etc... (I'm just wondering about the cable rating.)

Clipped direct then goes down under the concrete 600mm down and warning tape it's underground for only a distance of 650mm and back up into the garage to a DB only using 26a max 1 light circuit 1 radial. And thank you for the reply

 

[Viper22mike]

"The supply is the supply" - still rings in my ears from my boss a long time ago....
In other words, the supply section near the beginning of the EIC always relates to the origin of the supply in every way.

See the bit in the distribution board section for where the board is not connected to the origin of the supply - that bit needs filling out.

Forgive me asking, but how have you run the cable? e.g. clipped direct, underground etc... (I'm just wondering about the cable rating.)

Any help would be greatly appreciated

 

[nicebutdim]

Clipped direct then goes down under the concrete 600mm down and warning tape it's underground for only a distance of 650mm and back up into the garage to a DB only using 26a max 1 light circuit 1 radial. And thank you for the reply

Working from memory here, but the assessor might not be impressed with that cable being protected by a 63A fuse.

 

[Viper22mike]

Working from memory here, but the assessor might not be impressed with that cable being protected by a 63A fuse.

OK I should downgrade the fuse

 

[timhoward]

Clipped direct then goes down under the concrete 600mm down and warning tape it's underground for only a distance of 650mm and back up into the garage to a DB only using 26a max 1 light circuit 1 radial. And thank you for the reply

Any help would be greatly appreciated

Look at table 4E4A, page 464 of big brown book.
Consider if the 63A fuse is the right choice for the protective device.

 

[nicebutdim]

OK I should downgrade the fuse

I'm an apprentice and working from memory, but fairly certain 63A protection wouldn't be acceptable. Better to check than take my word for this.

 

[Viper22mike]

OK I should downgrade the fuse

Working from memory here, but the assessor might not be impressed with that cable being protected by a 63A fuse.

I'm an apprentice and working from memory, but fairly certain 63A protection wouldn't be acceptable. Better to check than take my word for this.

Look at table 4E4A, page 464 of big brown book.
Consider if the 63A fuse is the right choice for the protective device.

Looking at the table from what I see 6mm clipped direct 62a and in the ground 53a is that what you have

 

[Viper22mike]

I'm an apprentice and working from memory, but fairly certain 63A protection wouldn't be acceptable. Better to check than take my word for this.

Looking at the table from what I see 6mm clipped direct 62a and in the ground 53a is that what you have

 

[nicebutdim]

Looking at the table from what I see 6mm clipped direct 62a and in the ground 53a is that what you have

Sounds about right if 2 core.

 

[timhoward]

Looking at the table from what I see 6mm clipped direct 62a and in the ground 53a is that what you have

Yes. So the cable can carry 53A at most onerous point. Do you see the issue with the 63A fuse? (reg 433.1.1)

Sounds about right for 2 core.

He's in the right column for a single-phase supply, even if he has a 3rd core as a CPC.

 

[Viper22mike]

Sounds about right if 2 core.

53 and 44 3 core maybe I should select a lower rated fuse

 

[westward10]

Don't want to sound negative here but if you are trying to join the NICEIC you should know rudimentary cable sizing.

 

[Viper22mike]

Sounds about right if 2 core.

95

Yes. So the cable can carry 53A at most onerous point. Do you see the issue with the 63A fuse? (reg 433.1.1)

He's in the right column for a single-phase supply, even if he has a 3rd core as a CPC.

I do have three cores one as cpc. I'll look for a lower fuse

 

[Viper22mike]

Don't want to sound negative here but if you are trying to join the NICEIC you should know rudimentary cable sizing.

I've done cable sizing before but have been told for ages what to put. I asked the chap I worked for before I said I was going to see he said stick 63a in if its the lowest in box.... Should of looked to check its my own fault its on me. When I said I wanted to join niceic and now he doesn't talk I'm on my own. I thank you for your help I'll look for a 40a fuse for it

 

[Viper22mike]

I've done cable sizing before but have been told for ages what to put. I asked the chap I worked for before I said I was going to see he said stick 63a in if its the lowest in box.... Should of looked to check its my own fault its on me. When I said I wanted to join niceic and now he doesn't talk I'm on my own. I thank you for your help I'll look for a 40a fuse for it

I've done cable sizing before but have been told for ages what to put. I asked the chap I worked for before I said I was going to see he said stick 63a in if its the lowest in box.... Should of looked to check its my own fault its on me. When I said I wanted to join niceic and now he doesn't talk I'm on my own. I thank you for your help I'll look for a 40a fuse for it

53 and 44 3 core maybe I should select a lower rated fuse

Thanks for your help it's very much appreciated guys

 

[timhoward]

I've done cable sizing before but have been told for ages what to put. I asked the chap I worked for before I said I was going to see he said stick 63a in if its the lowest in box.... Should of looked to check its my own fault its on me. When I said I wanted to join niceic and now he doesn't talk I'm on my own. I thank you for your help I'll look for a 40a fuse for it

Hang around here for a bit, keep reading the regs book, and in no time you'll be able to outsmart most of the people coming to assess you (but never be too clever, they like to think they are experts!)
Main thing at the beginning is to be able show you know what you are doing with testing.

 

[Viper22mike]

Hang around here for a bit, keep reading the regs book, and in no time you'll be able to outsmart most of the people coming to assess you (but never be too clever, they like to think they are experts!)
Main thing at the beginning is to be able show you know what you are doing with testing.

Thanks for the help and thanks for the advice it's very much appreciated

 

[davesparks]

Yes. So the cable can carry 53A at most onerous point.

53A would be the tabulated value, not necessarily what the cable can carry.

Rating factors need to be allied which can either increase or decrease the tabulated value.

 

[davesparks]

Looking at the table from what I see 6mm clipped direct 62a and in the ground 53a is that what you have

You can't just look at the table, you need to do the cable size calculation to establish what size cable you need for the chosen OCPD.