V
vader2015
Hey guys, i have started to do some inspecting and testing, i am finding it very interesting although the certification part is a little confusing lol. To help me i have been out and bought GN3 plus the NICEIC guide to inspecting, testing and certification, but there are some parts i am still a little unsure off so i have got a few questions if you don't mind helping me with, please bare with with me this might be a long read lol.
The installation in question is on a domestic TNS supply. The installation is in a detached garage, which incorporates the supply cable, consumer unit, 16A radial circuit, and 6A light circuit. The supply to the consumer unit is run in 6mm SWA externally and 6mm T&E (plus 6mm single for earth) internally. The 6mm supply cable is protected by a 40A switch fuse, fed with 16mm tails from henrys blocks.
I have got a few questions about filling out the EIC.
1. On page 2 of the EIC under the section SUPPLY CHARACTERISTICS, under sub section Characteristics of primary supply overcorrect protectective devices On the main cut out fuse, there is no clear markings of BS EN number, so i phoned western power to enquire. When i eventually got hold of someone who could supposedly answer my questions, they told me it should be BS 88 part 2, with 16KA breaking capacity (and the Ze was 0.8 ohms for the Ze enquiry test). Its the "should be" part that I'm unsure of, do i need to keep ringing them to get a more definitive answer? Or should i just put down what he said? I was also under the impression that all domestic cut outs were supposed to be BS 1361's?
2. Under the section PARTICULARS OF INSTALLATION AT THE ORIGIN, where you have 4 boxes for:
Measured Ze, Maximum demand, Number of smoke alarms, Protection measure(s) for fault protection.
What do you put in the box entitled Protection measure(s) for fault protection? Is it switch fuse? Or is it RCD/RCCB?RCBO? Or is it EEBADS? Or all of them?
3. Again under the section PARTICULARS OF INSTALLATION AT THE ORIGIN, where you have the sub section Main switch/Switch-Fuse/Circuit Breaker/RCD do i fill out the details for the 40A switch fuse, and not the consumer unit RCD?
i.e BSEN 60947-3, 2 poles, 230v, 40A etc
4.Under the section SCHEDULE OF ITEMS INSPECTED, under sub section 6.0 OTHER METHODS OF PROTECTION 6.1 Basic and fault protection, what do i put for the boxes titled:
a) SELV LOCATION
b) PELV LOCATION
c) Double insulated/Reinforced insulation
d) Electrical seperation for one item of equipment
For a) SELV, do i just tick the box? and what do i put in the location box, it is just garage?
For b) PELV do i just put N/A
For c) Double insulated/Reinforced insulation do i tick the box due to the SWA cable? and in location box put clipped direct/underground?
For d) Electrical seperation for one item of equipment do i just put N/A?
5. On page 4 of the EIC, should i put down 3 circuits? and not just 2 circuits for the 16A radial and 6A lights circuit
i.e
1. Garage SUpply
2. Radial Sockets
3. Lights
6. Am i right that the disconnection time for the 3 circuits should 5s for the 40A garage supply, as it is over 32A and a distribution circuit? And the 16A radial and 6A light should both be 0.4s?
7. For the garage supply cable circuit which reference method from appendix 4 do i put? `As the cable is both clipped direct and buired in ducting? Do i put ref C and B?
8. For the garage supply cable circuit do i put number of points served as 1? i.e the consumer unit?
9. For the garage supply cable circuit in the maximum permitted Zs, i am really struggling to find a definitive figure. As the protective device is a 40A 1361 fuse, which isn't listed in the tables in BS7671 or the OSG. I did read somewhere that 1361 fuses have now been reclassified as BS 88 but the only fuses listed are BS 88-3 in table 41.4, but they are 32A and 45A not 40A. There are BS 88 40A fuses listed in table 41.6 but they are for Uo of 55v.
So my question is 2 parts, i) are BS 1361 now classed as BS 88? and ii) as i can't find a tabulated figure 40A BS88? should i use manufacturers instructions, as i found this link with states the Lawson's ME40A fuse stating 1.4 ohm's?
http://help.tradingdepot.co.uk/electrical/lawson-fuses/lawson-fuses-application-data/
10. On the garage supply cable circuit for RCD operating times boxes, do i just put N/A in the boxes?
11. For the 16A radial circuit, for the maximum Zs permitted by BS7671 do i put 2.73ohm's as stated in table 41.3 for type B 60898 breakers?
12. For the 6A light circuit, for the maximum Zs permitted by BS 7671 do i put 7.28 ohm's as stated in table 41.3 for type B 6088 breakers?
13. Am i right that as if i do R1 + R2 test, i then don't have to also do R2 test?
14. For the box Maximum measured earth fault loop impedance Zs, when i do Zs test on the radial circuit and light circuit by linking Phase and CPC and testing between Phase and CPC at each accessory point, do i take the highest reading as my Zs value?
The reading i am getting is 0.31 ohm's,
and since Zs = Ze + (r1 + r2)
Zs = 0.22 + 1.34
Zs = 1.56
So surely my reading should be 1.56 ohm's not 0.31 ohm's
Sorry for the war and peace post, and sorry for so many questions, i hope you don't mind answering all my questions and can excuse my ignorance but i am learning haha
Cheers
The installation in question is on a domestic TNS supply. The installation is in a detached garage, which incorporates the supply cable, consumer unit, 16A radial circuit, and 6A light circuit. The supply to the consumer unit is run in 6mm SWA externally and 6mm T&E (plus 6mm single for earth) internally. The 6mm supply cable is protected by a 40A switch fuse, fed with 16mm tails from henrys blocks.
I have got a few questions about filling out the EIC.
1. On page 2 of the EIC under the section SUPPLY CHARACTERISTICS, under sub section Characteristics of primary supply overcorrect protectective devices On the main cut out fuse, there is no clear markings of BS EN number, so i phoned western power to enquire. When i eventually got hold of someone who could supposedly answer my questions, they told me it should be BS 88 part 2, with 16KA breaking capacity (and the Ze was 0.8 ohms for the Ze enquiry test). Its the "should be" part that I'm unsure of, do i need to keep ringing them to get a more definitive answer? Or should i just put down what he said? I was also under the impression that all domestic cut outs were supposed to be BS 1361's?
2. Under the section PARTICULARS OF INSTALLATION AT THE ORIGIN, where you have 4 boxes for:
Measured Ze, Maximum demand, Number of smoke alarms, Protection measure(s) for fault protection.
What do you put in the box entitled Protection measure(s) for fault protection? Is it switch fuse? Or is it RCD/RCCB?RCBO? Or is it EEBADS? Or all of them?
3. Again under the section PARTICULARS OF INSTALLATION AT THE ORIGIN, where you have the sub section Main switch/Switch-Fuse/Circuit Breaker/RCD do i fill out the details for the 40A switch fuse, and not the consumer unit RCD?
i.e BSEN 60947-3, 2 poles, 230v, 40A etc
4.Under the section SCHEDULE OF ITEMS INSPECTED, under sub section 6.0 OTHER METHODS OF PROTECTION 6.1 Basic and fault protection, what do i put for the boxes titled:
a) SELV LOCATION
b) PELV LOCATION
c) Double insulated/Reinforced insulation
d) Electrical seperation for one item of equipment
For a) SELV, do i just tick the box? and what do i put in the location box, it is just garage?
For b) PELV do i just put N/A
For c) Double insulated/Reinforced insulation do i tick the box due to the SWA cable? and in location box put clipped direct/underground?
For d) Electrical seperation for one item of equipment do i just put N/A?
5. On page 4 of the EIC, should i put down 3 circuits? and not just 2 circuits for the 16A radial and 6A lights circuit
i.e
1. Garage SUpply
2. Radial Sockets
3. Lights
6. Am i right that the disconnection time for the 3 circuits should 5s for the 40A garage supply, as it is over 32A and a distribution circuit? And the 16A radial and 6A light should both be 0.4s?
7. For the garage supply cable circuit which reference method from appendix 4 do i put? `As the cable is both clipped direct and buired in ducting? Do i put ref C and B?
8. For the garage supply cable circuit do i put number of points served as 1? i.e the consumer unit?
9. For the garage supply cable circuit in the maximum permitted Zs, i am really struggling to find a definitive figure. As the protective device is a 40A 1361 fuse, which isn't listed in the tables in BS7671 or the OSG. I did read somewhere that 1361 fuses have now been reclassified as BS 88 but the only fuses listed are BS 88-3 in table 41.4, but they are 32A and 45A not 40A. There are BS 88 40A fuses listed in table 41.6 but they are for Uo of 55v.
So my question is 2 parts, i) are BS 1361 now classed as BS 88? and ii) as i can't find a tabulated figure 40A BS88? should i use manufacturers instructions, as i found this link with states the Lawson's ME40A fuse stating 1.4 ohm's?
http://help.tradingdepot.co.uk/electrical/lawson-fuses/lawson-fuses-application-data/
10. On the garage supply cable circuit for RCD operating times boxes, do i just put N/A in the boxes?
11. For the 16A radial circuit, for the maximum Zs permitted by BS7671 do i put 2.73ohm's as stated in table 41.3 for type B 60898 breakers?
12. For the 6A light circuit, for the maximum Zs permitted by BS 7671 do i put 7.28 ohm's as stated in table 41.3 for type B 6088 breakers?
13. Am i right that as if i do R1 + R2 test, i then don't have to also do R2 test?
14. For the box Maximum measured earth fault loop impedance Zs, when i do Zs test on the radial circuit and light circuit by linking Phase and CPC and testing between Phase and CPC at each accessory point, do i take the highest reading as my Zs value?
The reading i am getting is 0.31 ohm's,
and since Zs = Ze + (r1 + r2)
Zs = 0.22 + 1.34
Zs = 1.56
So surely my reading should be 1.56 ohm's not 0.31 ohm's
Sorry for the war and peace post, and sorry for so many questions, i hope you don't mind answering all my questions and can excuse my ignorance but i am learning haha
Cheers
