I.T room

[Andy™]

543.7.2.1(ii){c}If I read it wrong I will stand corrected

post removed - wrong info

 

[Andy™]

Assuming the cable is installed correctly obviously.

that would apply to just about every reg in the book

 

[ianmacd]

[quote name='Andy

 

[Andy™]

i missed 543.7.2.1(ii)© - for some reason i looked at 543.7.1 when it was mentioned above....

your right ianmacd & musicspark - if you have 2 identical radials, you can join the earth at the ends of each radial

 

[musicspark]

Thanks Andy, Guinness

you are well respected here, and I thought I had misread that reg.

I do agree with you though; it seems like a strange approach connecting one circuit to another

What would you put on the cert for R1+R2?

Any kind of ring or:

radial with additional CPC for sockets or,

protected singles with4mm CPC (belt and braces for nearly all methods and accessories)

put the kettle on

 

[ianmacd]

What would you put on the cert for R1+R2?

Test from the furthest socket on that radial having linked L & both CPC's together in CU? Agreed its not a very good solution.

 

[Andy™]

Thanks Andy, Guinness you are well respected here, and I thought I had misread that reg.

I do agree with you though; it seems like a strange approach connecting one circuit to another

What would you put on the cert for R1+R2?

Any kind of ring or:

radial with additional CPC for sockets or,

protected singles with4mm CPC (belt and braces for nearly all methods and accessories)

put the kettle on

maybe R1R2 on each circuit as per normal radial, then connect the earths?

it just seems wrong, having 2 circuits share the same conductors

 

[peteinwilts]

Hi Guys

I am not an electrician and by far an expert in electrics, but am in the technical industry and in the past I have had to troubleshoot several schools where the PC's shock students or strange results on PC's\Servers that were caused by shoddy wiring and circuits not delivering enough current.

A PC's startup current is greater than running, and as school classes start their systems at the same time, would need to think of the worst possible scenario. The average school PC will have 350-400w PSU's which will rarely deliver more than 75% of the spec.

If the system is 'average' for schools, rarely more than 180-200w would be consumed. However, if the PC's are in a design or engineering class, they may be spec'd as high as 600w and may use 400w in real terms (a collegue has a 900w PSU in his system).

As spec'd before the average LCD is around 1A, but if a design class may consume more as larger monitors consume more power.

If a server is employed within the class (although most are tucked away in Server rooms), this can be as high as another KW.

Lastly the suggestion the network may require different trunking. Unless the CAT6 has very good shielding, with extra sheilding at junction points, then the network should always be in different trunking. Data cables running across power cables often cause data corruption causes additional CRC checks creating a slow network... This is a headache I often find myself troubleshooting as the technical equipment is often incorrectly blamed...

Not sure if this helps... just a view from a different direction!

Cheers

Pete

 

[ian932]

http://www.theiet.org/publishing/wiring-regulations/mag/2008/26-5437earthing.cfm?type=pdf