UK Using Armoured as CPC, how to carry R1+R2

[Amnesh Singh]

Can anyone please help me, HOW to Calculate R1+R2 on 4 core three phase & neutral SWA, Armour Steel Sheet is Used as CPC. How to fill the Electrical Installation Form. This scenario is in AM2 Inspection and testing filling Certs Exam? Please reply with best answers.
Any members those who took AM2 Test please put some light on this matter. How you guys done R1+R2 using armoured sheath as CPC.

With Regards
Amnesh

 

[Ian1981]

Can anyone please help me, HOW to Calculate R1+R2 on 4 core three phase & neutral SWA, Armour Steel Sheet is Used as CPC. How to fill the Electrical Installation Form. This scenario is in AM2 Inspection and testing filling Certs Exam? Please reply with best answers.
Any members those who took AM2 Test please put some light on this matter. How you guys done R1+R2 using armoured sheath as CPC.

With Regards
Amnesh

Add the copper resistance of R1 over the required length to the resistance of the steel armour over the required length. Below is a table for resistances of common copper conductors and the R2 values of the armour.
The below table might be easier to read.
A

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[westward10]

Not done an AM2 so is this a calculation from gathering info as per Ian's Tables with no continuity meter.

 

[SparkyChick]

If it's the test and inspection portion, unless it's changed since I took mine... you measure it, just as you would in the real world.

You shouldn't be calculating R1+R2 except to verify it if the answer you get seems too high. R1+R2 is an important step in Initial Verification to confirm the existence of a CPC at each point in the circuit (and also polarity).

 

[Amnesh Singh]

Add the copper resistance of R1 over the required length to the resistance of the steel armour over the required length. Below is a table for resistances of common copper conductors and the R2 values of the armour.
The below table might be easier to read.
AView attachment 54034
[automerge]1574500227[/automerge]
View attachment 54036View attachment 54036

Thank You Very Much “Ian”.
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If it's the test and inspection portion, unless it's changed since I took mine... you measure it, just as you would in the real world.

You shouldn't be calculating R1+R2 except to verify it if the answer you get seems too high. R1+R2 is an important step in Initial Verification to confirm the existence of a CPC at each point in the circuit (and also polarity).

Thank You Very Much Mr Sparky Chick

 

[SparkyChick]

Thank You Very Much Mr Sparky Chick

I don't know where you hang out, but here in Wales chick's are women

If you need to use a title, my preferred title is Miss., Madam if you want to be super polite ... Ms. will get you stabbed with a 500v insulation resistance test because that's an invention of modern day feminists who think we are all under paid, under represented victims incapable of speaking up for ourselves and... dare I say... having opinions of our own... especially if they don't align with the feminist collective thinking.

So, in short... it's Miss. SparkyChick to you... or SC for short. But don't assume all sparks are men

p.s. My avatar... how many men do you know that wear skirts and boob tubes??? On second thoughts... don't answer that, it might be too much information

 

[Amnesh Singh]

I don't know where you hang out, but here in Wales chick's are women

If you need to use a title, my preferred title is Miss., Madam if you want to be super polite ... Ms. will get you stabbed with a 500v insulation resistance test because that's an invention of modern day feminists who think we are all under paid, under represented victims incapable of speaking up for ourselves and... dare I say... having opinions of our own... especially if they don't align with the feminist collective thinking.

So, in short... it's Miss. SparkyChick to you... or SC for short. But don't assume all sparks are men

p.s. My avatar... how many men do you know that wear skirts and boob tubes??? On second thoughts... don't answer that, it might be too much information

I m sorry while typing i did type Miss , but may be finger touched the mobile screen by mistake.

regards
Amnesh

 

[westward10]

Take more than a miss(print) to upset our SC