2392 theory exam: maximum earth loop impedance

[septiclecky]

Multiply MCB tripping current by rating factor ie. Type B X 5 Type C X 10 Type D X 20 Divide 230 Volts by result

Then multiply by 0.8 for correction factor.

B 6 Amp 60898 MCB

6X5=30

230/30=7.67

7.67 X 0.8= 6.14 ohms

Maximum Zs 6.14 ohms corrected

Hope this helps CJS

As I have already pointed out in an earlier post it's 110v not 230vheadbangheadbang

 

[louisIV]

Plumbers version is the way I way taught in my coursework.Just curious LouisIV. Is there a practical part to the 2392 as ive done the theory exam and passed but never done the practical and was never told about it if there is one. Thanks

Hi m4tty. Sorry to go quiet on you. I don't know if the course has changed since you took it, but yes - there's a practical exam to get the qualification. To quote from the NICEIC course guide:

'The 2392-10 is assessed by both an on-line multiple choice assessment and a practical assessment on a simulated test rig.(snip) to receive a 2392-10 certificate, candidates must be successful in both units.'

I haven't taken the practical part yet, but just got the result through on the theory - I got 98% (ie 49/50)! The pass mark is 75%, so I'm well pleased with that. :^O

As it turned out, I didn't get a question on calculating Zs, but it's good to know anyway. Thanks for all your advice everyone.

LIV

 

[look forward]

trying to get a second post so I can read the answer!!!!!