Discuss Exam question in the Electrical Testing & PAT Testing Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Reaction score
0
Question 48 on this mock paper I have asks,

A 3-Core, 2 Metre flex, has a calculated earth bond reading of 0.152 Ohms. Which nominal conductor c.s.a would this relate to:
A 0.75mm²
B 1.00mm²
C 1.25mm²
D 1.5mm²

What is the answer, how do you calculate it, and where in the COP is this info please?
 
Welcome to the forum.
The question appears to mix up two different disciplines: fixed wire testing and in service inspection and testing.
I am assuming the question is about in service inspection and testing since you mention the COP.
Appendix VI contains the resistances of flexible cords, which would be your reference for the answer.

However the answer does not match with the method of testing the "earth bond" as the measurement should only encompass the circuit protective conductor of the flex, yet the question appears to be assuming an R1+R2 value for the calculated "earth bond".
 
I was wondering whether the figure they provided was actually an R1+R2 value because 0.152/4 (2m there and back) = 0.038... 0.001 ohms off the figure for 1m of single 0.5mm
 
PAtesting generally only refers to the cpc reading as it is the only prescribed continuity test.
 
Wierdly worded question but I doesn't the 0.152 value given include 0.1 Ohms for the appliance?
(not that they mentioned any appliance)

2 Metres at 0.75 mm2 gives a resistance value of 0.052 Ohms
I do believe you have solved the problem we have overlooked the 0.10 ohm to be added to the cable resistance.
 
I think patdev has it.
It would have been just so easy for the question to state "calculated maximum permissible earth bond reading of 0.152Ω"
A calculated reading is what reading you would expect to see on the meter when you test and not the maximum reading you could get to allow the tested equipment to pass.
I am obviously still learning the language of C&G speak !:(
 

Reply to Exam question in the Electrical Testing & PAT Testing Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock