2394 help!

[n9wo83]

Hi all

Trying to revise for my 2394 exam. Got a question about the essential action required before disconnecting a main protective bonding conductor for a periodic inspection and test and any dangers that would arise if this action wasn't taken.

Having some trouble finding the answer in the books, any help greatly appreciated.

 

[Marvo]

The only essential action I can think of offhand is to completely isolate the supply. Maybe one of the UK members can come up with something better.

 

[Paul.M]

"essential action required before disconnecting a main protective bonding conductor for a periodic inspection and test and any dangers that would arise if this action wasn't taken."

Its not clear in the books as you say but here is your answer, normally I dont give out the answers to questions but in this case it will be very difficult to find out for yourself.

To carry out a Ze earth fault loop impedance test you have to disconnect and earth bonding to incoming services (water, gas, oil, structural metal work etc). Before disconnecting the bonding conductors at the C/U you must inform the people on site on to use, touch anything that uses pipes. So dont be jumping into the bath or shower, tell (dont ask, tell him/her) the boiler engineer to have a ten minuet break and step away from the boiler. C&G's may want you to phrase that a bit like this:- You have to obtain permission from the head of the work site (or home owner) before disconnecting the earth bonding and inform any other trades on site not to work on exposed conductive parts. This is due to not having an earth return path for these conductive parts and therefore not protected against electric shock if a fault occures whilst your carrying out the testing.

Hope that helps?

 

[n9wo83]

That was all I could think of too Marvo!

Thanks for the help Paul.

 

[Paul.M]

Before you isolate you HAVE TO GAIN PERMISSION TO DISCONNECT ANY EARTHING THAT MAY BE A DANGER TO OTHER AND MAKE THEM AWARE OF THE DANGERS.


The question has nothing to do with isolation, thats the next stage.

 

[n9wo83]

Ok thanks Paul. Seems to be coming back to me now. I remember my instructor saying something along these lines.