Some questions regarding reinstating the supply fuse for live testing

[Amp David]

Nazoom a couple of books which will help you with the 2391

17th Edition IEE Wiring Regulations: Inspection, Testing and Certification (IEE Wiring Regulations, 17th edition) by Brian Scaddan

Practical Guide to Inspection, Testing and Certification of Electrical Installations: Conforms to 17th Edition IEE Wiring Regulations (BS 7671:2008) and Part P of Building Regulations by Chris Kitcher

These sould answer your questions and explain what you are asking.

Hope it helps

If you can't find the answers in this book, give it up, please or you're gonna kill someone, if not yourself!

 

[Paul.M]

GN3, page 115.

 

[Sparky Ninja]

Basically I am asking when Life testing i.e Zs, Ze, PFC, and PSCC do I need to re-energise the supply by putting the 100A fuse back and unlocking the isolater then turn the main switch On at the consumer unit for these test?

Much appreciated.

Relax!!!

We are going to help you as much as we can.

Is this question an example from a mock exam? It seems a bit strange having the fuse removed in the first place, as it's a practice we are not supposed to carry out, it's usually the supply authority who remove/replace fuses.

 

[nazoom]

I am currently training at OLCI. It has been while since my workshop. Now I can't remember what happens in details! but I do remember taking out the 100 A fuse and locking the isolater with a key but I can't remember what happens to the 100 A Fuse in the case of each test: Ze, Zs, PFC, and PSCC?

 

[telectrix]

I did look in theses books and other books and even searched Utube and I have bought lots of DVDs to help me with this but no good. Also it has been while since I was in the workshop for this course and now i cant find the answer to these questions and they are very important please I don't know who can help me with this any more! My questions are simple and important. My exam date is this January 18th. And I am, freaking out as this will only get worst if I don't find the answers to these questions. So please Help!


Basically I am asking when Life testing i.e Zs, Ze, PFC, and PSCC do I need to re-energise the supply by putting the 100A fuse back and unlocking the isolater then turn the main switch On at the consumer unit for these test?

Much appreciated.

simple answer to that question........... YES Ffor Zs. Main switch OFF for Ze. these answers are all in the books AMP David mentioned.

 

[tony mc]

Have a look at the testing forum on this site, Phil 7677 posted a series of testing videos

http://www.electriciansforums.net/electrical-courses-electrical-nvqs/24478-testing-videos.html

hope the link works

 

[ezzzekiel]

carrying out a live test is dangerous , however it is not dangerous at all on a dead installation unless you trip over your test equipment and bang your head, but you may struggle to understand the test results with a dead installation and a sore head.

 

[Sparky Ninja]

I am currently training at OLCI. It has been while since my workshop. Now I can't remember what happens in details! but I do remember taking out the 100 A fuse and locking the isolater with a key but I can't remember what happens to the 100 A Fuse in the case of each test: Ze, Zs, PFC, and PSCC?

Ok well I'll be honest and say that I donk think taking out the fuse is a good idea when training students, it leads to confusion. Locking off of the main switch and testing with an approved tester and proving unit will achieve safe isolation.
So breaking down the live tests you have stated..
Ze, PFC & PSCC can be measured with the main switch still locked off, by testing on the supply side. Remember that if it is possible to carry out a test with as little of the installation energised at the time then it is a safer method of testing.
I assume you understand test procedures (removal of main protective conductor etc)..
Zs, however, will need to be measured at the furthest point of each circuit. This is why it is done after Ze, to verify presence of sufficient earthing before energising the system.
So to carry out Zs, isolate each MCB then remove the lock off from the main switch.
Now, one circuit at a time, energise and obtain the Zs readings by measurement. Some of the circuits may not be applicable at this test if Zs has been obtained by calculation.

Hope this made sense, but back to the fuse.. It must be inplace for you to be able to carry out live testing.

 

[accordfire]

When did DNO's start allowing their fuses to be removed? Especially by "Joe Bloggs Inc, trainee Electrician"?

I also thought that's why a lot of the DNO's were insisting that REC switches be fitted now too, which indeed should be locked off when carrying out some of the "life" tests.....

I get more scared by the day, at the state of some of what is coming into the industry as apparently "qualified" in some way.

How long until we get the weekly part by part magazine on becoming a qualified electrician - this week's copy with a "build your own GS38 tester"?

 

[nazoom]

Many thanks goes out to you widdler. You might have saved my and peoples lives!

 

[telectrix]

When did DNO's start allowing their fuses to be removed? Especially by "Joe Bloggs Inc, trainee Electrician"?

I also thought that's why a lot of the DNO's were insisting that REC switches be fitted now too, which indeed should be locked off when carrying out some of the "life" tests.....

I get more scared by the day, at the state of some of what is coming into the industry as apparently "qualified" in some way.

How long until we get the weekly part by part magazine on becoming a qualified electrician - this week's copy with a "build your own GS38 tester"?

built mine out of a tail light bulb from a transit, a 68ohm resistor, 2 croc clips, and some odd bits of blu-tack and tape.

 

[accordfire]

built mine out of a tail light bulb from a transit, a 68ohm resistor, 2 croc clips, and some odd bits of blu-tack and tape.

I remember that episode of Blue Peter lol!

 

[Paul.M]

built mine out of a tail light bulb from a transit, a 68ohm resistor, 2 croc clips, and some odd bits of blu-tack and tape.

I've done the same but its rubbish for life testing with the bullet pulled

 

[RME ELECTRICAL]

These test are all live testing the main fuse must be in, with the main switch turned off, do ur tests at incoming tails of main switch

 

[SW1970]

When did DNO's start allowing their fuses to be removed? Especially by "Joe Bloggs Inc, trainee Electrician"?

I also thought that's why a lot of the DNO's were insisting that REC switches be fitted now too, which indeed should be locked off when carrying out some of the "life" tests.....

I get more scared by the day, at the state of some of what is coming into the industry as apparently "qualified" in some way.

How long until we get the weekly part by part magazine on becoming a qualified electrician - this week's copy with a "build your own GS38 tester"?

3,000 ClubCard points with your Fluke 1654B.