Discuss Struggled with this one in the Electrical Wiring, Theories and Regulations 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
17
Where the measure of automatic disconnection is employed, fault protection may be provided by
1. Protective earthing only
2. Protective equipotential bonding only
3. Protective earthing and protective equipotential bonding
4. Electrical separation
 
I think 4 is the only one with a chance of working, bonding and earthing wouldn't work without ADS, need some way to disconnect the supply.
Separation would work if it puts things far enough apart there's no chance of a fault eg electricity pylons, although i doubt it's common in domestic.
 
i'd say#1 is the answer. some would argue #3, but bonding is not required for fault protection. bonding is there to prevent electric shock when in contact with both an exposed conductive part and a bonded service ( under fault conditions).
 
This is one of the instances where BS7671 needs to be sorted out. Changing from EEBADS to ADS was a joke.
Both EEBADS and ADS are protective protective measures which according to BS7671 require both basic protection and fault protection.
Basic protection is provided by basic insulation of live parts, barriers, enclosures, obstacles or by placing out of reach.
Fault protection is provided by protective earthing, protective equipotential bonding and ADS.

So for the question if the protective measure ADS is being used, there should already be in place protective earthing and protective equipotential bonding. That’s answers 1, 2 and 3 out of the way.
Other measures for providing fault protection are:
(i) SELV
(ii) PELV
(iii) FELV
(iv) double or reinforced insulation and
(v) electrical separation.
 
411.1 is just a description of a particular protective measure, there’s no requirement to provide that particular protective measure.
Also, installations can and do have more than one protective measure.
 
I would have put 3 but after reading the response by spinlondon it makes a sense.
I hate these questions, I personally think this question should be worded differently maybe mention ADS in the question to make it more clear.

Where the measure of "Automatic
Disconnection of Supply" is employed............
 
Is as though they're trying to be clever would be better to ask what other methods could be included, but the way I read it is you have an RCD at the board and they are now asking how do you create fault protection for your circuit, which you have no idea about location of or what it's for
 
I would say it is a bad question and they got the answer wrong.

The way I read the question is that a measure of automatic disconnection, not the protective measure "Automatic Disconnection of Supply", is in place what is needed to provide fault protection for this circuit.
Based on BS7671 the protective measure "Automatic Disconnection of Supply" has three parts listed under fault protection: protective earthing, equipotential bonding and automatic disconnection.
You have one in place and you need the other two to complete the requirements for ADS.
Answer 3.
 

Reply to Struggled with this one in the Electrical Wiring, Theories and Regulations 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