Trainees! What Would You Do Here? (pop Quiz)

[happysteve]

Eh up!

A little scenario and a few questions related to it. It can be tackled by anyone at pretty much any level, so have a ponder and reply with your thoughts below. It's probably not the sort of thing you'll come across in your courses, but you'll certainly come across scenarios such as this in the real world...

The idea is to get you to cut through the usual BS about what you can and can't do, and get you looking at the statutory and non-statutory regs and guidance to either get a defiinitive answer, or at least form an informed opinion. I'll give you some hints on places to look to get their answers.


SCENARIO

You have been called to a domestic property - a fairly swanky-looking first floor apartment - where the owner reports that the bathroom extractor fan has stopped working. The details of the setup are as follows:

- The fan is powered from the lighting circuit, which is protected by a 10A BS EN 60898 Type B circuit breaker (as with many swanky apartments, there are LOTS of GU10 downlights!).

- There are no RCDs on any circuits in the property. The label on the consumer unit says it was installed in 2001.

- The fan is activated by a wall-mounted light switch (outside the bathroom) that turns on the bathroom lights, and has a run-on timer (so as well as a switched line, there is also a permanent line to the fan).

- There are no signs of an isolation switch for the fan.

- The fan is ceiling mounted.

- The height of the ceiling is 2m above floor level.

- The fan is adjacent to the shower (not over it), you estimate within about 400mm of the edge of the shower.

- The fan is not marked with a Class 2 label, and there is an Earth connection.

- The fan is rated IP44.

- The bathroom is interior, it does not have any windows or skylights.

Following safe isolation procedure and using appropriate dead tests, you confirm that there are no problems with the existing fixed wiring:

- Insulation resistance (L+N tied together to E): >299MΩ
- R1+R2: 0.60Ω, R1+Rn: 0.48Ω
- Switched line behaves as expected

As it is safe to do so, you also perform a measurement of the earth loop impedance at the fan: Zs = 0.80Ω.

You conclude that the old fan is faulty and needs replacement. Fortunately, a direct replacement (same model number) is available. As such, the client instructs you to replace the fan.

For the following questions, state:

- what is REQUIRED, or NOT REQUIRED, and if you can back it up with a reference (e.g. to BS 7671, Building Regs/Approved Document, other statutory regulation).

The Approved Documents are available from the Planning Portal: https://www.planningportal.co.uk/info/200135/approved_documents "Part P" relates to electrical safety in dwellings.


QUESTIONS

(1a) Does the work REQUIRE notification to Building Control?

(1b) Would you notify it?



(2a) In addition to the tests you have already done above, are there any other tests that are REQUIRED?

(2b) Would you do any other tests?



(3a) Does the work REQUIRE an Electrical Installation Certificate (EIC), a Minor Electrical Installation Works Certificate (MEIWC), an Electrical Installation Condition Report (EICR), something else, or none of the above?

(3b) What documentation, if any, would you issue?



(4a) Are there any additions or alterations to the existing circuit that are REQUIRED (in addition to the fan replacement itself)?

(4b) Are there any additions or alterations to the existing circuit that you would ADVISE the client need to be done?

(4c) For (4a) and (4b), do any of these REQUIRE notification to Building Control (and under what circumstances)?

(4d) If you advise the client of recommended additional work, what would you do if the client declined?


Finally, just to throw another fly in the ointment:

(5) You pick up the fan from the wholesaler. You have a quick read of the installation instructions. Under "electrical installation" the instructions state: "Means of double pole disconnection must be incorporated in the fixed wiring in accordance with the Wiring Regulations." You also notice that on the wiring diagram there is an item marked "3 amp fuse." Does this change any of your answers to any of the previous parts?



If you want to have a go at just part of it, or all of it, or ask questions... just fire away! I'll see how you get on, then I'll put up my thoughts, see what you think!

 

[Karin]

cheers for the post steve! i'll have a crack at this sometime today

 

[Karin]

top questions, really got me thinking, finding this really hard as i can't find much specific reference to replacement fittings or maintenance on fitting compared to alterations and additions. is there somewhere in BS7671 this is dealt with?

but here's a start..

1.
a) It is a replacement fitting that does not alter the circuit. Therefore it is non-notifiable work
Approved Document P, 2.7
b) no


5.
some thoughts to float around..

537.2.1.1 - in a TNS or TNCS (which this example must be) installation double pole isolation is NOT required. backed up by 537.3.2.5
which means that the 60898 breaker already in place for the lighting circuit 537.3.2.1 could be considered acceptable.
537.3.2.4 may however be used to argue that using the breaker is not "convenient". distance from board/working in dark in interior room..

however, a requirement for a 3A fuse would negate that argument as you'd be altering/adding to the circuit anyways. it would become notifiable work as the circuit serves a special location. and RCD protection would now be required (701.411.3.3)
a switched FCU would cover isolation purposes as well as fusing

 

[Karin]

3.
a) can't find anything saying a replacement fitting REQUIRES certification
b) a MWC may be an appropriate way of formalising work done.

but this again may be subject to change if i've missed a description of replacement works somewhere

 

[Karin]

2.
i would inspect/test the supplementary bonding (it's got to be there, 16th edition). am i required to for this? again, not sure. going to need some guidance here i feel..

 

[happysteve]

Really, really good answers, karin! I'm out n about at the mo, will respond more later... But you've got exactly the right approach and I'm dead impressed.

Anyone else, please chip in and share your thoughts!

 

[happysteve]

Well, here's my attempts at answering my own questions! Others may disagree, and I'm very open to debate (particularly if backed up by references).

top questions, really got me thinking, finding this really hard as i can't find much specific reference to replacement fittings or maintenance on fitting compared to alterations and additions. is there somewhere in BS7671 this is dealt with?

The relevant bits of the Regs are 132.16, 610.4 and 633. They don't say much about notification. Additions and alerations are also mentioned in the MEIWC notes (p418 of the BYB). There's nothing in the Regs about "like-for-like" or "direct replacements." So it looks like you've found all there is to find in the Regs.

but here's a start..

1.
a) It is a replacement fitting that does not alter the circuit. Therefore it is non-notifiable work
Approved Document P, 2.7
b) no

I agree with this, and spot on for the correct reference. Approved Document P, non-notifiable work: 2.7 Regulation 12(6A) sets out electrical installation work that is notifiable. All other electrical installation work is not notifiable – namely additions and alterations to existing installations outside special locations, and replacements, repairs and maintenance anywhere." So it would not need notifying, and I wouldn't.

2.
i would inspect/test the supplementary bonding (it's got to be there, 16th edition). am i required to for this? again, not sure. going to need some guidance here i feel..

There may well be supplementary bonding in place, well spotted.

(2a) Are any other tests REQUIRED? I suppose the big question is: is the work you are doing and addition or an alteration, or not? Neither of the words are defined in Part 2 of BS7671, so we take the general understood uses. Are you making an addition? No. Are you altering the electrical installation? I would argue "no" as you are not altering the electrical characteristics. So the work is not within the scope of an addition or an alteration, and I would argue that no other tests are required. Regulation 132.16 says, "... the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate."

(2b) As for whether I would do any other tests or not: I would determine the adequacy of the earthing and main equipotential bonding arrangements. If accessible, I would check to see if there was any supplementary equipotential bonding in the bathroom, as you suggested there should be. I would comment on the above in the box marked "Comments on the existing installation" on the MEIWC (see below). I would also repeat the Zs test, once I had connected up the new fan.

3.
a) can't find anything saying a replacement fitting REQUIRES certification
b) a MWC may be an appropriate way of formalising work done.

but this again may be subject to change if i've missed a description of replacement works somewhere

Both spot on, as far as I'm concerned!

(3a) No. Again, it is not an addition or an alteration. The "Notes" for the MEIWC states: "This Certificate may also be used for the replacement of equipment such as accessories or luminaires." I would argue that, if it was the intention of the Regulations that ALL work (including replacement of equipment) required a certificate, then the word would not be "may."

(3b) I would issue a MEIWC, doing all the essential tests, including commenting on the adequacy of earthing and main equipotential bonding arrangements.

5.
some thoughts to float around..

537.2.1.1 - in a TNS or TNCS (which this example must be) installation double pole isolation is NOT required. backed up by 537.3.2.5
which means that the 60898 breaker already in place for the lighting circuit 537.3.2.1 could be considered acceptable.
537.3.2.4 may however be used to argue that using the breaker is not "convenient". distance from board/working in dark in interior room..

however, a requirement for a 3A fuse would negate that argument as you'd be altering/adding to the circuit anyways. it would become notifiable work as the circuit serves a special location. and RCD protection would now be required (701.411.3.3)
a switched FCU would cover isolation purposes as well as fusing

Some really good thinking there! I would agree with your assessment of the need for isolation.

This fusing down of fans is a real PITA. 134.1.1 says: "... The installation of electrical equipment shall take account of manufacturers' instructions." Does a direct replacement cover "installation"? If it was easy to do, and by "easy" I mean is the feed for both the permanent L and switched L accessible and outside the zones, I might be tempted to put in a FCU; a switched one would include the "double pole isolation" requirement, but of course would also isolate the bathroom light. If the appropriate point of the existing wiring was not accessible, I would probably take account of the instructions as per 134.1.1, take a view, and then ignore it, on the grounds that it is a direct like-for-like replacement and I am not altering the existing installation in any way.

As for the whether the work would now be notifiable or not (if you added a fuse and/or an isolator)... I'm not so sure about your answer. You have a good understanding of section 701 of the Regs, and 701.411.3.3 that you state does mention "serving the location [containing a bath or shower.] However, the Building Regs have a different definition of "special location". I would take the view, from 2.6, 2.7 and 2.8 of Approved Document P that provided the addition or alteration itself wasn't within the "special location" (as defined by the Building Regs) then it is non-notifiable.

Going back to the Building Regs themselves:
"12. —(6A) (c) any addition or alteration to existing circuits in a special location."

This is genuinely ambiguous: to what does "special location" refer? Is it the addition or alteration? Or is it the existing circuits? My guts say the former, but that's all I've got! ~tin hat on~

Anyone got any thoughts on part 4 of the question?

Good stuff!

 

[Karin]

thanks for the responses Steve. certainly plenty to think about and a well thought out exercise.

As for the whether the work would now be notifiable or not (if you added a fuse and/or an isolator)... I'm not so sure about your answer. You have a good understanding of section 701 of the Regs, and 701.411.3.3 that you state does mention "serving the location [containing a bath or shower.] However, the Building Regs have a different definition of "special location". I would take the view, from 2.6, 2.7 and 2.8 of Approved Document P that provided the addition or alteration itself wasn't within the "special location" (as defined by the Building Regs) then it is non-notifiable.

"12. —(6A) (c) any addition or alteration to existing circuits in a special location."

This is genuinely ambiguous: to what does "special location" refer? Is it the addition or alteration? Or is it the existing circuits? My guts say the former, but that's all I've got! ~tin hat on~

rereading this i can really see your point!!

if you take the adding of an FCU and the replacement of the fan as individual actions then i can see how neither would be notifiable. in the same way that you wouldn't expect to notify the addition of an extra bedroom light just because it happened to be on the same circuit as a bathroom light.

could it be argued though, that in this case, work outside the special location (adding a fuse/isolator) has affected/altered the electrical characteristics of the circuit at a point which does physically fall in a special location.. ?
we might be splitting hairs on a Zs value, and the fuse would only increase safety, but in principle?

hmm, so using some of this thought train to have a go at section 4..

4.
a) no other work is required.

b) i would recommend RCD protection for the circuit to bring it up to current regulations, but if all supplementary bonding is fine i wouldn't push it
if the main equipotential bonding was undersized i would also mention it, especially if it looked to be an issue

c) would the RCD require notification? notifiable work can be..
12.-(6A)(a) the installation of a new circuit.
Part 2 BS7671 defines a circuit as an assembly of electrical equipment supplied from the same overcurrent protective device. overcurrent includes overload current and fault current (chapter 43). so to my reading, the addition of a device that alters the characteristics of the circuit in regard to either of these would be considered a "new circuit". here the RCD would be used as additional protection rather than fault protection, but it gives fault protection anyways by nature. so i think it would have to be considered. it may even increase earth fault protection to a level where it becomes a nuisance so i think it has to be included.
therefore it would be notifiable work.

the bonding? despite being part of ADS it does not come under any definition in building regulation 12.-(6A)(a)(b)(c) so would be considered non-notifiable work according to Approved Document P, 2.7

d) change the fan only and not try to fleece anyone for unnecessary work

anyone read that differently to me?!

 

[happysteve]

Anyone think anything different to karin? Or agree? Post below...

 

[GMES]

Come on Guys have a crack at it please, Steve has gone to a lot of trouble and it's all for the thrainees benefit.
Remember you don't have to worry in here about giving the wrong answer, it's all about having a go and learning along the way.

 

[hightower]

I completely plan to, but it's not the sort of thing I can do on the phone so it'll be tomorrow when I'm back in the office

 

[hightower]

Duplicate post

 

[hightower]

With regards #4, 701.411.3.3 requires that RCD protection be installed. Now I'm struggling to work out whether that would be a REQUIRED alteration or an ADVISED alteration. I'm leaning towards ADVISED alteration since it's a like for like replacement, however, I think I differ from Karin in that if the client refused I'd be inclined to walk away from the job. My reasoning behind this is every time we sign a certificate we scribble in a box that says our work is to BS7671 2008:2015, and I'm not sure how we could do that without complying to the latest regs. But then if that was true it would make it a REQUIRED alteration.

Fair enough the old fan was deemed safe enough by previous regs, so the new like-for-like fan should be just as safe without an RCD, but I'd be putting my name to something, so maybe it's just a 'cover my a***' mentality that I'd want an RCD fitting.

The thing is, I've done like-for-like pendant replacements etc without RCD protection, and was happy enough with that. I don't know whether it's that the fan is in a bathroom (and zone 2 if I read correctly) that makes me uneasy in this situation.

 

[happysteve]

Some more excellent answers on here! It's great to see you thinking about these things.

4.
a) no other work is required.

b) i would recommend RCD protection for the circuit to bring it up to current regulations, but if all supplementary bonding is fine i wouldn't push it
if the main equipotential bonding was undersized i would also mention it, especially if it looked to be an issue

I'd agree with those.

c) would the RCD require notification? notifiable work can be..
12.-(6A)(a) the installation of a new circuit.
Part 2 BS7671 defines a circuit as an assembly of electrical equipment supplied from the same overcurrent protective device. overcurrent includes overload current and fault current (chapter 43). so to my reading, the addition of a device that alters the characteristics of the circuit in regard to either of these would be considered a "new circuit". here the RCD would be used as additional protection rather than fault protection, but it gives fault protection anyways by nature. so i think it would have to be considered. it may even increase earth fault protection to a level where it becomes a nuisance so i think it has to be included.
therefore it would be notifiable work.

I'm not sure I'd agree here, though I can definitely see where you're coming from! To back up my point of view: the example MEIWC in Guidance Note 3 (GN3) (p110) includes the example where the circuit breaker is replaced by an RCBO to provide additional protection. Whilst "can be covered by MEIWC" does NOT equal "does not need to be notified" (could be doing minor works in a sauna, for instance!), in this case I believe we're alright. Providing we're not doing any work in the "zones" of the bathroom, it does not need notifying.

d) change the fan only and not try to fleece anyone for unnecessary work

Good-oh!

With regards #4, 701.411.3.3 requires that RCD protection be installed. Now I'm struggling to work out whether that would be a REQUIRED alteration or an ADVISED alteration. I'm leaning towards ADVISED alteration since it's a like for like replacement, however, I think I differ from Karin in that if the client refused I'd be inclined to walk away from the job. My reasoning behind this is every time we sign a certificate we scribble in a box that says our work is to BS7671 2008:2015, and I'm not sure how we could do that without complying to the latest regs. But then if that was true it would make it a REQUIRED alteration.

Fair enough the old fan was deemed safe enough by previous regs, so the new like-for-like fan should be just as safe without an RCD, but I'd be putting my name to something, so maybe it's just a 'cover my a***' mentality that I'd want an RCD fitting.

The thing is, I've done like-for-like pendant replacements etc without RCD protection, and was happy enough with that. I don't know whether it's that the fan is in a bathroom (and zone 2 if I read correctly) that makes me uneasy in this situation.

This is a good default attitude to have - consider your position, work out what you're prepared to do and what you aren't, and stick to it. And you're absolutely right about every time you sign your name, etc. So I can't fault your answer.

My personal view is that, if the work doesn't REQUIRE a certificate - and I'm just supplying one for piece of mind/doing a "proper job" etc - then I don't see how that would make me more responsible for the work I'd done than if I'd just replaced the fan and done a bang test.

So I think we're all up to speed and generally in agreement, albeit with subtle differences here and there? The only other thing I might advise is the provision of an isolator for the fan, since it is fed from the lighting circuit and there are no windows in the bathroom. This is referenced on page 74 of the IET's "Electrician's Guide to the Building Regulations."

A useful source of FAQs (and answers) that has a little more weight than this forum (venerable though it is) is the Electrical Safety First website, in particular: http://www.------------------------...tions/new,-rewired-and-similar-installations/

Have a look at Q1.70, Q1.76...

Stuff to take away from this:

- try to find things in black and white
- even then, stuff is still ambiguous
- where there is a difference between minimum requirements and "ideal, proper job" work out where you're comfortable working; on the other hand, don't do extra work where there is no point.

Cheers!

 

[hightower]

The only other thing I might advise is the provision of an isolator for the fan, since it is fed from the lighting circuit and there are no windows in the bathroom.

I was going to mention the isolation with it not having a window, but thought it had already been mentioned by Karin so left it.

Have a look at Q1.70, Q1.76...

Thanks, very useful - link saved for future reference.

Thanks for these questions, please do keep them coming as and when you find time - they are extremely useful. I couldn't find time to reply earlier in the week, but I still read them and the responses and they got me thinking, so very useful.

Shame nobody else got involved, I know @rolyberkin would have if he wasn't on holiday, but we need more trainees involved in these to open up the dialogue and debate the points within.