Bathroom light Z2, RCD or SELV, that is the question

A same old question so be patient with me! I want to put a zone 2 light in the bathroom so figure a SELV will do, the idea being I don't then need to put a RCD in the lighting circuit. My CU is the "older" type with MCBs only, no RCD.
I have read another thread in here which the regs say even SELV needs a RCD but then someone says there has been an amendment to the regs to remove that requirement. To me one of the main purposes of SELV circuits are isolation and so a RCD on the primary (230V side) will not protect against earth leakage on the sec side (where the lamps are).

I've looked at screwfix lamp (43441) it's IP44 and good for zone 2 but no mention of SELV!? Maybe 10959 might do but again it is not clear if SLEV or not.

I'd be interested in seeing the amendment2, is that on the iee webby?

 

Darn it..I was hoping not to have to change the CU as I'd need to do two, the off peak too. It's like I need to spend £150+ just to change a light fitting!

I notice the bathroom has a small storage heater (not in zone 2) and I guess that needs a RCD too.

I think.. a RCD in the tails, wouldn't that be a 100mA device whereas the lighting needs a 30mA device?

 

I just found the amendment3, of note, all CU are to be metal not plastic. However I do think regs can be read in different ways (within good engineering practice) he's a guy saying common sense.

I know it's good for business to keep referring to what's "legal" and some people like to stay over complant so not to be open to challenge. Anyway..


The Main Changes in Amendment 3

The significant changes to be included in the amendment 3 are:

• Some layout changes
• Expanded definitions
• Some new regs
• UK specific regs
• Some new special locations
• Alterations to test certificates

UK Specific Regs- There are now some new regulations which are specific to the UK. Any new UK regs will end in a .200 number.

Definition of Competent- “Competent” persons will now be defined as “Instructed” persons.

RCDs for ALL Sockets- Reg 411.3.3 now refers to RCD protection for ALL socket outlets unless i) it is specifically labeled ii) a documented risk assessment has been carried out.

Lower Max Earth Loop Impedance Values- Zs values to take into account the Cmin factor which is for Minimum Voltage Factor. For low voltage supplies Cmin is given as 0.95 which will lower all the permitted values.

Plastic Consumer Units- Reg– Reg 421.1.200 – Consumer Units, Switch Boards and assemblies in domestic electrical installations are now to be made of non-combustible material such as metal, or enclosed in a fire proof boxing or enclosure. There is a proposed extended implementation period until January 2016 (presumably to allow the manufacturers to sell off all their plastic stock and make lots of metal ones!).

Electro Magnetic Compatibility- Reg 512.1.15 – The designer of an installation must ensure that all fixed electrical equipment is designed and manufactured in accordance with the EMC Directive. Manuals for equipment should be kept as proof of compliance. An CE marked apparatus would conform to this. An example would be of a power supply to a motor inducing an EMF in adjacent cabling or equipment.

Escape Route Wiring- Wiring on escape routes should be supported and fixed so it is not liable to collapse in the event of a fire. This would include the use of metal cable ties, metal containment and support fixings which would not fail due to excessive heat.

RCDs for Cables In Walls- Regs 522 – Any cable in a wall or partition, even commercial or industrial, would likely require RCD protection. Note that some types of lighting (fluorescent or LED) may cause RCDs to trip. RCD would not be required if the cabling had an earthed metal sheath such as SWA.

RCDs for Special Locations- Reg 701.411.3.3 – Cables “passing through” the zones of a Special Location are to be RCD protected.

RCDs for Generator Sets– Reg 551.7.1 – RCDs providing additional protection on circuits connecting a generator to the installation will now be required to isolate all phases including the neutral conductor.

Auxillary Circuits- Chapter 55 changes regarding auxillary control circuits.

Skilled Person Test/Insp- Part 6 Chapter 61- Change to “Skilled Person (electrically)” being competent in inspection, testing and certification.

Inspection & Testing Schedule– Part 6 Chapter 61- Schedule Of Inspections for new work has been replaced by a 2 page list and requires a Risk Assessment where RCDs are not used for sockets.

Inspection & Testing EICR– Part 6 Chapter 61- Electrical Installation Condition Repert now includes for inspection to be made in any accessible roof spaces.

Lighting General Requirements– Section 559 now only covers the general requirements for fixed lighting. Changes include protecting cable which run through luminaires against radiation and heat. Display stand lighting must have either SELV, ELV or RCD protection.

Exterior Lighting Special Location- Part 7 new sections 714 & 715 – Requirements for outside lighting and ELV installations moved here from section 559. 715 also has requirement regarding switching and control of lighting installations.

Users of the IET Wiring Regulations should be aware of the changes contained in Amendment 3 to the 17th Edition (BS 7671:2008+A3:2015). Potentially life-saving changes are proposed making this a vital update. These changes are expected to include (but are not limited to) amendments in the following areas: Consumer units (to come into effect January 2016) Wiring in escape routes Changes to earth fault loop impedances for all protective devices Updated EIC and EICR forms Changes to definitions throughout the Regulations Amendment No. 3 publishes on 5 January 2015 and comes into effect on 1 July 2015. All new installations from this point must comply with Amendment No. 3 to BS 7671:2008.

 

Bazza, it wasn't intended as an essay, lecture or anything "telling you what to do" - it was more of offering up information for constructive comments. I hadn't seen exactly what amendment 3 entailed so when I found the text I thought I'd share it to save others from having to do the same search. So it's all friendly like and let's keep it that way eh?

Indeed 30mA for final circuits only.

I think JP has the point, it would be nice to fit a RCBO but as JP says I think the unit is too old, circa 1995

 

Thanks for the suggestions guys, I like having alternative ideas to consider. My initial plan was indeed to fit a separate RCD next to the CU but then as I made enquiries, in addition as the installation is not my residence, more problems arose, basically more RCDs needed, leading to a 17thEd CU, then up popped amendment3.

Oh well seems like I need to fit two CUs (off peak), metal box (amend3) and more than likely upsize the earth lead, checking the Regs 16mm needed, bonding I think was already 10mm, the system is PME.

Thanks, it's always good to seek views of other knowledgable people, helps to justify the expense and gives a better understanding of why things need to be done in a certan way.