There’s debate about exposed basic insulation in meter cupboards being satisfactory or not? Industry guidance (WRAG) say it’s satisfactory if the door’s in good shape, what’s people views on this ?
There’s debate about exposed basic insulation in meter cupboards being satisfactory or not? Industry guidance (WRAG) say it’s satisfactory if the door’s in good shape, what’s people views on this ?
There’s debate about exposed basic insulation in meter cupboards being satisfactory or not
Its a C2 from me. As is shoddy SWA termination or lack of.
SWA needs to be terminated correctly and double insulation cables SHOULD be present. Some people would say this is insulation and mechanical protection but most people call it Double Insulated. There is also a Deflecting argument of
Is a meter cabinet an electrical enclosure?
People need to look at this in 2 distinct scenarios
- Domestic Dwelling with outdoor meter cabinet, of which there are 2 variants, In Wall and On Wall
- Domestic dwelling with indoor cabinet
Other scenarios are also available like industrial or commercial but I will focus on UK domestic dwelling to make it easier
Domestic Dwelling with outdoor meter cabinet
- Risk of UV degradation
- Risk of Impact or Damage
- Risk of door being removed/severely damaged by bad weather or person making the term enclosure or cabinet compromised
- Risk of Children or Disable/Lesser-abled person or mentally impaired person making contact. Normally meter cabinet/cupboard height dependant
- Risk of unskilled person or homeowner needing access to the content of meter cabinet for legitimate reasons like read meter or Isolation in the event of a fault or fire.
- Risk of malicious intent like vandalism or common criminality
- There are other points of consideration as well so this list is not exhaustive.
Domestic dwelling with indoor cabinet
- Risk of Impact or Damage lowered but NOT eliminated. A lot of UK home have the point of original under the stairs in an average house
- Risk of Children or Disable/Lesser abled person or mentally impaired person making contact. Normally meter cabinet/cupboard height dependant
- Risk of unskilled person or homeowner needing access to the content of meter cabinet for legitimate reasons like read meter or Isolation of a fault or fire.
- There are other points of consideration as well so this list is not exhaustive.
With the above being said the outdoor scenario carries a higher inherent risk due to external influences like weather and physical damage and possibly animals. Now let’s consider the above 2 situations under normal working/operating conditions and under fault conditions. As a casing point who in the UK has see a meter cabinet with a missing front door? Or cabinets/cupboard with a pool or pooling of water inside?
Other points to consider or discuss between the community and IET, BSI and ENA (Energy Network Association) is that when SWA (Steel Wire Armour) is used into the outdoor cabinet/cupboard then there should be A Designated Entry point into the meter cabinet.
Eg Domestic Dwelling outside ON Wall meter cabinet then ONLY bottom entry is allowed in right hand corner.
Eg Domestic Dwelling outside IN Wall meter cabinet then ONLY rear entry is allowed in lower right hand corner.
Entry points need to be discussed further as the Bend Radius for SWA is quite different to Flexy Tails or Split Concentric cable.
All meter box penetrations MUST be from Below or REAR and MUST/SHALL be Gasket or INTUMESCENT SEALED. SIDE or TOP penetrations are FORBIDDEN into the meter cabinet/cupboard.
IF SWA is used in the meter cabinet/cupboard then it MUST be Terminated correctly, this may take the form of an approved glanding into a WISKA box (other brands are available). There MUST NOT be SWA single insulation on show. Non approved SWA glands are FORBIDDEN. The same applies to Split Centric cables. The Split Con MUST be terminated correctly or to manufacturers instructions.
In summation the meter cabinet SHALL have cables that ARE double insulated to provide an extra safety layer, protecting Property, People and Live Stock on the CUSTOMER SIDE with a functional and intact door. If it does not then I refer you to NASA and the document they published called
Normalization of deviance
Is a meter cabinet an electrical enclosure?
Yes it is. And for that reason, most of the other stuff you have written is irrelevant.
What happens when the door to the cabinet is missing or damaged, thus allowing access without a key or a tool?
The average Un-Skilled person would not normally enter an electrical enclosure, but they DO enter the OUTDOOR meter cupboard/cabinet for legitimate reasons like to read the meter or top up the meter on a prepay or to advise the DNO of the flashing light colour during a power-cut.
Additionally if the SWA in not Glanded correctly then moisture ingress can occur and corrode the armour of the SWA
What happens when the door to the cabinet is missing or damaged, thus allowing access without a key or a tool?
The average Un-Skilled person would not normally enter an electrical enclosure, but they DO enter the OUTDOOR meter cupboard/cabinet for legitimate reasons like to read the meter or top up the meter on a prepay or to advise the DNO of the flashing light colour during a power-cut.
Additionally if the SWA in not Glanded correctly then moisture ingress can occur and corrode the armour of the SWA
What happens when the door to the cabinet is missing or damaged
Same as if any other item of electrical apparatus is damaged... other than considering if it was suitable for the conditions in the first place, it's just life - hopefully people will be sensible enough not to use damaged equipment or keep their fingers out if it can't be de-energised, and it'll be picked up by the next inspection.
I do agree though that I don't consider a meter box to be an "electrical enclosure" in the same sense as say a joint box - on the basis that ordinary persons have good reason to access the inside of it. The problem we have is that the words in the regs seemingly don't justify that common sense (?) point of view.
- Andy.
Maybe the next amendment/edition of BS7671 can clarify that an OUTDOOR meter box/cupboard is NOT the same as a Electrical Enclosure because
The average Un-Skilled person would not normally enter an electrical enclosure, but they DO enter the OUTDOOR meter cupboard/cabinet for legitimate reasons like to read the meter or top up the meter on a prepay or to advise the DNO of the flashing light colour during a power-cut.
If the door has fallen off, or the lock is broken, then it's not an enclosure any more.
Yes, ordinary consumers can and do open meter boxes. The risk is really very low provided everything inside has basic insulation.
I do agree though that I don't consider a meter box to be an "electrical enclosure" in the same sense as say a joint box - on the basis that ordinary persons have good reason to access the inside of it. The problem we have is that the words in the regs seemingly don't justify that common sense (?) point of view.
Could BS7671 regulation 416.2.4 exclusion or note section say something like
A domestic dwelling meter cabinet is NOT considered an enclosure
Could BS7671 regulation 416.2.4 exclusion or note section say something like
A domestic dwelling meter cabinet is NOT considered an enclosure
I could, but I'd prefer a more robust approach - as it stands people can claim all sorts of things with a lock of held together by screws are acceptable as an electrical enclosure ... meter boxes are but one example - the same could be said of anything between bath panels and broom cupboards. Hence my suggestion that the definition be limited to "dedicated" electrical enclosures - i.e. things that need to be opened only for the purposed of electrical work (installation, alteration, testing etc.) and not for other purposes. Where there's a need for the unskilled/unsupervised to have access, it wouldn't count.
I wouldn't object for this "clarification" to take the form of a note, rather than the main definition, if it was easier to introduce that way,
- Andy.
Listening to a recent podcast they raised an interesting point. Have the DNS/DSO/MO re-worked their RAMS (Risk Assesment and Method Statement) as staff may now enter a meter cabinet which can NOT be isolated up stream and COULD be LESS safe due to exposed singles from the SWA.
As far as I can see, meter cabinets can almost always be isolated upstream by pulling the fuse or red link. What dangerous situation are you envisaging ?
And note that most DNOs change the cut-out without switching off the street, and that is covered by their live working methods. (see the ECS 02-0415
LV JOINTING MANUAL for example).
Mike
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