John was looking for advice regarding the observation coding requirements within the EICR certificate of a stair area he was testing.
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Question:
I have a query regarding a supply authority cut out fuse and some supply tails supplying a small consumer unit.
I am currently carrying out electrical testing in a tenement's stair area and was after some advice regarding the observation coding requirements within the EICR certificate. The stair area I am testing has stair lighting and a couple of other small load circuits (no more than 10A in total) which are fed from a small consumer unit, which in turn is fed from a domestic cut-out with a 100A BS1361 fuse in it. The main supply tails from the cut-out appear to be only 10 mm, possibly 16 mm.
What code should I give this on the EICR as the 100A supply authority fuse exceeds the limit of the supply tails?
Referring to Regulation 433.2.2 in BS7671, I do know that as long as the length of the tails do not exceed 3 metres and if damage to the supply tails is unlikely, and that the total load does not exceed the limit of the 10mm/16mm tails then this would possibly be okay?
The consumer unit's supply tails are less than 3 metres in length but are however situated in a common store/cupboard area where residents can gain access, so I would not say that the supply tails are totally protected from damage occurring.
What would you advise to do, as depending upon the EICR observation code I decide upon, could make the difference between a satisfactory or unsatisfactory certificate?
On another note, if the supply authority fuse is sealed, but it has a 100A label fitted on the outside of the fuse carrier, is it safe to assume that a 100A fuse is installed in the carrier? In other words, should I note 100A down for the main fuse rating in the supply characteristics and earthing arrangements section within the EICR, as there is a small possibility that a smaller fuse rating is in fact installed?
In the EICR, I could note "Limitation" in the main fuse rating details box and also write a "Note" within the observation section of the EICR, advising the client that it cannot be fully verified if the supply tails are large enough due to the main fuse rating not being fully established, but I did not know if this was okay to do either?
Answer:
The observation classification codes awarded on an Electrical Installation Condition Report should be based on the safety of those using the installation and can only be made by the inspector.
Inspection of the tails for signs of overload and damage should be taken into consideration when deciding the code.
The size of the main fuse may be recorded as a ‘LIM’ however if there were signs of overload or you consider the load of consumer unit will be greater than the current carrying capacity of the tails you may consider the size of the fuse is required to determine whether there is potential or immediate danger.
For additional guidance on Electrical Installation Condition reports please refer to Best Practice Guide No 4.
