The last remaining domestic circuits without RCD protection.

When is a luminaire not a luminaire? (This is a serious question, not a joke!)

The definition of a luminaire (taken from the IEC website) is: An apparatus which distributes, filters or transforms the light transmitted from one or more lamps and which includes, except the lamps themselves, all the parts necessary for fixing and protecting the lamps and, where necessary, circuit auxiliaries together with the means for connecting them to the electric supply. Depending on your interpretation of this, a pendant light fitting may (or may not) be a luminaire.

BS 7671's definition is almost identical. It's a good question - to my mind a simple lampholder doesn't distribute, filter or transform light - so would initially seem not to be covered by the definition - but then the same could perhaps be said for a 'well glass' fitting with clear smooth glass (the glass just lets the light straight through unchanged - without altering its distribution, or filtering it or otherwise transforming it in any practical way). The more I read it, the less illuminated I feel.


Similarly, the usage of the term 'mechanical maintenance' seems to be drifting away from its original definition (presuming it wasn't the intention to prohibit switching off using ordinary light switches before changing a lamp - now the 18th practically demands full isolation for mechanical maintenance).


  - Andy.

When is a luminaire not a luminaire? (This is a serious question, not a joke!)

The definition of a luminaire (taken from the IEC website) is: An apparatus which distributes, filters or transforms the light transmitted from one or more lamps and which includes, except the lamps themselves, all the parts necessary for fixing and protecting the lamps and, where necessary, circuit auxiliaries together with the means for connecting them to the electric supply. Depending on your interpretation of this, a pendant light fitting may (or may not) be a luminaire.

BS 7671's definition is almost identical. It's a good question - to my mind a simple lampholder doesn't distribute, filter or transform light - so would initially seem not to be covered by the definition - but then the same could perhaps be said for a 'well glass' fitting with clear smooth glass (the glass just lets the light straight through unchanged - without altering its distribution, or filtering it or otherwise transforming it in any practical way). The more I read it, the less illuminated I feel.


Similarly, the usage of the term 'mechanical maintenance' seems to be drifting away from its original definition (presuming it wasn't the intention to prohibit switching off using ordinary light switches before changing a lamp - now the 18th practically demands full isolation for mechanical maintenance).


  - Andy.