Mixed manufacturer devices in din rail enclosure.What code?

Sparkingchip:


Are you going beyond the requirements of a fixed installation EICR and moving into machine and appliance regulations?


Andy Betteridge 


 

This is a great question, because when you talk to some people in the industry about the extent of an EICR (or even initial verification), they believe that you will, say, do an earth continuity test to an appliance connected to a fixed connection unit - yet the appliance, and where applicable its pre-fitted connecting cable, are outside the scope of BS 7671.


Regardless of the technicalities in standards regarding the rights and wrongs of this belief, in my experience those carrying out initial verification and EICRs go up to the point of connection of an appliance or machinery, and no further - the usual exception being lighting where the fixed wiring is brought into the luminaire.


Why is this a good thing to have a discussion about?


Well, the person ordering an EICR might be under the impression that they've had the earthing of their fixed appliances checked ... when in fact it's been omitted, often with very good reason ... for example with appliances having a mix of means of protection against electric shock:

• just because you can't get earth continuity to an accessible metal part doesn't mean it's a "fail", because that part might not be an exposed-conductive-part in that particular appliance, and without dismantling it you can't tell

• on the other hand, saying "pass" because you got a reading at one accessible conductive part doesn't mean the whole appliance is correctly earthed, and you'd be implying the appliance was OK when it wasn't !

So, as an example, what happens when the landlord has his regular check, but there's a problem with the protective earthing in an electric wall-mounted radiator or towel-rail, and someone gets a shock?

Sparkingchip:


Are you going beyond the requirements of a fixed installation EICR and moving into machine and appliance regulations?


Andy Betteridge 


 

This is a great question, because when you talk to some people in the industry about the extent of an EICR (or even initial verification), they believe that you will, say, do an earth continuity test to an appliance connected to a fixed connection unit - yet the appliance, and where applicable its pre-fitted connecting cable, are outside the scope of BS 7671.


Regardless of the technicalities in standards regarding the rights and wrongs of this belief, in my experience those carrying out initial verification and EICRs go up to the point of connection of an appliance or machinery, and no further - the usual exception being lighting where the fixed wiring is brought into the luminaire.


Why is this a good thing to have a discussion about?


Well, the person ordering an EICR might be under the impression that they've had the earthing of their fixed appliances checked ... when in fact it's been omitted, often with very good reason ... for example with appliances having a mix of means of protection against electric shock:

• just because you can't get earth continuity to an accessible metal part doesn't mean it's a "fail", because that part might not be an exposed-conductive-part in that particular appliance, and without dismantling it you can't tell

• on the other hand, saying "pass" because you got a reading at one accessible conductive part doesn't mean the whole appliance is correctly earthed, and you'd be implying the appliance was OK when it wasn't !

So, as an example, what happens when the landlord has his regular check, but there's a problem with the protective earthing in an electric wall-mounted radiator or towel-rail, and someone gets a shock?