Exported PME to steel floodlight columns, public tennis courts

Question

Hi 
 
 We're doing an EICR at a local tennis club. It has a number of 3 phase floodlights mounted on galavanised columns illuminatimg outdoor tennis courts. 
 They are earthed via an exported PME TNCS system which was surprising because we'd imagined they would have sunk an earth rod at each column and not exported the PME. 
 
 The location is open to the public. Circuits not 30mA RCD protected foir additional protection. 
 
 I'm no 
 
 Many Thanks for your help

Sparkingchip · Accepted Answer

I should point out that the IET Guide to Highways Electrical Street Furniture was published in 2018, so predates the current edition of BS7671 and the amendments to the regulations need to be taken into consideration. 
 Also the additional earthing electrodes are &ldquo;good practice&rdquo; so may not be considered an absolute requirement.

Sparkingchip · Answer

AJJewsbury 
 the extract reads as it is good practice to install the additional earth rods for a TN-S lighting circuit being supplied from a TN-C-S supply, if and how you write a recommendation into an EICR is a matter for debate as there&rsquo;s a &ldquo;should&rdquo; and a &ldquo;good practice&rdquo; mentioned. 
 &rdquo;2.5.3 Lighting authority/asset owner private cable distribution system A lighting authority/asset owner may design and install their own cable networks but these usually consist of a separate neutral and earth (TN-S), which is connected to a PME point of supply. An earth electrode SHOULD be installed and connected to the earth terminal at the point of supply. It is GOOD PRACTICE to install and connect an earth electrode at the last or penultimate lighting column on the circuit where there are three or more columns on that circuit.&rdquo;

Exported PME to steel floodlight columns, public tennis courts

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