Earthing CAT6 SWA cable connecting EVSE.

Question

Armoured External Cat6 UTP Solid Cable (Price Per Metre) | Cat6 Cable (cablemonkey.co.uk) 
 When running CAT6 SWA to Electric Vehicle Supply Equipment to provide an internet connect to allow the equipment to be activated remotely using an App or by the electric supplier if the consumer has signed up for a tariff that allows the electric supplier to select the precise charging times should the SWA armour always be earthed at one end only or should it mirror the connection of the CPC or armour of the EVSE supply circuit?

gkenyon · Accepted Answer

The cable must not be earthed at both ends, if the charging point has a different earthing arrangement due to PME (own TT for example) ... otherwise, you defeat the object of having TT to get round the PME issue. 
 Otherwise, earthing at both ends is usually better from an EMC point of view, but you will need to consider: 
 
 the effect of "defeating" an open-PEN detection device if one is fitted. 
 current-carrying capacity of the armour, as it will share any fault current of the mains power cable. An adiabatic check may be necessary. dependent on current sharing. 
 
 In all cases, SPDs may be necessary for the data cable in accordance with BS EN 50174-3, and may be required for the charging point itself, because of LPZ concept. SPDs almost certainly necessary for both power and data if the charging point has its own TT earthing arrangement.

Earthing CAT6 SWA cable connecting EVSE.

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