A 4 storey office block with it's own transformer on a TNCS system requires 20 EVC points located in a rear goods yard. Each are 11kw 3 phase so 16A TP apiece via 16A Type A RCBOs. Each EVC will be independanly spiked using either a traditional earth spike or a Condudisc to make them TT. All SWAs will terminate at an adaptable box in LV Switchroom mounted below D/Board thus keeping all EVC earths seperate to that of the TNCS. The plan is to install a metal construction solar panel canopy over the 20 parking bays. Presumably this will need earthing but to which system? The legs of the canopy are metal and may fall within 2m of a number of EVCs. I'm guessing bond them to the local TT Charging point? The other issue is the solar on the canopy roof which is importing back into the buildings LV TNCS System currently serving the building and the question is - will this need earth seperation and to what system. Any feedback is greatly appreciated.
Even if you TT the whole installation or just TT the EV charging socket the problem is getting the TT electrode away far enough from any under ground metallic pipes or metal work that is connected to the PME earthing system or connected to your neighbors PME earthing system.
I feel sure that the AMD 1 722 published on Monday may provide some useful guidance but we will have to wait until then. 2 big sleeps before we find out!
Of course if you came to the Elex show this week you will be all clued up on 722. If not come along to Manchester Elex to see the the 2 No excellent presentations from the IET.
Even if you TT the whole installation or just TT the EV charging socket the problem is getting the TT electrode away far enough from any under ground metallic pipes or metal work that is connected to the PME earthing system or connected to your neighbors PME earthing system.
I feel sure that the AMD 1 722 published on Monday may provide some useful guidance but we will have to wait until then. 2 big sleeps before we find out!
Of course if you came to the Elex show this week you will be all clued up on 722. If not come along to Manchester Elex to see the the 2 No excellent presentations from the IET.
