FSC Origin
Posted: Sat Dec 04, 2021 11:24 am
Just wanting some thoughts on the origin of the FSC for EVSE. The first quote below is from the addendum to the work safe guidelines and the second from AS/NZS 3000:2018.
“3. Where an EVSE is installed at a residential installation, the charging final subcircuit shall be protected by a type B RcD and the subcircuit shall originate from a MEN switchboard.”
“7.9.2 …The supply shall NOT be obtained from a switchboard that is supplied by a PEN neutral conductor in the submain using the outbuilding provisions of Clause 5.5.3.1. NOTE: The use of the PEN neutral and earth connections required for electric vehicle charging system prevents the correct earthing connections from being provided for the electric vehicle charging system earthing failure detection system.”
So the work safe guidelines recommended the FSC coming from an MEN switchboard, but 3000:2018 requires that it is not supplied by a sub board with a PEN.
Is there a reason that EVSE should be supplied by an MEN board or would it be fine to supply from a sub board with a submain PEC? And if it should be supplied by an MEN board then would all EVSE FSCs need to be supplied from the main switchboard?
I realise these documents are not mandated through the regulations, but would still need to base electrically safe reasoning off of something.
“3. Where an EVSE is installed at a residential installation, the charging final subcircuit shall be protected by a type B RcD and the subcircuit shall originate from a MEN switchboard.”
“7.9.2 …The supply shall NOT be obtained from a switchboard that is supplied by a PEN neutral conductor in the submain using the outbuilding provisions of Clause 5.5.3.1. NOTE: The use of the PEN neutral and earth connections required for electric vehicle charging system prevents the correct earthing connections from being provided for the electric vehicle charging system earthing failure detection system.”
So the work safe guidelines recommended the FSC coming from an MEN switchboard, but 3000:2018 requires that it is not supplied by a sub board with a PEN.
Is there a reason that EVSE should be supplied by an MEN board or would it be fine to supply from a sub board with a submain PEC? And if it should be supplied by an MEN board then would all EVSE FSCs need to be supplied from the main switchboard?
I realise these documents are not mandated through the regulations, but would still need to base electrically safe reasoning off of something.