Commercial Installations

For installations with a three phase PME supply matt:e connection centres that incorporate the Patent Pending OPEN should be used. The device is able to detect load imbalances under all conditions including open PEN on three-phase infrastructures and safely isolates the incoming supply or individual loads. This helps prevent the risk of electric shock if dangerous touch voltages above 70V occur in line with BS:7671 2018: amendment 1: 2020

Regulation 722.411.4.1

  • (iii) Protection of electric shock is provided by a device which electrically disconnects the vehicle from the live conductors of the supply and from protective earth in accordance with Regulation 543.3.3.101 (ii) within 5 s in the event of the voltage between the circuit protective conductor and Earth exceeding 70 V rms due to an open –circuit fault in the PEN conductor of the low voltage network. The device need not operate if the voltage exceeds 70 V rms for less than 4 s. The device shall provide isolation and be selected in accordance with table 537.4. Closing or resetting the device shall be possible only if the voltage between the circuit protective conductor and Earth does not exceed 70 V rms. Equivalent means of functionality could be provided within the car charging equipment.

Annex 722, item A 722.4 gives guidance on voltage monitoring device described in Regulation 722.411.4.1 (iii)  and describes a device that measures the voltage between the circuit protective conductor of the electric vehicle charging equipment and Earth. During a PEN failure in the supply network, the neutral of a TN-C-S supply is no longer considered to be reliably connected to Earth, and a device that measures the voltages between the following points will fail to provide equivalent safety to the device described in Regulation 722.411.4 (iii):

(i)The circuit protective conductor and neutral

(ii)The circuit protective conductor and the consumers main earthing terminal

Suitable arrangements include measurement of the voltage between either:

(a)The circuit protective conductor and a suitable measurement earth electrode, or

(b)The circuit protective conductor and a reference point derived from the line conductors of a three-phase system, provided that suitable precautions are also taken to disconnect the device when the supply to one or more-line conductors is interrupted.

 

 

The future is safe, the future is OPEN

Key Features

  • Standardises installation
  • No more scanning for buried services
  • Minimises civil works
  • Prevents danger posed by driving Earth electrodes into the ground
  • Allows charge points to be mounted directly onto metal-clad structures
  • Units available to match all common charge points up to 80amp TPN
  • Safer earth connection as connected directly onto PME supply
  • Guarantee that the earth resistances values are maintained all year round
  • Designed and manufactured in Great Britain