Protect your Solar PV Investment from Lightning Strike

Protect Your Solar PV Inversment Against Lightning Strike

A P.V array is at risk from a lightning strike, therefore adequate earthling/lightning system must be installed to reduce the risk of Injury to persons or damage to the array and inverter.

It`s not just your Personal Interest, The Lightning Strike Protection for Solar PV Systems in Ireland also Stated in the RECI ETCI Regulations.

The array will require protection from the lightning if it is:

  • Mounted high on a structure
  • Installed in an open area
  • Covers a large area

 

Purpose of Earthing the Solar PV Array

Earthing the array frame is intended to remove the risk of electric shock and it also provides a degree of protection from lightning surges.
The inverter should be treated as standard fixed A/C electrical apparatus and earthed as per ETCI rules.

 

Array Protective Conductors

Protective equipotential conductors shall be run parallel to and in close contact as is possible with the D/C cables, D/C accessories according to E.T.C.I-715.544.01:

 

 

A Surge protection device (SPD) must be installed for the protection of the low voltage distribution system A/C and D/C.

If LPS is required then the installation of SPD is mandatory and it must comply with International Standard regarding protection against lightning strike IEC 62305.

 

SaveMeMoney Earth each of our Solar PV Installation according to our Internal Code of Practice.

 

 

Lighting Protection System (L.P.S)

Internal Lightning Strike Protection on Solar PV String

 

A lightning protection system is installed on a structure for protection against a lightning strike

 

 

 

There are two types of lightning protection systems:

  • External lightning protection (Protect P.V system and People)
  • Internal Protection / Surge Protection system (Protect P.V system, Connected Devices, and People)

 

 

External Lightning Protection

  • External lightning protection is achieved by installing a lightning conductor that will attract lightning and allow a low resistance path to ground.
  • This lightning protection system will protect the building and its occupants from a direct lightning strike.

 

Internal Protection / Surge Protection

  • Internal protection/surge protection is achieved by installing A/C and D/C surge protectors.
  • These are wired from both live and neutral A/C, and positive and negative D/C to the earth.
  • This system will protect the PV system, the building and its occupants from high voltages or surges induced by a lightning strike.

 

 

 

In what circumstances needs to be Earth the Solar PV Array?

  • If the inverter does not contain an isolation transformer between its A/C and D/C parts.
  • If any conductive part of the array and its mounting frame is mounted within an equipotential zone, then ETCI rules require that it’s bonded to the main earth terminal to ensure accessible parts within the zone remain at the same potential.
  • If there is a risk of the array frame reaching A/C mains potential.
  • If earthing is required, the array frame must be bonded to the main earth terminal.
  • Continuity of all conductive parts of the frame verified.

 

 

If the premises or area where the array is mounted (such as house and/or Factory) contains an L.P.S, the array must be connected to it, and earth continuity test carried out to verify a low resistance path to earth.

Supplementary bonding may also be required between parts of the PV array frame.