NRG Product Manual
Hybrid XT Anemometer
HybridXT_Anemometer_Manual
Rev. 15
[email protected] | Page 19
02 January 2020
4 Use shielded or “screened” cable with high shield coverage for sensor cabling. We recommend
bonding the cable shield to the grounding system at both ends- at the sensor, and at the
connection to the turbine control system- to provide maximum protection from LEMP. However,
see note 6 about preventing ground loops. NRG Systems supplied cables provide a shield at the
sensor end. If your LPS design does not use this shield drain, trim it off to prevent short circuits.
5 Run the sensor cabling in metallic raceway or conduit. Bond the raceway or conduit to the LPS at
both ends. This provides protection for the sensor and cabling against EMI and LEMP.
Recommendations 6 and 7 relate to ground loops and over-voltage protection.
6 Provide sufficient bonding to prevent ground loop currents in the shields and raceways.
Whenever possible, it is better to resolve the underlying grounding problems, rather than leaving
the shield unconnected to prevent ground loop current flow.
7 Since the sensor's electronics and cabling are in LPZ 1, isolation and or over-voltage protection
should be provided at the interface between the sensor cabling and turbine control system to
provide LPZ 2 or better protection for the controller.
Reference:
1.
IEC TR 61400-24: 2002: Wind Turbine Generator Systems- Part 24: Lightning Protection.
2.
IEC 61312-1: 1995: Protection against Lightning Electromagnetic Impulse- Part 1: General Principles
