TECHNICAL NOTE : Installation of obstruction lights powered with solar kit on towers supporting high voltage cables

1 - MAIN CONFIGURATIONS OF OBSTRUCTION LIGHTS USED IN TRANSMISSION LINES

As per ICAO annex 14 chapter 6 recommendations, the obstruction lights for transmission lines are the same than for standalone pylons but with a solar kit as per 1.1 and 1.2 :

1.1 Night only operation with low intensity type A or B only (red fixed lights with 10 or 32 candelas minimum) or combination of red medium and low intensity both type B, this is the case when the towers is without red and white marks

Le balisage nocturne des pylônes est assuré par 2 catégories de feux

- for tower below 45 meters, low intensity type A NAVILITE-SOL that are red fixed light with not less than 10 candelas between 2° and 10° above the horizon

The size of the solar kit depends the local sunshine and min/max temperature for the choice of the batteries, OBSTA provide a special study to optimize the size of the solar kit based on exact latitude/longitude or area (state, country or continent)

Exemple of size of solar kit in France with low intensity type A where 3 main area have been defined:

- for towers higher than 45 meters, medium intensity type B OFC-RI-SOL (red flashing with 2000 candelas in a vertical beam of 3° on the horizon)

Since end of 2020, the FAA requires red obstruction lights to be compatible with NGV (Night Vision Goggles). Since that date, all of red or dual color obstruction light medium and high intensity include by default infrared leds while it was on option before that date. However it remains an option for the low intensity: For low intensity, the NAVILITE-IR-F-048 comply with this standard and used in most European countries

1.1.1 Installation of the solar kit on the tower

Because red medium and/or low intensity do have limited power consumption, the weight of the solar kit is limited (except in Nordic countries) and may not need special platform. The solar kit is installed on the frame of the tower oriented to the South

1.1.2 Typical installation with gel batteries (except Nordic countries)

• tower below 45 meters

• tower above 45 meters and up to 105 meters

• for higher tower, additional lights to be installled every 52 meters max

1.2 Day and night obstruction lights (in absence of red and white paint for exemple)

1.2.1 Installation

Because dual color medium intensity does have a much higher power consumption OFI360-RW-048 and so the weight of batteries is important, a duckboard installed a few meters above the ground should be considered, solar panels could be installed on the frame of the tower at the same level or higher depending on the sunshine and latitude

1.2.2 Typical configuration

• if tower is 45 meters high, dual color medium intensity (white mode only activated, day only) and 1-2 low intensity (night only) both at the top.
• if tower is higher than 45 meters and below 105 meters high, dual color medium intensity (day & night operation) at the top and 2 low intensity (night only) at mid level:

In case of a group of pylons, the flashes and day/night are synchronized through the GPS of the dual color lights or external at the bottom; It is also possible to use an external photocell for the change of the day/night switch however the change of intensity and white/red color between day and night may not be synchronized between the towers.

2 - MAINTENANCE

In presence of IOT controller, the maintenance is required only when it is necessary... If required, the maintenance required : • the site to be secured • the staff to be trained on elevated works and high voltage
• The installations vary depending on the geometry of the towers, their height and the type of obstruction lights (day and/or night) and the batteries (solar gel, crystal, or LTO for Nordic countries etc). • the staff must includes at least on person with electrical habilitation for low voltage work. In all case a yearly visit must to done for a visual inspection (waterproofness, corrosion, check of the brackets of the equipment etc...).

ANNEXE : PHOTOS D'INSTALLATION

France : day marking (medium intensity type A white flashing) and at night (low intensity red fixed)	Installation in mountain : red light only	Dual color medium intensity at the top with low intensity type B at mid level	Medium intensity type A during day time only and low intensity at night only
Low intensity (red fixed) with infrared (blinking) in Switzerland and operating at night only	NAVILITE with infrared and warning spheres on OPGW operating at night only	Sweden: NAVILITE with infrared	Sweden: NAVILITE with infrared