Caledonian Airport Cables
400Hz cables
400Hz cables are used for the power supply of aircraft, computer systems and radar stations. The engines of aircraft are stopped while the aircraft are stationary, in order to save fuel as well as to decrease noise level and the quantity of exhaust gas at the airport. All international airports offer a 400 Hz supply voltage for stationary aircraft. Due to safety reasons computer systems, radar equipment and communication systems of airports are connected to uninterruptable power supply plants via 400 Hz cables. With that, a total power failure is prevented, and frequency and voltage fluctuations are compensated.
Caledonian manufactures these interconnection cables for many different applications. The 400 Hz network can be designed as a central, decentralized stationary or mobile system. The 400 Hz board supply requires cables and special plugs. For distance up to 150 m a transmission voltage of 200/115 V is used. A higher voltage is chosen for larger plants with larger distances. For those plants a transformer is installed as near as possible to the aircraft (e.g at the end of the passager bridge) which reduces the supply voltage down to the board voltage of 200/115V.
Construction
The main constructional features are circular stranded (RM) or circular fine stranded (RF) conductors, PVC or XLPE insulation, with or without screen/ protection conductor, or with a special screen having a low transfer impedance; the outer sheath is mostly made of PVC, however, can also be made of PE. All cables can also be supplied in a halogen-free design. With 4 core cables voltage asymmetries and higher inductive voltage drops occur in 400 Hz networks when high ratings are transmitted. These unfavorable cable characteristics can be improved by using 7 core cables. In those cables the centre core is used as earth or neutral conductor (green-yellow or blue), and six cores with the same cross section (black with white numbers) are laid in one layer round the centre core. Two opposite-located cores are switched in parallel to one phase conductor.
Application
Caledonian airport 400 Hz cables are directly buried or laid in buildings. Halogen-free designs are only suitable for indoor installation, cables with a PE sheath only for direct burial.
Flexible 400 Hz Cables
Construction
The main constructional features are circular finely stranded (RF) conductors, EPR or thermoplastic (elastomer) insulation, with or without screen, and a sheath made of chloronated elastomer or polyurethan for a flexible installation. Flexible 400 Hz cables can also be supplied with control cores and special screening.
Application
Flexible 400 Hz cables are used: 1. between the fixed installated cable network, outside at the passager bridge or within the cladding, from the building to the front of the passenger bridge, 2. as board supply cable from the end of the passenger bridge to the aircraft. Depending on the individual location the cable is wound or reeled. If required, these cables have additional control cores for controlling the voltage level (readjustment of the supply voltage) and for the up-and-down setting of the reeling equipment, 3. as interconnection cable between the mobile power supply unit and the aircraft.
Flexible 400 Hz cables are also installed in inspection and maintenance halls.
Application for trailing cables
The lenghts used are normally 10 - 25 m long. 400 Hz trailing cables, made by Caledonian, are highly flexible and withstand extreme environmental stresses.
Their special features are
• high abrasion and tear resistance,
• resistance against oils, petrol, etc...,
• flame retardant,
• flexible at low temperatures -45°C in fixed installation -35°C in mobile installation.
Permissible bending radius (minimum rated values) • 10 x D for free movement, and • 4 x D for fixed installation.
400 Hz cables are normally connected with special plugs, which have an internationally harmonized pole configuration, and they can therefore be used with civil and military aircraft. Four poles are for the power supply , and two poles are used for the connection of control cores. Some suppliers also offer plugs with additional operating possibilities, e.g. for the on-and-off winding of trailing cables.
If you have any questions please contact us.
- Email: sales@airport-cables.com
- Website: www.airport-cables.com