Cable characteristics for photovoltaic applications

Thursday, Jan 26, 2012

Topsolar cables, from Top Cable, become the best alternative when performing photovoltaic installations.

Connection of panels to the Low Voltage network in continuous current

The TOPSOLAR (PV) cable has been specifically designed to withstand the most demanding conditions between the panels and LV network in continuous current from a solar photovoltaic installation.

Its excellent proprieties make it the best cable for all LV installations:

• It has a useful life of 30 years at 90 ºC, being able to withstand up to 120°C continuously. Temperatures higher than 90 ºC are common in installations on rooftops. Normal cables with reticulated polyethylene or EPR insulation are designed for a maximum conductor temperature of 90 ºC and noticeably colder surroundings. It is demonstrated in tests that the TOPSOLAR (PV) cable shows high resistance to weather corrosion, abrasion, and chemical agents.

• Its allowable current is superior in identical sections to conventional cables. High-quality ethylene-propylene insulation of TOPSOLAR (PV) cables allows the conductor’s temperature to reach 120ºC, which implies important increases in allowable currents with regards to similar sections of conventional cables.

• It is halogen-free, fire-retardant and has reduced the emission of opaque fumes. It surpasses the tests for flame-retardants, fire-retardants, low emission of opaque fumes and low emission of toxic and corrosive gases, which on top of decreasing the collateral effects of fires on people, also protects the solar installations’ valuable electronic equipment due to its high fireproofing and the low corrosiveness of emitted gases.  

• It is fit for mobile services. The use of followers is frequent to get the most out of solar radiation. It should not be forgotten that in these cases the connection cables between mobile structures and the fixed parts are subject to movement, for which conventional cables are not suitable. The TOPSOLAR (PV) line demonstrates good mechanical properties even at low temperatures.

• It is more convenient to install due to its extraordinary flexibility and reduced diameter. The cable is made of a flexible class 5 tin-plated copper conductor, high-quality insulation of ethylene propylene and an outer sheath of ethylene vinyl acetate (EVA). Its reduced outer diameter makes the cable more manageable and takes up less space in the wiring.

Cables for the Low Voltage network in alternate current

At the inverter’s output begins the LV network in alternate current, which ends in the connection point to the LV network or even the transformer, in the case of connecting to the MT network. In solar parks, this LV channelling in alternate current tends to be buried pipes. Moreover, in this type of application, the designers should evaluate the possible presence of rodents in any part of the installation. In this case the use of armoured cables should be considered, like those of the TOPSOLAR XZ1FA3Z-K type.

Cables for the Medium Voltage network

Top Cable offers two cable families:

• those insulated in reticulated polyethylene (XLPE)

• those insulated with ethylene propylene (HEPR)

Both in voltages up to 30 kV.

The X-VOLT range has its cold-shrinkable outer semiconductive layer, a quality highly valued by the installers, given that its easy removal is a critical factor when correctly preparing the cable tips for the making of joints and outlets, furthermore constituting a notable saving of time.
 
The X-VOLT RHZ1 cables, insulated in XLPE, are characterized by a good dielectric rigidity, low loss factor and high insulation resistance.

The X-VOLT HEPRZ1 cables, insulated with HEPR, can withstand temperatures of 105 ºC in continuous operation, demonstrating very good resistance to thermal aging and partial discharge.

In both cases, the cables can include elements sealed in the shield that impede longitudinal water propagation in case of breakdown of the sheath and/or elements for the longitudinal sealing of the conductor.

For more information visit www.topcable.com

Source: Top Cable