Today's compound and extrusion process innovations can help cable manufacturers meet the unique specifications of the solar industry. Many cable manufacturers are working closely with the project designator to produce cables that meet the design requirements. In order to produce cable products that can meet the requirements of solar solar systems, their design should meet the requirements of IEC 62930:ED 1.0:2017 and BS EN 50618:2014.
When seeking to understand the specific characteristics and the focus of each standard, further consideration is the size of the cable conductor. Among them, BS EN 50618 only stipulates that the conductor size range is between 1.5 and 240m2, while the allowable range of IEC 62930 is larger, between 1.5 and 400m2. It is worth noting that even if the diameter of the cable product is large, the size of the conductor may be small because it is surrounded by the insulation layer, cushion layer and steel wire armor. Therefore, deciding which standard cable products should be tested should not be based solely on conductor size.
The main difference between the standards is the materials allowed to be tested. For example, BS EN 50618 only allows the testing of cable products made with LSHF materials. These types of cable products emit lower smoke and corrosive gases when they encounter a fire. They are usually designated for public buildings because they can reduce the risk to public safety. In contrast, IEC 62930 allows testing of materials with or without LSHF, including pvc cable products. When this material burns, it will produce dense smoke and toxic fumes. PVC or modified PVC is more suitable for customer requirements. For example, PVC cable products may be more suitable for transporting electricity from solar panels to water treatment facilities because they have higher chemical resistance than LSHF products.
As part of IEC 62930 and BS EN 50618, heat resistance testing is mandatory. The test is designed to determine the service life of the cable, including testing any solarcable product at a temperature of up to 120°C for 20,000 hours to simulate the performance of the product in operation. When these standards were first formulated, the thermal endurance test caused some controversy, because the main measure was to prove how long the cable would run before reaching the specified threshold; all these tests were carried out under controlled conditions. Since many solar cable products are installed under extreme conditions, the results of this test may not be as decisive as more mature tests (such as the thermal pressure test used to check whether the sheath and insulation materials can withstand pressure at high temperatures). Nevertheless, submitting cable products for heat resistance testing can further help prove the quality of the cable.
Although cable products can successfully pass the heat resistance test, consideration should also be given to how other characteristics will be affected by their operating conditions. For example, solar panels are usually installed in coastal or desert areas, where the temperature may drop rapidly, which may cause the cable to rupture or bend because the temperature drops to the design operating temperature value of these cable products. If the cable products are produced using inferior materials, they may absorb a lot of water and reduce the performance of the cable products by reducing the current that the cable products can carry. These examples show the need for extensive performance testing of solar cables to verify the quality and applicability of installation under specified conditions.
