LSZH-Low Smoke Zero Halogen
The minimum bending radius of cable is that radius below which the cables should never be bent. The minimum bending radius depends upon the type, voltage grade and construction of the cable.
Type tests are the tests made before supplying, on a general commercial basis, a type of cable in order to demonstrate satisfactory performance characteristics to meet the intended application. These tests are of such nature that after they have been made, they need not be repeated, unless changes are made in cable materials or design or manufacturing process which might change the performance characteristics.
When type tests have been successfully performed on a type of cable with a specific conductor cross sectional area and rated voltage, the type approval is accepted as valid for cables of the same type with other conductor cross sectional areas and/or rated voltages subject to satisfaction of conditions set out in the IEC specification.
Discharges in a cable are caused by the breakdown of the gas contained within voids in the insulation. These tiny electrical discharges release electrical charge, which can be detected using highly sensitive equipment. The voltage at which the breakdown first occurs is known as the discharge inception voltage and the charge is measured in picoCoulombs (pC). These discharges can lead to cable failure in service so it is vital to detect them during routine test of each cable length.
Specifications for MV polymeric cable all require measurement of partial discharge and define the maximum level of discharge acceptable at particular test voltages. However, any discharges detected within a cable should be identified and eliminated even if found to be below the specification limit.
Different types of outer sheath and their applications are as below.
|Material||Key properties||Recommended for|
|PE||High mechanical strength||Direct burial, duct installation|
|PVC||Flexibility & flame retardance||General purpose|
|LSZH||Zero halogen , low smoke||Mass transit system, high rise building, public areas & confined locations.|
Installation and commissioning tests for any cables are not done by Jiangnan Cable.