DSTA stands for double steel tape amoured which means stainless steel tape. This is a metal armor used to protect the inner layers of underground cables. This metal armor layer is clearly specified in the standards for underground electric cables such as low voltage underground cables (TCVN 5935-1: 2013), medium voltage underground cables (TCVN 5935-2: 2013).
The specification of the bandage construction is as follows : The tape armor shall be spirally wound in two layers so that the outer band is approximately centered over the gap of the inner band. The clearance between adjacent loops of each ribbon shall not exceed 50% of the width of the ribbon.
Also according to the metal armor regulations, in addition to being able to make armor out of tape, electrical cable manufacturers can also produce round / flat wire to make metal armor.
Learn about underground cables
Underground power cables are manufactured to transmit electricity to the power grid system and are laid underground. Because of this requirement, underground cables are regulated and manufactured according to very strict standards.
Structure of medium voltage underground cable SUNWON
SUNWON 1 core conductor medium voltage underground cable has the structure as shown in the picture, the layers include:
- Conductor : Aluminum copper conductor consisting of many aluminum filaments, electrical engineering circular copper twisted and pressed together;
- Conductor Screen: The conductor screen shall be of non-metallic material and shall be of extruded semiconductor compound, which may be placed on top of a semiconductor ribbon. The extruded semiconductor compound shall be firmly bonded to the insulation.
- Insulation layer ;
- Insulating screen: The insulating screen shall consist of a non-metallic semiconductor layer combined with a metallic layer. The non-metallic layer shall be extruded directly onto the insulation of each core and made of an adherent or peelable semiconductor compound.
- Metallic Screen: The metal screen shall be one or more strips of tape, or a woven mesh or a layer of concentric wire, or a combination of the wires and the tape(s).
- Semiconductor layer ;
- Metal armor : The types of armor covered by this standard are as follows: a) flat wire armor; b) armor of round wire; c) double tape armor.
- Round wire or flat wire shall be galvanized steel, copper or tin coated copper, aluminum or aluminum alloy.
- The ribbon must be steel, galvanized steel, aluminum or aluminum alloy. Steel strip shall be hot-rolled or cold-rolled of commercial quality.
- Cover layer .
Structure of low voltage underground cable SUNWON
SUNWON low-voltage underground cable consists of underground aluminum cable and underground copper cable, structured from 1 to 4 conductors and includes the following layers:
- The conductor core consists of many copper and aluminum wires, concentrically twisted and pressed together;
- XLPE Insulation Layer ;
- PP filler ;
- Semiconductor PVC layer ;
- Metal armor : stainless steel cuffs;
- The outer shell is made of PVC plastic.
The DSTA stainless steel cuff is a mandatory requirement in the production of SUNWON underground cables. In addition to DSTA, the customer can request the production of other similar metallic armor such as round/flat wire in copper, aluminum/aluminum alloy or galvanized steel.
The requirements for metal armor with round / flat wire are as follows: The armor made of wire must be closed, that is, the leaf has the smallest gap between adjacent wires. Galvanized steel cuffs with a minimum nominal thickness of 0.3 mm may be used spirally wound over the armor with flat wire and over the armor with round wire, if necessary.
