1. Variety and model of branch cable
1. YJV copper core XLPE insulated and PVC sheathed power cable;
2. ZR-YJV copper core XLPE insulated PVC sheathed flame retardant power cable;
3. NH-YJV copper core XLPE insulated PVC sheathed fire-resistant power cable;
4. ZR-YJV copper core XLPE insulated PVC power cable;
5. VV copper core polyethylene insulated and PVC sheathed power cable;
6. ZR-VV copper core PE insulated and PVC sheathed flame-retardant power cable;
7. NH-VV copper core polyethylene insulated PVC sheathed fire-resistant power cable;
Note: ①The rated voltage (U0/U) is 0.6/1KV.
②The trunk and branch cables use black jackets.
③ If the branch cable is required to use color code (yellow, red, green, light blue, yellow/green) BV-500 wire, it should be specified when ordering.
2. The production process, process and technical requirements of prefabricated branch cables
Due to the occupation of prefabricated branch cables, large equipment investment, complex technology, and high technical requirements, only a few domestic manufacturers started trial production in the mid to late 1990s. So far, several manufacturers' products have been officially launched on the market in batches.
Prefabricated branch cables, as the name suggests, are the main and branch cable types, specifications, cross-sections, lengths, and branch positions required by the cable users. A series of special production equipment in the factory are completed on the assembly line. Branch cable.
The following briefly introduces the corresponding technical indicators and requirements of each part.
1) Cable inspection technical requirements:
a. The main and sub-cables should meet the relevant technical indicators and requirements of GB/T5023.; GB/T12706; and IEC60227.
b. The main and branch cables should meet the specifications, models and cross-section requirements specified by the user.
2) The cable hanger is used as a lifting device for the vertical installation and arrangement of the prefabricated branch cable. It is an accessory for the prefabricated branch cable. When the prefabricated branch cable is arranged horizontally, this accessory is not required.
skills requirement:
a. Withstand AC.3500V for 5min without breakdown; insulation resistance ≥200MΩ. b. The prefabricated branch cable will not fall off for 24 hours under the weight of twice the weight of the prefabricated branch cable. After the prefabricated branch cable is installed and fixed, the lifting head no longer bears gravity.
3) Technical requirements for stripping the outer sheath and inner insulation of main and sub-cables:
a. Confirm the length and size specified by the user;
b. Cut and strip the outer sheath and inner insulation of the main and sub-cables. The cuts should be neat and seldom damage the conductor material of the cable.
4) Technical requirements for press forming of branch joints:
a. The joints should meet the technical standard requirements;
b. After crimping, the branch joints should have sufficient crimping force and contact area to ensure that the contact resistance is about the equivalent length of the conductor;
C. Do not damage the conductor materials of the main and sub-cables during the crimping process;
5) Technical requirements for injection molding of branch joints:
a. The insulating material used for injection molding should be the same type of insulating material as the inner insulating or outer sheath of the main and sub-cables;
b. Do not cause any damage to the original inner insulation and outer sheath of the main and branch cables during the injection molding process;
c. Ensure the air-tightness and water-tightness after the injection molding material and the outer sheath of the main and sub-cables are effectively glued;
d. After the branch conjoined body is injection-molded, the breakdown voltage is AC.3500V for 5min without breakdown; the insulation resistance is ≥200MΩ.
6) Finished product inspection of prefabricated branch cables
a. Visual inspection;
b. Continuity inspection of main and branch cables;
c. Withstand voltage inspection;
d. Insulation resistance inspection.
7) Finished packaging of prefabricated branch cables
When prefabricated branch cables are packaged, each cable end is sealed with a cable cap, and then wound on a cable reel or in a bundle, and is packaged in a suitable way that will not damage the cable during transportation.