The principle of omission in the model

Update:14 Sep 2018

Copper is the main conductor material used in wire and cable products, so the copper core code is written in T, except for bare wires and bare conductor products. Bare wire and bare conductor products, power cables, and electromagnetic wire products do not indicate large class codes. Wires and cables for electrical equipment and communication cables are not listed, but subcategories or series codes are listed.
Item 7 is a mark for various special use occasions or additional special use requirements, and is marked with a pinyin after "-". Sometimes in order to highlight the item, write this item to the front. Such as ZR- (flame retardant), NH- (refractory), WDZ- (low smoke and halogen free, corporate standards), -TH (for hot and humid areas), FY- (anti-termites, corporate standards). Power cable armor and outer sheath digital digital marking armor layer outer layer or outer sheath 0 no --- 1 interlocking armored fiber outer 2 double layer steel strip PVC outer jacket 3 thin round wire polyethylene jacket 4 thick round wire --- 5 wrinkle (rolled) steel strip --- 6 double aluminum (or aluminum alloy) belt --- 7 copper wire braid --- 8 steel wire weaving