1）產品結構與工作原理 
 Product Structure and Working Principle 
 
 

 
   　 三根平行的絕緣銅線為電源母線，在內護套絕緣層外纏繞電熱絲，并將該電熱絲每隔一定距離分別依次與三根電源母線循環(huán)連接，在每二相間形成連續(xù)并聯(lián)電阻。當母線通以三相電后，各并聯(lián)電阻同時發(fā)熱，因而形成一條連續(xù)的加熱帶。
Three parallel insulation copper wires form power generatrix. Electric heating threads are wound around the inner jacket insulation layer ln every certain distance, the heating thread is welded in turn to the three power generatrix circularly. This makes every 2 phases into acontinuous parallel connection resistance. When the generatrix is connected to 3 -phase power supply, the every parallel resistance heats at the same time This makes a continuous heating belt.
 　　Product Types and Main Technical Characteristics

表 2-2： JFB-口/3型電熱帶主要技術參數(shù)表 
Table 2-2: Main Technical Parameters of JFB- 口 /3 Type Electric heat cable
 

 （3）產品特點及應用場合
Product Characteristics and Applications

三相電熱帶除有單相電熱帶相同特點外，還有以下優(yōu)點：
Besides the above characteristics the three phase heating cables have following advantages: 
①率的三相電熱帶的zui大允許使用長度是單相電熱帶的三倍。
The most tolerable length of the three-phase heat cable is three times longer than the length of the single-phase heating cable of the same wattage.
②三相帶截面大，傳熱導面積大，能提高傳輸效率。
Bigger section area of three phase heating cable can broaden heat transmitting area and thisincreases the transmitting efficiency.
 
三相并聯(lián)帶一般適用于大管徑，管網系統(tǒng)管線和罐體的伴熱保溫。
Three phase parallel connection heating cables are suitable forthethermal insulation of pipes with big diameters, pipe lines in nets and tanks.