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.
（2）产品规格和主要技术特性
Product Types and Main Technical Characteristics
表 2-2： JFB-口/3型电热带主要技术参数表
Table 2-2: Main Technical Parameters of JFB- 口 /3 Type Electric heat cable
型号
Type
额定 电压
Rated Voltage
（v）
额定 功率
Rated Power
（w/m）
绝缘 电阻
Insulation Resistance
（MΩ /hm）
电气 强度
Electricity Intensity
（v/min）
绝缘层 材料
Insulation Material
产品 zui高 耐温
Highest Temp- erature
（℃）
防爆 标志
Explo- sion Proof Label
zui小弯 曲半径
Min. Bending Radius
（mm）
介质zui 高维持 温度
Highest Maintenance Temperature of Media
（℃）
单电源 zui大使 用长度
Max. UseLength of Single Power
（m）
加强型
Reinforced
JFB-30/3J
380
30
≥50
2750
F46
200
ExeIIT4
普通型
Common
30 加强型
Reinforced
35
120
320
JFB-40/3J
40
100
240
JFB-50/3J
50
80
190
JFB-60/3J
60
60
160
（3）产品特点及应用场合
Product Characteristics and Applications
三相电热带除有单相电热带相同特点外，还有以下优点：
Besides the above characteristics the three phase heating cables have following advantages:
①率的三相电热带的zui大允许使用长度是单相电热带的三倍。
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.
②三相带截面大，传热导面积大，能提高传输效率。
Bigger section area of three phase heating cable can broaden heat transmitting area and thisincreases the transmitting efficiency.
三相并联带一般适用于大管径，管网系统管线和罐体的伴热保温。
Three phase parallel connection heating cables are suitable forthethermal insulation of pipes with big diameters, pipe lines in nets and tanks.
