Dexmet Multipath Resistors - Ratings and Ranges

Two basic designs are used; The flat element (Figure 1A) and the girder element (Figure 1B). The choice of element design is dictated by current, space, resistance, allowable temperature rise and cooling requirements. Experience has shown that a six mesh unit (6-3/4”) is the maximum flat element design with mechanical integrity. Current application requiring wider strips are formed into girder elements. An example of the range of rating variations is shown in Figure 2. Current ratings in this chart assume a convection cooled atmosphere with an ambient temperature rise of 350 • C.

The expanded length of this strip dictates its resistance value in relation to width, described as “number of meshes”. “Number of meshes wide” is a controlling factor for current rating within a specific metal thickness and strand configuration. Please also note that the “three-mesh-wide” strip can carry 35 amperes, 62 amperes, or 91 amperes by varying material thickness and strand width. Of course, as the current rating increases, the resistance rating would decrease. Current resistance combinations anywhere in between those detailed in this chart are also available.