The modular nature of Duraline's distribution systems for electrical resistance heat treating applications provides the maximum in flexibility of choice and economy in use. While some assemblies can be combined or intermixed to create new systems, certain parameters must be observed to ensure that a functionally safe, economical, and efficient system is obtained.

• The U.S. Navy 3 and 4 wire system configurations are not variable from the Bureau of Ships standard
• Commercial percentage timer systems may be specified with differing output receptacles and power streamer plugs for multiple applications or dedicated system at one site.
• Input cables may be furnished up to 100 feet long on the 6-outlet distribution block, and up to 50 feet long on the 4-outlet main panel. The optional panel mount receptacle, model 30FR4X, intended for main power input, is the latest addition to the system and provides additional flexibility and convenience for the system end user.
• Both the CBI and JBB type commercial systems add the capability of using 72 inch thermostatically controlled heaters by incorporation a primary spider in place of the 3B20-6SR distribution block. Accordingly, the system may be configured using either the primary spider or the 6 outlet distribution block. The primary spider must be used if 72 inch heaters will be used in the system.
• Primary spiders (3 phase to single phase) must have 3 legs for phase balance. Secondary spiders (single phase) can have 2 or 3 legs. Length of cable can be up to 100 feet, per spider (overall length)