October 20, 2009 — Weidmuller announces that their line of screw clamp terminals, the W-Series, have received an Underwriters Laboratory (UL) approval for the use of multiple wires per contact in a single terminal. The new approval, UL 1059, assures users that the approved terminals are acceptable for use in applications that may require more than one conductor per clamp.For end users that follow NFPA 79 industrial control panel wiring practices, terminal blocks can only accommodate one conductor under a clamping mechanism. However, for OEMs who follow NEC guidelines, more than one conductor per terminal point may be used. The OEM must calculate and determine the correct combination of multiple wire sizes to be clamped.
An error in calculation could potentially lead to future failures if the wrong combination is used in the terminal clamp.This new rating provides OEM users of Weidmuller’s W-Series terminals a savings in both time and materials. It reduces the number of terminals required for applications that would normally require one terminal for each conductor. In addition, for users that follow the NEC guidelines, Weidmuller provides a definitive guide that details the approved number of wires, per wire size, for each terminal block. The UL 1059 approved W-Series terminals include TS-35 DIN-rail mounted feed-through, ground, fuse, disconnect, branch and dual lever configuration types with electrical ratings of 300-600V, 10 – 175A and 22 – 2/0 AWG.
Weidmuller is the leading provider of solutions for the transmission of power, data and control signals in industrial environments. The company develops, produces and sells industrial electronics, network infrastructure components and connectivity solutions such as Wireless Solutions, Industrial Ethernet, Relays, Power Supplies, I/O modules, printed circuit board connectors, terminal blocks and complete DIN Rail assemblies. The Weidmuller group has a strong international focus with manufacturing and sales locations in over 70 countries.