Weidmuller gets UL approval for multiple wire termination, contact for screw clamp terminals

The Weidmuller line of screw clamp terminals, the W-Series, received an Underwriters Laboratory (UL) approval for the use of multiple wires per contact in one terminal.
October 22, 2009

The Weidmuller line of screw clamp terminals, the W-Series, received an Underwriters Laboratory (UL) approval for the use of multiple wires per contact in one 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, Weidmuller says.

Weidmuller W-Series clamping yoke screw connection terminal blocks

Weidmuller W-Series clamping yoke screw connection terminal blocks

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, Weidmuller says. 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 time and materials, the company says. 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 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.

Learn from from Weidmuller about the UL 1059 approved Weidmuller W-Series screw clamp terminal blocks .

To see the certification, at Underwriters Laboratory site search the Online Certifications Directory for Weidmuller file number E60693.

Learn more from Control Engineering about fast, flexible terminal blocks .

– Edited by Mark T. Hoske, editor in chief, Control Engineering , www.controleng.com