The 100-D180-VTTB connector is a Delta-Wye connector that is available in the connecting components accessories catalog of the IEC 100 Contactors and Bulletin 100-D contactors series that are manufactured by Allen-Bradley. The Delta-Wye connection is a type of 3-phase electric power transformer connection. This connection uses Delta-connected windings on its primary and secondary Wye stars. The Allen-Bradley 100-D180-VTTB Delta-Wye connector operates with output values only and it has been designed to operate with the Allen-Bradley 100-D115 to 100-D180 series contactors only. It has a cross-section that is 50 millimeters square and it operates as a reversing device. The Allen-Bradley 100-D180-VTTB Delta-Wye connector is connected to other devices through the terminal blocks that are also connected to the contactor that it works with.

The Allen-Bradley 100-D180-VTTB Bulletin 100-D Delta-Wye connector operates with contactors with voltage ratings of 24 to 250 Volts DC. The main purpose of using this connector is to affect the voltage that is applied to the windings. This connector is one of the available electromechanical methods for reducing the voltage applied to the system motor in the starting phase. The Allen-Bradley 100-D180-VTTB Delta-Wye connector comes in a package of one connector and more connectors can be ordered from the same Bulletin 100-D accessories catalog. It is meant to be used with contactors that operate as industrial control equipment alongside motors. This connector can be used with single-phase or 3-phase transformers, and this means that it is compatible with multiple applications that require voltage control. Like any type of connector, this connector should be installed by a technician since improper wiring could affect the whole system negatively.