The Allen-Bradley 100-D420-VTTB device kit is a connecting component kit for MCS D contactors that have been developed by Allen-Bradley/Rockwell Automation. It is an output connection kit intended for use with the Allen-Bradley Bulletin 100-D non-reversing types of contactors. It is, more specifically, an output connection component kit that is designed for the Bulletin 100-D series frame terminal blocks and that can be used with the Bulletin 100-D series contactors. When a frame terminal block is installed on a contactor, the enclosure protection rating of the contactor is increased to IP 20 in accordance with the IP 20 IEC 60529 and DIN 40 050 standards. The 100-D420-VTTB output connector kit can also be used with Bulletin 100-D series terminal lugs with the catalog number 100-DTB. The lugs come with IP2X-rated enclosures for protection per the IEC 60529 and DIN 40 050 standards.

The Allen-Bradley 100-D420-VTTB kit must be ordered separately from the main contactor. The 100-D420-VTTB kit is intended for use with Allen-Bradley Bulletin 100-D contactors with catalog numbers ranging from 100-D210 to 100-D420. For other contactors, different connecting components have to be utilized instead. It is compatible with non-reversing IEC contactors with a maximum operating current ranging from 210 Amps to 420 Amps for AC-3 utilization category applications. The 100-D420-VTTB output connection kit accepts a conductor with a cross-section of up to 120 square millimeters for the output connection. Users can build an application-specific system by using the Bulletin 100-D series' extensive range of accessories and replacement parts, such as the 100-D420-VTTB output connection kit. It supports output power ratings of up to 650 Horsepower at 575 Volts when it is used to assemble a Wye-Delta starter at 60 Hertz with a Bulletin 100-D contactor. When assembling a Wye-Delta starter, it can be combined with other Allen-Bradley accessories such as terminal shields, terminal covers, and mounting plates.