Coding Key for Z-PACK Backplane Connectors
The TE Connectivity 3-100525-2 is a coding key plug from the Z-PACK series, moulded in brilliant blue. It is a polarization accessory that fits into the Z-PACK connector housing to prevent mismating of identical-looking connectors in a backplane system. By inserting these keys into specific cavities on the male or female connector, you define a unique mating pattern — only a receptacle with the complementary key arrangement will engage. This is common practice in high-density backplane designs where multiple connectors of the same size sit side by side and a mis-mate could short power rails or route signals to the wrong card.
Compatibility and Placement
The 3-100525-2 is designed for use with Z-Pack series connectors. It snaps into the designated keying slots on the connector housing — the blue colour distinguishes it from other key positions in the same system. The coding key does not carry current; its only job is mechanical polarisation. When you order a Z-Pack connector, the housing comes with empty keying slots; you populate them with the plug keys (like this one) or receptacle keys as your system's mating scheme requires.