York 021-18660-000 Terminal Stud

021-18660-000 is the original factory terminal stud (Terminal Stud, also known as terminal bolt or compressor terminal) for the compressors of York (a brand under Johnson Controls) in the United States. It is mainly used in air-cooled piston-type units such as AWHC. The accessory information indicates that its reference numbers include 021-19104-000, TER-1160, TER-4902. The specifications are an outer diameter of 10.8 millimeters, a total length of 86.10 millimeters, and a single piece weighs approximately 0.08 kilograms. It is compatible with York J, K, L, M, and P series compressors (such as JG3/4, JK3/4, JL3/4, JM3/4, PA3/4, PB3/4, PC*3/4, etc.).
On fully enclosed or semi-enclosed compressors, the terminal stud is the only channel for the power supply to enter the machine: it passes through the compressor casing, is sealed with a glass or ceramic sintered insulator to the metal casing, one end is connected to the motor winding lead inside the machine, and the other end is connected to the wiring box outside the machine with the three-phase power supply. Therefore, this component must simultaneously meet three requirements - reliable conductivity, electrical insulation between the component and the casing, and maintaining airtightness in the refrigerant and refrigerating oil environment. Once the insulator cracks, the seal ages, or the terminal is burned out, there will be leakage, ground short circuit, refrigerant leakage, or overheating and melting of the terminal connection, which is one of the common causes of electrical faults in compressors.