Replacement HK 02UB 042 Pressure Switch

HK02UB042 Pressure Switch is a replacement component used in Carrier/UTC HVAC systems to monitor operating pressure and activate control circuits when a set pressure is reached. The device senses pressure changes in the system in the 30 to 55 psi range, causing its internal contacts to switch state to indicate high or low pressure. It is rated for standard line voltages of 120, 240, or 277 VAC, allowing direct integration with common control boards and relays in air handlers, condensers, and related equipment. The part is cataloged under NSN 5930-00-103-9313 as a general pressure switch, and Carrier/UTC references identify it as HK02UB042. In some distributor catalogs, HK02UB042 is listed as obsolete, with notes that replacement options may be available through authorized Carrier distributors. This designation is used across multiple listings as a pressure control component associated with Carrier units, making it a frequent choice for replacement when the original HK02UB042 is specified in service manuals or equipment records. When selecting a replacement or performing replacement, ensure the new switch matches the same pressure setpoints (30/55 psi) and voltage ratings (120/240/277 VAC) and that the mounting and electrical connection scheme correspond to the original installation in your HVAC equipment.