Carrier 990-151-1A Head Pressure Motor Controller

Carrier Motormaster 32LT900-301 990-151-1A Head Pressure Motor Controller Assy is a solid-state head pressure controller assembly used within Carrier's Motormaster control platform to regulate compressor head pressure in compatible units. The module carries part numbers 32LT900-301 and 990-151-1A and is associated with the Motormaster I controller family (32LT900301), making it a direct replacement part for field service on Carrier commercial HVAC equipment. As a head pressure control device, it interfaces with the Motormaster control scheme to adjust motor drive signals to maintain target head pressure across changing operating conditions. Documented Carrier reference materials describe 32LT900301 as the motor controller component for Motormaster I configurations, and the assembly is sold as a replacement unit across retailer listings. The part is typically described in catalogs and installation guides as a solid-state controller, intended for integration in Carrier systems that use Motormaster head pressure control configurations, providing a compact, serviceable remedy within the control loop.