Product Description:

The 40PA56-55-TEFC-G retrofit assembly is produced by Pacific Scientific for its Permanent Magnet DC Motors series. It is a field-installable conversion set that equips a standard 55-frame permanent-magnet DC motor for tachometer-based closed-loop service. When the kit is installed, it provides a protected motor enclosure and an external speed-feedback connection needed in conveyors, mixers, and tension-control lines where constant velocity must be maintained despite load changes and airborne contamination. This type of retrofit is useful when an existing DC motor must be upgraded for regulated speed control without replacing the entire drive package. By adding feedback capability to a conventional motor package, the assembly supports more stable speed correction during changing process loads.

Its mechanical interface follows the Adapter Size classification of Large, so the bracket fits the existing end bell without machining or shims. For electrical feedback, the housing includes a machined pilot that accepts a Baldor tachometer type BTG or a GE model 5PY, allowing either sensor style to be used. Environmental protection follows the TEFC standard, indicating a totally enclosed, fan-cooled motor body that helps keep the windings at a safe temperature while limiting dust and moisture entry. Because the conversion preserves the base motor mounting relationship, it can be added to established machine layouts without changing the drive-end structure. The enclosed cooling arrangement also supports use in areas where airborne debris would be undesirable around the motor internals.

The kit is supplied as parts and instructions, so installation requires only common shop tools. It is matched to the SRF55 motor designation, and the motor must carry the factory suffix -84 to confirm the correct shaft length and end-bell geometry. Because tachometer excitation is user supplied, the control panel must provide a fused low-voltage source that meets the electrical requirements of the selected sensor. This arrangement allows the chosen tachometer to be powered from the machine control system rather than from a built-in source inside the kit. The provided documentation supports correct assembly of the feedback hardware and proper alignment during installation.