General - The Salem DC/SCR carriage drive is a complete system including a high performance direct current motor coupled to a gear reducer driving a cable drum, all mounted on a common steel base. The control system consists of a multi-processor controlled regenerative SCR drive working in conjunction with a Programmable Logic Controller (PLC) to provide maximum flexibility and performance. An operator control/status panel and heavy-duty control handle round out the package as truly being designed for use in a sawmill environment. The system is designed to provide high production, quick responsiveness, energy efficiency, and ease of maintenance.

Motor - Is a high performance direct current motor specifically designed for the continuous reversing parts of a log carriage. It is a drip proof, force ventilated motor with mounted blower and filter assembly, encoder, and internal thermostat. The motor armature is of a low inertia design resulting in a greater portion of the input power being used to drive the carriage. The motor commutator and armature construction allow for a peak overload capability of 200% of rated current to provide the high torque needed in a carriage application. Controller - Is an Allen-Bradley 1395 series four quadrant armature regenerative DC drive controller. The armature power assembly is a 12 SCR back-to back connected full wave converter. Control processors and regulator circuits are provided on four major circuit boards which are mounted in a layered card rack that swings out to allow for easy access. An Allen-Bradley SLC-500 PLC is incorporated into the drive system to provide additional program flexibility, analog control, and status annunciation to supplement the drives extensive built-in diagnostic capabilities.

Operator - Control is provided through two convenient control devices mounted in the saw cab. The first is a small NEMA 12 enclosure containing all necessary pushbuttons and status indicators for normal operation and trouble-shooting. Also included are ports which allow remote communications to the drive system so that tuning and extended diagnostics can be performed from the sawyer’s chair. The second device is a custom designed, heavy-duty speed control handle with a long life potentiometer and redundant safety switches for maximum protection. The handle is mounted on a rugged adjustable height pedestal and can be adapted to various types of sawyer’s handles.

Gearbox - Motor torque is transmitted to the cable drum through a standard parallel shaft double reduction gearbox sized conservatively to ensure a long trouble-free parts life. Exact ratios are determined for each application to optimize throughput and motor performance based on individual sawing requirements. Double engagement couplings are used on both the input and output shafts to minimize down time in the event parts is required.