A3 series for Tachometers and Encoders

The patented SGS^TM A3 series shaft grounding systems are designed to control damage caused by shaft-to-frame capacitive discharge through bearings in motors, gears, shafts, couplings, and rolls by providing a single low impedance pathway from the shaft to the frame of hard coupled equipment.

The SGS^TM A3 series kits are designed to mount on the outboard end of common pancake style industrial tachometers or motor accessory brackets with the 8.5 inch mounting register. The unit normally requires approximately 6 inches of axial clearance for installation and infrequent maintenance. However, closer clearances may be acceptable. Installation requires removing the outboard cover of the tachometer to mount the SGS^TM rotor onto the tachometer rotor then replacing the outboard tachometer cover with the A3 body assembly.

This shaft grounding system is not rated explosion proof. If eddy currents are present, and no motor bearing is insulated, two shaft grounding systems should be installed to pass the eddy current around both motor bearings while also controlling the capacitive discharge. In our experience, eddy currents are not normally a problem except on larger AC motors (200hp or larger) or in low RPM scenarios (1200rpm or less). If one motor bearing is insulated to control eddy current, one shaft grounding system should be used at the non-insulated bearing to control the shaft-to-frame capacitive discharge. A single insulated bearing will not control capacitive discharge through the non-insulated bearings. Call to discuss situations where multiple sources of shaft-to-frame potential exist.