Electrical hazards, lockout-tagout, personal protective equipment and insulated tools

Functions of VFD

Motion control/motor speed, air flow/liquid flow/pressure control, eliminating the need for variable transmission or sheave, variable vanes or dampers on fans, variable valves on pumps

Benefits of using a VFD

Energy savings, easier maintenance, enhanced system monitoring

Load types

Constant torque–conveyors, positive displacement pumps, superchargers, variable torque– centrifugal fans or pumps, saws, routers, planers

VFD options   

Bypass—two or three contactor style, disconnect switch style, soft starter, fusing VFD or bypass protection, motor overload device, transient protection, auxiliary relays, powerline phase reversal detection

Installation of a VFD

Environmental concerns, clearances, conduit entry

Customer connections

Safety circuit, start/stop, jog, status indication, fault indication, remote speed reference, monitoring of motor parameters)

Wiring and grounding VFDs

Induced signals, inductive, capacitive, incoming powerline wiring, motor (load) wiring, control wiring, proper grounding methods

Controlling a VFD

Keypad controls, terminal strip control (automatic and manual),bus communication control, open loop control, manual operation, automatic operation, sensor-less flux vector, closed loop control, Pi loop configuration, sensor or transducer feedback, motor shaft encoder feedback

VFD setup, programming and troubleshooting

            The importance of monitoring the VFD, maintenance, considerations for a VFD, identifying and isolating a VFD problem from a motor problem, troubleshooting the most common VFD problems.