A motor drive system comprises a motor driven by a variable frequency power supply and a machine driven by the motor, which are mechanically connected by the drive shaft of the motor and the shaft of the machine via bearings. A stationary portion of the motor and the frame of the machine are electrically connected by a low-impedance conductor, so that a current can be caused to flow at least partially between the stationary portion of the motor and the frame of the machine.

An electrically-conductive terminal adapted for use in an electrical connector includes a horizontal upper surface containing a downwardly extending first bore in which is mounted a U-shaped protective spring. The spring has a bulging generally circular bridging portion adjacent the bottom of the first bore, and a pair of upwardly extending leg portions. One of the leg portions is adapted to be displaced by a clamping screw mounted in a threaded horizontal second bore toward clamping engagement with a bare conductor that is inserted downwardly into the first bore. The bulging bridging portion of the spring extends into diametrically opposed recesses contained in the wall of the first bore and defined by a horizontal third bore, thereby to retain the protective spring in the first bore.

A bonding lug apparatus for devices such as electric motors installed within a distance of a fluid-holding apparatus such as pools, hot tubs, spas, and the like, is provided that includes a fastener having a head and a bonding lug having an aperture that receives the fastener such that a bonding conductor of a bonding grid of the fluid-holding apparatus area is captured between the head of the fastener and the bonding lug. The bonding lug apparatus bonds the electric motor to the bonding grid of the fluid-holding apparatus area when the bonding lug apparatus is electrically coupled to the electric motor and the bonding conductor.

An improved electrical plug-and-socket connectors with screw-type clamping connections has a step-shaped screw brake for protecting against loss of the clamping screw of connecting stranded conductors of electrical components having as the clamping mode a screw-type clamping connection. The screw brake has one, two or more strips. The plug-and-socket connector has a screw-type connection, having an insulating part, arranged to accommodate at least one contact insert. The contact insert has a substantially cylindrical shape and comprises a contact portion for electrical/mechanical connection to an oppositely shaped contact piece of a matched plug-and-socket connector at a first end of the contact insert. It further comprises an insertion opening for at least one connecting stranded conductor at a second end of the contact insert, there opening in the insertion opening a screw hole which is oriented substantially transversely relative to the central longitudinal axis thereof and comprises an internal thread. The insulating part has a screw channel which is substantially in alignment with the screw hole when a contact insert is accommodated in the insulating part. The screw channel has at least one step. The inside width of the screw channel reduces from a first, greater dimension towards a second, lesser dimension in the direction towards the screw hole of the insertion opening. The screw channel has one or more strips which are oriented substantially coaxially relative to its central longitudinal axis of the and which are so dimensioned that a clamping screw to be inserted in the screw channel fastening the connecting stranded conductor in the insertion opening of the contact insert is subjected to a first, lesser resistance at the strip/strips of the first inside width, and is subjected to a second, greater resistance at the strip/strips of the second inside width.

An electric motor having an integrally formed bonding apparatus that allows an installer to quickly and efficiently bond the electric motor to a bonding grid of a bonding area. A fastener having a head is inserted into an aperture of the housing of the electric motor such that a bonding conductor is captured between the housing and the head. The bonding conductor is electrically coupled to the housing via direct contact between the bonding conductor and the housing and/or via indirect contact through the fastener. An integrally formed surface of the housing prevents the bonding conductor from moving out from under the head.