Exposed noncurrent-carrying metal parts of all trailers and other equipment shall be grounded in one of the following ways:
A. By means of a grounding conductor run with the circuit conductors in cable assemblies of the approved outdoor type or flexible cords type S or equal, provided an approved multiprong plug or equivalent is used, one prong for the purpose of connecting such grounding conductor to the grounded metal raceway or cable armor. This conductor may be uninsulated but if an individual covering is provided for this conductor it shall be finished to show a green color. An additional contact shall be provided in the receptacle for grounding purposes.
B. Any equipment directly connected to a grounded metallic wiring system is acceptable in lieu of the requirements of subsection A of this section. Exposed noncurrent-carrying metal parts of motors, generators, and control equipment such as frames of motors and control panels, operating levers, and casings of controllers, switches, etc. shall be effectively grounded under the following conditions:
1. All motors, whether fixed or portable, regardless of voltage in all locations where exposed grounded surfaces such as metal frames, conducting floors or walls exist within the reach of persons when touching the metal parts under consideration; grounded surfaces within five feet horizontally of the parts considered and within eight feet vertically of the floor or working platform are considered as being within reach;
2. All portable electric tools which are held in the hand while being operated, regardless of voltage;
3. When the motor is not otherwise effectively grounded and when the voltage exceeds one hundred fifty volts to ground, a bond will be required between the motor frame and the rigid conduit or electrical metallic tubing in cases where the rigid conduit or electrical metallic tubing does not terminate in a junction box which is grounded to the motor frame. When the voltage does not exceed one hundred fifty volts to ground, the motor frame may be grounded through flexible metal conduit which is properly connected to the motor and to the rigid metal conduit.
(Prior code § 17.16.240(V) (Ord. 503 § 15.5 (v), 1961))