Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 39 - SAFETY STANDARDS-GENERAL › Subchapter B - ELECTRIC SAFETY › METHODS OF PROTECTIVE GROUNDING › Section 39.65 - Ground conductor

Current through Register Vol. 54, No. 28, July 13, 2024
(a)
Material and continuity.
The ground conductor shall be of
					 copper or of other metal which will not corrode excessively under the existing
					 conditions and, if practicable, shall be continuous. Joints shall be made and
					 maintained so as to conform to the resistance and current-carrying capacity
					 requirements of §
											39.69 (relating to ground
					 resistance). Ground connections from circuits should not be made to jointed
					 piping within buildings, except that water piping outside of meters and beyond
					 any point which is liable to disconnection, may be used. Reference should also
					 be made to §
											39.68 (relating to methods of
					 ground connection). No automatic cutout shall be inserted in the ground
					 conductor or connection except in a ground connection from equipment where its
					 operation will immediately result in the automatic disconnection from all
					 sources or energy of the equipment so grounded; no switch shall be so inserted
					 except in plain sight, provided with distinctive marking and effectively
					 isolated from unqualified persons. Reference should also be made to §
											39.67 (relating to attachment of
					 ground conductor).
(b)
Size
					 and number.
The size and number of ground conductors shall be as
					 follows:
(1) For grounding circuits the
					 ground conductors shall have a combined cross section and current capacity
					 sufficient to insure the continuity of the ground connection and its continued
					 compliance with §
												39.69, under conditions of excess
					 current caused by accidental grounding of any normally ungrounded conductor of
					 the circuit. No individual ground conductor for electrical circuits shall have
					 less current capacity than that of a No. 6 copper wire, except that for
					 additional grounds after the first on any circuit, smaller ground wires may be
					 used, provided that they are in no case smaller than the conductor to which
					 they are attached nor smaller than No. 10 copper.
(2) For lightning arrester ground connections
					 the ground conductor or conductors shall have a current carrying capacity
					 sufficient to insure continuity of the ground connection under conditions of
					 excess current caused by or following discharge of the arrester. No individual
					 ground conductor shall be smaller than a No. 6 wire.
(3) Electrical equipment shall conform to the
					 following:
(i) For electrical equipment the
					 current-carrying capacity of a ground conductor shall be not less than that
					 provided by a copper wire of the size indicated in the following table:
Capacity of Nearest Automatic Cutouts (in
								  amperes)
Required Size of Ground Conductor
								  A.W.G.
200-500
4
100-200
6
30-100
10
10-30
14
(ii) If there is no cutout protecting the
					 equipment, the size of ground conductor shall be determined by the design and
					 operating conditions of the circuit.
(iii) In the portable cord to portable
					 equipment protected by fuses not greater than 10-ampere capacity, a No. 18
					 ground wire may be used.