Grounding and Bonding Permitted Methods

Grounding is one of the most taken for granted provision of the Philippine Electrical Code. The incompetence of Electrical Inspectors make this practice worst.

I inspected the grounding system of a 13.8kV Ring Main Unit (RMU) installed in our plant only to find out that grounding conductors were not terminated nor connected to any grounding equipment. This practice makes the installation dangerous particularly in the event of a ground fault.

The Philippine Electrical Code 2008 and the National Electrical Code (NFPA 70) provides permitted methods of grounding and bonding electrical equipment.

PEC 2008 Edition
2.50.1.8 Connection of Grounding and Bonding Equipment. Grounding conductors and bonding jumpers shall be connected by exothermic welding, listed pressure connectors, listed clamps, or other listed means. Connection devices or fittings that depend solely on solder shall not be used. Sheet metal screws shall not be used to connect grounding conductors or connection devices to enclosures.

NFPA 70 - 2011 Edition
250.8 Connection of Grounding and Bonding Equipment.
(A) Permitted Methods. Equipment grounding conductors, grounding electrode conductors, and bonding jumpers shall be connected by one of the following means:
(1) Listed pressure connectors

(2) Terminal bars

(3) Pressure connectors listed as grounding and bonding equipment
(4) Exothermic welding process

Exothermic Thermite Product


(5) Machine screw-type fasteners that engage not less than two threads or are secured with a nut
(6) Thread-forming machine screws that engage not less than two threads in the enclosure
(7) Connections that are part of a listed assembly
(8) Other listed means
(B) Methods Not Permitted. Connection devices or fittings that depend solely on solder shall not be used.

About the Author

Ver Pangonilo
A Filipino Engineer, Registered Professional Engineer of Queensland (RPEQ) - Australia and Professional Electrical Engineer (PEE) - Philippines with extensive experience in concept select, front-end engineering, HV & LV detail design, construction and commissioning of Hazardous and Non-Hazardous Area electrical installations in water and waste water pipeline and pumping facilities, offshore platforms, hydrocarbon process plants and pipelines including related facilities. Hazardous area classification and design certification (UEENEEM015B, UEENEEM016B, UEENEEM017B).
WP Facebook Auto Publish Powered By : XYZScripts.com