Specifications

PIP ELCGL01
Electrical Design Criteria November 2002
Page 14 of 20 Process Industry Practices
a. adjacent building or structure steel
b. reinforcing mesh or bars in the concrete foundation
c. adequately sized bare, tin-coated or green-colored, covered copper
conductor around the equipment foundation and connected to at least
two ground rods or the ground grid
8.3.3 If specified on the Data Sheet all 460-volt motors shall also be bonded by
one of the methods mentioned in the section above.
8.3.4 When conditions require the use of cathodic protection, grounding systems
may require different designs.
8.4 Plant Grounding System
8.4.1 The grounding system shall be as specified on the Data Sheet.
8.4.2 Where a ground loop system is specified on the Data Sheet, taps from the
ground loop to all major equipment and structural steel shall be provided.
8.4.3 For facilities outside of plant ground grid, a grounding system shall be
provided. Connection of the remote grounding system to the plant grounding
system is recommended.
8.4.4 The plant grounding system impedance to earth shall not exceed 5 ohms.
Results shall be obtained by methods identified in PIP ELTFT01.
8.4.5 Connections to the grounding system and the minimum depth of the buried
grounding system shall be as shown on the Data Sheet or as detailed in
PIP ELIGD000.
8.4.6 Instrument grounding shall be installed according to PIP PCCEL001.
8.4.7 Where bare underground cables are connected to cathodically protected
systems, the cathodic protection current flow to the cable can be
significantly reduced by use of tin-coated copper cable. If specified on the
Data Sheet, tinned copper cable shall be installed.
8.5 Static Electricity Grounding
8.5.1 Static grounding is not required if the impedance between units of equipment
is less than 1.0 megohm.
8.5.2 Tank trucks, tank cars, portable drums, marine craft, storage tanks, vessels,
agitators, etc., shall be protected against static electricity, lightning, and stray
currents. Refer to API RP2003, NFPA 77, and NFPA 780 for details.
9. Lighting
9.1 Illumination Levels
Illumination levels shall be in accordance with Table 3 of API RP540 unless
specified otherwise on the Data Sheet.