Specifications

PIP ELCGL01
Electrical Design Criteria November 2002
Page 6 of 20 Process Industry Practices
• National Electrical Manufacturers Association (NEMA)
–NEMA VE1 - Cable Tray Systems
• National Fire Prevention Association (NFPA)
– NFPA 70 - National Electrical Code (NEC)
– NFPA 70E - Standard for Electrical Safety Requirements for Employee
Workplaces
– NFPA 77 - Recommended Practice on Static Electricity
– NFPA 496 - Purged and Pressurized Enclosures for Electrical Equipment in
Hazardous (Classified) Locations for Electrical Installations
– NFPA 497 - Classification of Flammable Liquids, Gases, or Vapors and of
Hazardous (Classified) Locations for Electrical Installation in Chemical
Process Areas
- NFPA 499 - Classification of Combustible Dust and of Hazardous (Classified)
Locations for Electrical Installation in Chemical Process Areas
– NFPA 780 - Standard for the Installation of Lightning Protection Systems
3. System Design Criteria
3.1 General
The complete electrical system shall be designed to enhance personnel safety and to
minimize environmental exposure of the electrical equipment. In addition, the
electrical systems shall be designed for lowest life cycle cost, continuous and reliable
service, equipment protection, ease of maintenance and operation, mechanical
protection of equipment, interchangeability of equipment, and the addition of future
loads. Equipment listed or labeled by a nationally recognized testing laboratory
(NRTL) shall be used when available.
3.2 Electrical Code Compliance
All electrical systems and installations shall conform to the NFPA 70 (NEC),
NFPA 70E, and NESC as applicable and to any other applicable codes that are listed
on the Data Sheet.
3.3 System Protection and Coordination
3.3.1 Incident energy for three-phase arcing faults shall be calculated for all new
electrical facilities per NFPA 70E. Other electrical system studies shall be
provided when required on the Data Sheet. Software program(s) as specified
on the Data Sheet shall be used for any required studies. Any files and
libraries created in such studies shall be provided to the owner. Such files
include paper files, electronic files, and native files required to run system
studies.
3.3.2 System protective devices (relays, fuses, etc.) shall be selected and
coordinated to ensure that the upstream-interrupting device nearest the point
of fault (or overload) will open first and minimize system disturbance.