Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum

Facilities for Unclassified and Class I, Division 1, and Division 2 Locations

API RECOMMENDED PRACTICE 14F SIXTH EDITION, OCTOBER 2018

Special Notes

API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.

Neither API nor any of API’s employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of API’s employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.

API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to ensure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.

API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.

Users of this recommended practice should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.

API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations to comply with authorities having jurisdiction.

Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.

All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, NW, Washington, DC 20005.

Copyright © 2018 American Petroleum Institute

Foreword

This recommended practice (RP) contains information for use primarily by engineers with a working knowledge of electrical systems and production operations. Some of the information can be useful to experienced electrical maintenance and operating personnel. The intent of the document is to identify important features of offshore electrical systems and to present generally accepted practices for electrical design and installation that experience in the offshore petroleum industry has shown results in safe, reliable, efficient, and maintainable operations. Nothing in this RP is to be construed as a fixed rule without regard to sound engineering judgment, nor is it intended to supersede or override any federal, state, or local regulation where applicable.

The First Edition of API 14F was published in July 1978 as API 14F, Design and Installation of Electrical Systems for Offshore Production Platforms, under the jurisdiction of the API Production Department. The Second Edition was published on July 1, 1985. The Third Edition was published September 1, 1991. The Fourth Edition was published June 1999, with a new title, Recommended Practice for Design and Installation of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Division 1 and Division 2 Locations. The Fifth Edition was published in July 2008. A related document, API 14FZ, Recommended Practice for Design and Installation of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Zone 0, Zone 1 and Zone 2 Locations, First Edition, was published in September 2001 to address zone classifications and wiring methods introduced initially in Article 505 of the 1996 National Electrical Code (NEC) and referenced the 1999 NEC. API RP 14FZ Second Edition was published in May 2013 to address zone classifications and wiring methods in Article 505 in the 2011 NEC.

This document includes usage of the verbs shall and should—whichever is the more applicable to the function. For the purpose of this document:

Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.

Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.

May: As used in a standard, “may” denotes a course of action permissible within the limits of a specification. Can: As used in a standard, “can” denotes a statement of possibility or capability.

This RP shall become effective on the date printed on the cover but may be used voluntarily from the date of distribution.

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.

This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.

Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standards@api.org.

Contents

Page

1. Scope 1

   1. General 1

   2. Applicability of the National Electrical Code 1

2. Normative References 1

   1. Industry Codes, Guides, and Standards 1

   2. Government Codes, Rules, and Regulations 5

   3. Classification Society Rules and Regulations 6

3. Acronyms, Abbreviations, and Definitions 6

   1. Acronyms and Abbreviations 6

   2. Definitions 8

   3. Definitions Specific to Floating Facilities 22

4. Electrical Equipment for Hazardous (Classified) Locations 23

   1. General 23

   2. High-temperature Devices 24

   3. Protection Techniques Related to Equipment Installed in Locations Classified

      as Division 1 or Division 2 24

   4. Protection Techniques Related to Equipment Approved for Zones Used in Division Locations 26

   5. General Purpose Equipment 29

   6. Listing, Marking, and Documentation 29

5. Electric Power Generating Stations 30

   1. General 30

   2. Prime Movers 31

   3. Generators 34

   4. Generator Packaging Considerations 40

   5. Switchboards and Switchgear 41

   6. Special Requirements for Floating Facilities 43

6. Electrical Distribution Systems 46

   1. Scope 46

   2. Voltage Level Selection 46

   3. Conductor Selection 47

   4. Wiring Methods for Hazardous (Classified) Locations 57

   5. Wiring Methods for Unclassified Locations 62

   6. Wiring Methods for Drilling and Workover Rigs 62

   7. General Wiring Considerations 63

   8. Conduit and Cable Seals and Sealing Methods 68

   9. Circuit Protection 79

   10. Grounding 80

   11. Electrical Enclosures 83

   12. Working Space About Electrical Equipment and Means of Access 89

   13. Additional Requirements for Floating Facilities 91

7. Electric Motors 91

   1. General 91

   2. Selection 91

   3. Motor Space Heaters 93

   4. Motor Control 94

      Contents

      Page

8. Transformers 96

   1. General 96

   2. Selection 96

   3. Installation 97

   4. Connections 98

   5. Protection 99

9. Lighting 99

   1. General 99

   2. Lighting Levels 100

   3. Fixture Selection and Installation 102

   4. Emergency Lighting 104

   5. Lighting for Helicopter Operations 105

10. Battery Backup Powered Supply Systems (DC Charger/Uninterruptible Power Supplies) 107

    1. General 107

    2. Specific Applications 107

    3. Stationary Batteries 108

    4. Battery Chargers 112

    5. Uninterruptible Power Supply Systems 114

11. Special Systems 116

    1. Safety Control Systems 116

    2. Gas Detection Systems 118

    3. Fire Detection Systems 120

    4. Aids-to-Navigation Equipment 121

    5. Communications Equipment 122

    6. Heat Trace Systems 123

    7. Fire Pumps 123

    8. Adjustable Speed Drives (Variable Frequency Drives) 123

    9. Submarine Cables 130

    10. Electric Oil-immersion Heaters 130

    11. Electric Power-operated Boat Winches for Survival Craft 131

    12. Electric Power-operated Watertight Doors 131

    13. Hull Mechanical System Controls 131

    14. Cargo Tanks on Floating Facilities 132

    15. Cargo Handling Rooms on Floating Facilities 132

    16. General Alarm System 132

    17. Cathodic Protection 135

    18. Subsea Electrical Systems 137

    19. Integrated Marine Monitoring System and Tendon Tension Monitoring System 138

12. Special Considerations 139

    1. Construction Practices 139

    2. Electronic Instrumentation 141

    3. Electrical Tools and Cord Connected Devices 141

    4. Electrical Appliances 142

    5. Extension Cords 142

    6. Electrical Equipment Buildings 142

    7. Laboratory Buildings 142

    8. Signs 142

       Contents

       Page

    9. Lockout and Tagout Procedures 142

    10. Portable Electronic Devices (Products) 143

    11. Abandoned Raceways and Conductors 143

13. System Checkout 143

    1. General 143

    2. Generators and Motors 143

    3. Instrumentation and Control Circuits 143

14. Maintenance 144

15. Safety 144

Annex A (informative) Inspection Intervals 145

Annex B (informative) ABS Rules for Building and Classing Steel Vessels—2015, PART 4 147

Annex C (normative) USCG Requirements, 46 CFR, Subchapter J, 111.95 155

Annex D (normative) USCG Requirements, 46 CFR, Subchapter J, 111.97 156

Annex E (informative) USCG Requirements, 46 CFR, Subchapter J, 111.105 157

Annex F (informative) Electrical Inspection Checklist 163

Annex G (informative) Example AC Top Drive Power Service Loop Ampacity Calculations 166

Bibliography 173

Figures

1. Typical Class I, Division 1 Electrical Installation Conduit System 69

2. Typical Class I, Division 1 Electrical Installation Cable System 70

3. Typical Class I, Division 2 Electrical Installation Conduit or Cable System 71

4. Typical Class I, Division 2 Electrical Conduit or Cable Installation Utilizing Class I,

   Zone 0, 1, or 2 Equipment and Division 2 Wiring Methods 72

5. Typical Class I, Division 1, or Division 2 Electrical Installation Conduit and Cable

   Connections to Process-connected Nonarcing Devices with Single-seal Diaphragm or Tube 73

6. Typical Class I, Division 1, or Division 2 Electrical Installation Conduit and Cable

   Connections to Process-connected Nonarcing Devices with Multiple-seal Diaphragms or Tubes 74

7. Typical Class I, Division 1, or Division 2 Electrical Installation Conduit or Cable Connections to Flammable Fluid Process-connected Nonarcing Devices with

   Multiple-seal Diaphragms or Tubes 75

8. Typical Class I, Division 1, or Division 2 Electrical Installation Placement of Drain Seals 76

9. Typical Speed Torque Curve for Variable Torque Load 126

10. Typical Speed Torque Curve for Constant Torque Load 126

11. Typical Speed Torque Curve for Constant Horsepower Load 127

12. Typical Speed Torque Characteristics for Impact-type Loads 128

1. Top Drive Installed in Derrick with Power Service Loop Potted Entire Length 166

2. Top Drive Installed in Derrick with Power Service Loops Potted Entire Length 168

3. Top Drive Installed in Derrick with Power Service Loop Potted at Each End Only 170

4. Top Drive Installed in Derrick Drill Motor Power Cables Routed Through Drag-Chain 171

Tables

1. Types of Protection Designation for Zone Equipment Used in Divisions 27

   Contents

   Page

2. Ampacities for Marine Shipboard Distribution, Control, and Signal Cables,

   2000 V or Less, AC or DC, Copper Conductors, Single-banked (Single-layered),

   Maximum Current-carrying Capacity Based on 45 ºC (113 ºF) Ambient 48

3. Allowable Ampacities of Insulated Nickel-coated Copper Conductors (27 % Nickel)

   Rated 0 Through 2000 V, 75 °C, Not More Than Three Current-carrying Conductors

   in Raceway, Cable Maximum Current-carrying Capacity Based on 45 °C (113 °F) Ambient 49

4. Ampacities for Marine Shipboard Single-conductor Distribution Cables,

   2000 V or Less, DC Only, Copper Conductors, Single-banked (Single-layered), Maximum Current-carrying Capacity Based on 45 °C (113 °F) Ambient 49

5. Ampacity Adjustment Factors for More Than Three Conductors for Tables 2, 3, and 4 50

6. Ampacities for Three-conductor Medium-voltage Power Cable, 2001 V to 35 kV,

   Copper Conductor Single-banked (Single-layered), Maximum Current-carrying Capacity

   Based on 45 °C (113 °F) Ambient 51

7. Ampacities for Medium-voltage Power Cable, 2001 V to 35 kV, Copper Conductor Single-conductor in Triplexed or Triangular Configuration, Maximum Current Carrying

   Capacity Based on 45 °C (113 °F) Ambient 52

8. Ampacities for Single-conductor Medium-voltage Power Cable, 2001 V to 35 kV,

   Copper Conductor Single-banked (Single-layered), Maximum Current-carrying Capacity

   Based on 45 °C (113 °F) Ambient, Shields Grounded on One End (Open-circuited Shields) 53

9. Medium-voltage Power Cable, 2001 V to 35 kV Adjustments for Tables 6, 7, and 8 54

10. Wiring Methods for Hazardous (Classified) Locations 58

11. Commonly Available Power and Control Cables Sizes and Configurations 67

12. Commonly Available Instrumentation Cable Sizes and Configurations 68

13. Circuit Protection Devices—Advantages and Disadvantages 79

14. NEMA Enclosures 84

15. Degree of Protection of Enclosures in Accordance with IEC 60529 87

16. Selection of IEC 60529 IP Rated Enclosures to Meet NEMA Requirements 88

17. Selection of NEMA Enclosures to Meet IP Designations 89

18. Working Clearances 90

19. NEMA Motor Starter Sizing 94

20. Minimum Maintained Levels of Illumination for Efficient Visual Tasks 101

21. Minimum Maintained Levels of Illumination for Safety 102

22. Comparison of Batteries by Cell Type 109

23. Alarm Tones for Fixed Facilities 133

24. Alarm Tones for Floating Facilities 135

A.1 Recommended Inspection Intervals 145

Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Division 1 and Division 2 Locations

1. Scope

   
   

   1. General

      
      

      1. This document recommends minimum requirements and guidelines for the design, installation, and maintenance of electrical systems on fixed and floating petroleum facilities located offshore. For facilities classified as Zone 0, Zone 1, or Zone 2, reference API RP 14FZ, Recommended Practice for Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class I, Zone 0, Zone 1, and Zone 2 Locations. These facilities include drilling, producing, and pipeline transportation facilities associated with oil and gas exploration and production. This recommended practice is not applicable to mobile offshore drilling units (MODUs) without production facilities. This document is intended to bring together in one place a brief description of basic desirable electrical practices for offshore electrical systems. The recommended practices contained herein recognize that special electrical considerations exist for offshore petroleum facilities. These include the following:

         
         

         1. the inherent electrical shock possibility presented by the marine environment and steel decks;

            
            

         2. space limitations that require that equipment be installed in or near hazardous (classified) locations;

            
            

         3. the corrosive marine environment;

            
            

         4. motion and buoyancy concerns associated with floating facilities.

         
         

      2. This recommended practice applies to both permanent and temporary electrical installations. The guidelines presented herein should provide a high level of electrical safety when used in conjunction with well- defined area classifications. This recommended practice emphasizes safe practices for hazardous (classified) locations on offshore petroleum facilities but does not include guidelines for classification of areas; for guidance on the classification of areas refer to API RP 500.

         
         

         1.2 Applicability of the National Electrical Code

         
         

         Electrical systems for offshore petroleum facilities shall be designed and installed in accordance with the National Electrical Code (NEC), 2017 edition, except where specific departures are noted.

         
         

2. Normative References

   
   

   1. Industry Codes, Guides, and Standards

Various organizations have developed numerous codes, guides, and standards that have substantial acceptance by industry and governmental bodies. Codes, guides, and standards useful in the design and installation of electrical systems are listed below as references only. These are not considered to be a part of this recommended practice except for those specific sections of documents referenced elsewhere in this recommended practice.

API RP 2L, Recommended Practice for Planning, Designing, and Constructing Heliports for Fixed Offshore Platforms

API RP 14C, Recommended Practice for Analysis, Design, Installation, and Testing of Basic Surface Safety Systems on Offshore Production Platforms