IEEE DRAFT 628 : R2 2001

1 Overview
1.1 Scope
1.2 Purpose
2 References
3 Definitions
4 Design
4.1 General
4.2 Separation criteria
4.2.1 Design requirements
4.2.2 Raceways
4.3 Grounding
4.4 Raceway identification
4.5 Raceway system protection
4.6 Environmental considerations
4.7 Materials
4.7.1 General
4.7.2 Metallic conduit
4.7.2.1 Rigid steel conduit (RSC)
4.7.2.2 Rigin aluminium conduit (RAC)
4.7.2.3 Intermediate metal conduit (IMC)
4.7.2.4 Electrical metallic tubing (EMT)
4.7.2.5 Flexible metal conduit
4.7.2.6 Fittings and accessories
4.7.3 Nonmetallic conduit
4.7.3.1 Polyvinyl chloride (PVC) conduit
4.7.3.2 Polyethylene (PE) conduit
4.7.3.3 Acroylonitrile-butadiene-strene (ABS) conduit
4.7.3.4 PVC fittings
4.7.3.5 ABS fittings
4.7.4 Cable trays, accessories, and fittings
4.8 Metallic raceway system finishes
4.8.1 General
4.8.2 Manufacture-applied finishes
4.8.2.1 Galvanizing
4.8.2.2 Plating
4.8.3 Field-applied finishes
4.9 Raceway system requirements
4.9.1 General
4.9.2 Conduit system requirements
4.9.2.1 Design
4.9.2.2 Sizing
4.9.2.3 Seismic loading
4.9.2.4 Compliance
4.9.2.5 Flexible metal conduit
4.9.2.6 Welding of conduits
4.9.2.7 Metallic conduit system
4.9.2.8 Embedded conduit
4.9.2.8.1 Embedded conduit protection
4.9.3 Cable tray system requirements
4.9.3.1 Cable tray design
4.9.3.2 Cable tray protection
4.9.3.3 Cable tray utilization #
4.9.3.4 Grounding
4.9.3.5 Flexible connectors
4.9.4 Wireway system requirements
4.9.4.1 Extent of permission
4.9.4.2 Supports
4.9.4.3 Pass-through
4.9.4.4 Extension
4.9.4.5 Grounding
4.9.5 Underground duct system requirements
4.9.5.1 Duct banks
4.9.5.2 Duct banks protection
4.9.5.3 Sloping
4.9.5.4 Duct length and configuration
4.9.5.5 Duct spacing
4.9.5.6 Metallic ducts
4.9.5.7 Ground wire
4.9.5.8 Damage
4.9.5.9 Underground raceway identification
4.9.5.10 Duct bank encasement
4.9.5.11 Reinforced concrete encasement
4.9.5.12 Sand-encased duct banks
4.9.5.13 Duct bank protection
4.9.5.14 Buried conduits
4.9.5.15 Design
4.9.6 Combination support requirements
4.10 Structural design criteria
4.10.1 Loads and load combination
4.10.1.1 Loads
4.10.1.1.1 Dead loads (DL)
4.10.1.1.2 Live loads (LL)
4.10.1.1.3 Thermal loads (T)
4.10.1.1.4 Safety relief valve loads (SRV)
4.10.1.1.5 Operating basis earthquake loads (OBE)
4.10.1.1.6 Safe shutdown earthquake loads (SSE)
4.10.1.2 Load combinations
4.10.1.3 Abnormal loads
4.10.2 Structural acceptance criteria
4.10.2.1 General
4.10.2.2 Displacement limits
4.10.2.3 Testing
4.10.3 Structural analysis
4.10.3.1 General
4.10.3.2 Dynamic analysis
4.10.3.3 Static-load analysis
4.10.3.4 Damping
5 Qualification methods
5.1 General
5.2 Analysis
5.3 Dynamic testing
5.4 Combined analysis and testing
5.5 Seismic experience based qualification
5.6 Acceptance criteria
6 Installation
6.1 Packaging, shipping, receiving, storage and handling
6.2 Installation of raceway systems
6.2.1 Supports
6.2.2 Anchorage locations
6.2.3 Conduit attachments
6.2.4 Installation requirement for fasteners
6.2.5 Preventing piping or duct failures
6.2.6 Welding
6.2.7 Painting
6.2.8 Embedded conduit, joints and fittings
6.2.9 Burrs or sharp edges
7 Documentation
7.1 General
7.2 Design activities
7.3 Raceway system components
7.4 Construction activities
7.5 Document collection, storage and maintenance
ANNEX
A Abbreviations and acronyms
B Bibliography
C Additional design considerations (Annex to 4.9 and 4.10)
C.1 Raceway systems
C.1.1 General
C.1.2 Conduit and underground duct systems
C.1.2.1 Conduit application recommendations
C.1.2.2 Conduit installation recommendation
C.1.3 Cable tray systems
C.1.3.1 Cable tray installation recommendation
C.2 Structural design considerations
C.2.1 Testing
C.2.2 Equivalent static-load analysis
C.2.3 Damping
D Guidance for acceptance criteria
D.1 Structural acceptance criteria
D.1.1 General
D.1.2 Allowable stresses and loads and the elastic stress
        design method
D.1.2.1 Raceways (except cable trays) and supports
D.1.2.1.1 Normal and severe environmental loads
D.1.2.1.2 Extreme environemental loads
D.1.2.2 Cable trays, raceway fittings, and accessories
D.1.2.2.1 Normal and severe environmental loads
D.1.2.2.2 Extreme environmental loads
D.1.2.3 Fastening devices
D.1.2.3.1 Normal and severe environmental loads
D.1.2.3.2 Extreme environmental loads
D.1.2.4 Welds, bolts and threaded parts
D.1.2.4.1 Normal and severe environmental loads
D.1.2.4.2 Extreme environmental loads
D.1.2.5 Concrete expansion anchors
D.1.2.6 Reinforced concrete structures
E Seismic experience based qualifications
E.1 Introduction
E.2 New installations (Design-by-rule)
E.2.1 Introduction
E.2.2 General requirements
E.2.2.1 Codes and standards applicability
E.2.2.2 Proximity interactions
E.2.2.3 Differential displacement
E.2.2.4 Protection of cable insulation
E.2.2.5 Cable fill
E.2.2.6 Applicability: range of seismic excitation level
E.2.3 Raceway support requirements
E.2.3.2 Conduit support locations
E.2.3.3 Connectors
E.2.3.4 Support for fittings
E.2.3.5 Support capacity
E.2.3.5.1 Dead load check
E.2.3.5.2 Vertical 4*ZPAh *DL and 3 *DL check
E.2.3.5.3 Ductility check
E.2.3.5.3.1 Ductile supports
E.2.3.5.3.2 Non-ductile supports
E.2.3.5.4 Lateral load check
E.2.3.5.5 System hard spots
E.2.3.5.6 Floor mounted supports
E.2.3.6 Supporting anchorage
E.2.3.7 Clip angle fatigue
E.3 Modification of existing installations

Gives requirements for the design, installation and qualification of raceway systems for Class 1E circuits external to electric equipment and components for nuclear power generating stations.