IEEE 628-2020 pdf download

IEEE 628-2020 pdf download.IEEE Standard Criteria for the Design, Installation, and Qualification of Raceway Systems for Class 1E Circuits for Nuclear Power Generating Stations.
Zinc plating: ASTM B633, Coating Class FE/ZN5 Cadmium plating: ASTM B776, Coating Class TS
4.8.2 Field-applied finishes
Field-applied finishes shall be compatible with the finishes applied during the manufacturing process.
4.9 Raceway system requirements
Raceways entering enclosures from the top or sides shall be designed to reduce the entrance of condensation or water and to prevent the accumulation of moisture within the equipment. The necessity for equipment drains or conduit seals shall be predicated on the required environmental parameters of the equipment contained in the enclosure. See IEEE Std 690 for raceway fill requirements. Raceways shall not be connected to the top or sides of electrical equipment unless accounted for in the design.
4.9.1 Conduit system requirements
4.9.1.1 Design
Conduit systems shall be designed and arranged with suitable pull points (such as boxes and manholes) and bend radii so that the allowable cable pulling tensions and side-wall pressures recommended by cable manufacturers or determined by calculation are not exceeded (see IEEE Std 690).
4.9.1.2 Sizing
Conduit shall be sized to avoid critical jamming ratio diameters (see IEEE Std 690).
4.9.1.3 Seismic loading
Unlessjustification is otherwise provided, rigid metal conduit (RMC) or IMC5 shall be used in exposed conduit
systems designed for seismic loading.
4.9.1.4 Compliance
Where compliance is required by local, state, or federal laws, the National Electrical Cod& (NEC)
(NFPA 70) shall be used in selecting conduit types for use in hazardous locations.
4.9.1.5 Flexible metal conduit
The length and installed configuration of flexible metal conduit shall be designed to provide for dynamic and thermal movement and to accommodate the largest minimum bending radius of the cables to be installed. The length of flexible metal conduit shall be accounted for in the design and qualification of the conduit system. Flexible entry shall be used for conduit entering Class 1 E equipment where relative movement between the conduit and the equipment is anticipated.
4.9.1.6 Welding of conduits
Welding of conduits shall not be permitted.
4.9.1.7 Metallic conduit system
The entire metallic conduit system, whether embedded or exposed. shall be electrically continuous and grounded in accordance with IEEE Std 665. Where used as the equipment grounding conductor, flexible conduit and associated fittings shall be suitable for the anticipated ground fault current, or they shall be paralleled with a ground cable of suitable size.
4.9.1.8 Embedded conduit
Embedded conduit may be either metallic or nonmetallic. When embedded in building walls or floors, it shall meet the requirements ofACI 349/349R, unlessjustification is otherwise provided. Embedded conduit subject to flooding shall slope either to boxes, handholes, or manholes for drainage or be sealed to exclude the entry of water. Where embedded conduit crosses a seismic, vibration, or expansion/contraction joint, a piece of flexible conduit or suitable fitting shall be installed to allow relative movement of the structures without damaging the conduit.
4.9.1.9 Embedded conduit protection
Protection shall be provided for embedded conduit at floor levels and other locations where physical damage
to cables is likely.
4.9.2 Cable tray system requirements
4.9.2.1 Cable tray design
Cable trays shall be designed to carry their design dead load (DL) (see 4.10.1.1.1) and a minimum concentrated load of 90.7 kg (200 lb) at midspan at the centerline of the tray or on either side rail. Under this condition, the tray shall neither fail nor be permanently distorted.
4.9.2.2 Cable tray protection
Protection shall he provided on exposed vertical tray risers at floor levels and other locations where physical damage to cables is likely.
4.9.2.3 Cable tray utilization
Cable trays shall not be utilized to carry ducts, piping, instrument tubing, or other equipment unless it can be demonstrated that the Class 1 E functions of the cables will not bc degraded below an acceptable level.
4.9.2.4 Grounding
Cable tray systems shall be electrically continuous and solidly grounded. Where the tray is not capable of serving as an adequate ground return path, a ground conductor of suitable size shall be attached to and run parallel with the tray.