Section 13 — Electrical

Electrical Equipment Shelters

IPE Engineering Practice IPE-EP-13-16-1

Document number: IPE-EP-13-16-1 · Section: 13 — Electrical

SCOPE

• This Practice describes the general requirements for a prefabricated, modular type, self– contained, self–supporting frame shelter for housing electrical/electronic equipment.
• This Practice is appropriate for attachment to an inquiry or purchase document when accompanied by the referenced IPE Engineering Practices and completed Data Sheets per EP 13–16–1 DS.
• Any deviation from this Practice must be approved by the procedure described in EP 1–1–3.
• A revision bar indicates all changes made to this Revision.

2.0 REFERENCES

All applicable sections of the latest standards and codes listed below are a part of this Practice for design, construction and testing unless amended herein. It shall be the Manufacturer’s responsibility to be or become knowledgeable of the requirements of the standards and codes. Any changes or alterations to the equipment to make it meet the requirements shall be at the expense of the Manufacturer.

STANDARDS AND PUBLICATIONS

STANDARDS AND PUBLICATIONS (CONT.)

3.0

3.1

3.2

3.3

3.4

3.5

3.6

4.0

5.0

5.1

5.1.1

5.1.2

DEFINITIONS

Contractor – Company or business that agrees to furnish materials or perform specified services at a specified price and/or rate to the Owner.

Inspector – A Inflection Point Engineering, LLC appointed engineer or inspector.

Manufacturer – The recipient of a direct or indirect purchase order for materials and/or equipment. In this context, a direct order is one issued to a Manufacturer by a Contractor or the Owner. An indirect order is one issued to a Manufacturer by a vendor (recipient of a direct order) for materials, fabricated components, or subassemblies.

Owner – Inflection Point Engineering, LLC .

Owner’s Engineer – A Inflection Point Engineering, LLC appointed engineer.

Purchaser – The party placing a direct purchase order. The Purchaser is the Owner’s designated representative.

SERVICE CONDITIONS

The electrical equipment shelter (EES) shall perform satisfactorily when installed outdoors in an atmosphere typical of petrochemical plant. Unless otherwise specified on the Data Sheets the EES shall be installed in a 104ºF maximum ambient, –15ºF minimum ambient, and at an elevation below 3,300 feet.

DESIGN, CONSTRUCTION AND MATERIALS

General

The EES approximate dimensions and preliminary layout will be as shown on the Data Sheets and associated inquiry drawings/documents.

The EES is a fabricated metal environmentally controlled enclosure that is specifically designed to house selected electrical/electronic equipment. The following electrical/electronic equipment is typical of what may be included in an EES:

• Medium voltage switchgear
• Low voltage switchgear
• Motor drive systems
• Medium voltage motor controllers
• Low voltage motor control centers
• Grounding resistors
• Distribution transformers
• Lighting and distribution panelboards

• Batteries and battery chargers
• Uninterruptible power supply (UPS) systems
• Control switchboards
• Supervisory control systems
• Protective relaying panels
• Annunciator and alarm panels
• Communications panels
• Instrumentation packages
• Computer/Distributed control system equipment
• Each EES will rest on either a concrete pad, stem wall, or piers at the installation site. The structural frame of the building’s base, however, shall be self supporting.
• The EES shall maintain a controlled environment and endure the prevailing climatic, and petrochemical conditions at the installation site.
• The EES shall be dust–tight and weatherproof and shall not leak wind driven rain, sleet or snow.
• If shipping splits are required every effort shall be made to minimize splits under electrical equipment.
• If the enclosure is a split design, the fabricator shall provide all of the interconnection diagrams required for internal and external wiring across shipping splits.
• Base
• The steel supporting base shall be fabricated from standard AISC shapes using ASTM A36 steel. The base design shall be sized and arranged for proper strength and durability to withstand the loads/forces resulting from shipping and lifting the completely assembled structure with equipment in place. Deflection during lifting shall not exceed 0.25 inches per 10 feet.
• All base members shall be joined by continuous weld.
• The location of base structural members and recommended pier locations shall not interfere with or obstruct the areas designated for routing of power cables.
• The base shall have four removable lifting/jacking devices attached to and extending beyond the parallel to the base perimeter. The normal lifting for transportation and installation shall be by means of a crane making a single point lift using suitable rigging.
• The base shall have two (2) or more grounding pads, each with four (4) threaded holes, located at opposite ends of the EES.
• Floor
• The floor plate shall be a minimum 3/16 inch ASTM A36 steel material firmly welded to the base. The floor loading design shall be rated not less than 200 pounds per square foot.
• Outgoing/incoming cable and/or conduit locations shall be provide per the electrical equipment Manufacturer’s requirements, the Data Sheets, and or contract documents. A cut out with a gasketed cover plate shall be provided for all conduit and/or cable locations including future equipment. Unless specified otherwise, cover plates shall be top removable with hold down screws that are also top removable.

• The floor shall be sufficiently flat (free from bows, warps, protrusions, and ridges) to provide stable support for the equipment bases as well as a smooth walking/rolling surface. There shall be no visible joints in the floor except at the shipping break.
• Walls
• Exterior Walls
• Exterior walls shall be either paintable galvanized steel sheets conforming to ASTM A527 and G90 coating or galvannealed steel sheets with coating weight of A60. In either case, the steel shall be 18 gauge minimum. Alternative materials may be quoted in addition to that specified for review and approval by the Owner.
• Unless specified otherwise, exterior wall panels and framing shall be designed to withstand wind loadings of up to 125 miles per hour.
• Exterior wall panels shall be 107 inches high, or higher, as measured inside from the floor to its juncture with the ceiling.
• Exterior walls behind switchgear shall have hinged door panels (double doors for two high medium voltage switchgear) for complete access to equipment. Three point door latches and lockable door handles shall be provided for each door.
• Interior Walls (wall liner)
• Interior walls shall not be the same galvanized sheet steel as described in paragraph

5.4.1.1 of this Practice except the steel shall be 18 gauge minimum. Alternative materials may be quoted in addition to that specified for review and approval for use by the Owner.

• Wall thickness shall not be less than 3 inches nor more than 3–1/2 inches.
• Interior wall panels, trim, etc. shall be welded or screwed in place. Glues, epoxies, or rivets shall not be used for securing panes and trim.
• Interior wall panels supporting wall mounted equipment shall be designed or modified to provide stable support for the load without compromising the 125 mph design wind loading.
• Exterior and interior wall panels shall be a single continuous length from the base channel to the roof line of the building at the sidewalls and endwalls of the building, except where interrupted by wall openings.
• Unless specified otherwise, end wall construction shall permit removal and replacement for expansion of the building at both ends.
• Cut outs for equipment mounted through the wall shall be framed and reinforced to support the equipment. In addition proper shielding shall be provided to prevent rain and snow from entering the building.
• Equipment access doors provided for future equipment shall have the interior of the door insulated and covered with a removable sheet steel panel. The panel shall prevent entry from the outside of the EES. The panel shall be painted the same color as the interior walls.
• Roof and Ceiling
• The exterior of the roof shall be 16 gauge or thicker sheet steel panels of paintable galvanized steel conforming to ASTM A527 with a G90 coating or galvannealed steel sheets with a coating weight of A60. Alternative materials may be quoted in addition to that specified for review and approval by the Owner.
• For panels requiring fastening at intermediate points along the panel joints, the design shall have the panel side flanges formed upward with a rain guard (cap) covering the joint of two panels. Bolts and nuts shall be used to secure roof panels together.

• Roof panels shall be supplied in a single continuous length from eave line to ridge line (eave to eave line for one way sloped roofs).
• The roof design shall not have weather exposed fasteners nor rely on any type of taping and/ or caulking as a primary means of weather sealing.
• The building roof shall not be flat. A minimum slope of two (2) degrees (pitch) shall be employed to insure adequate drainage. Shelters with flat sloped roofs shall have the roof pitch toward the side not having a bus duct entrance.
• Unless the location of the shelter would require a higher load factor (heavy snow loading), the roof shall be designed to carry a minimum load of 50 psf.
• The ceiling shall be 18 gauge or thicker steel sheets conforming to Paragraph 5.4.1.1 of this Practice. The ceiling shall be designed to retain insulation and provide a smooth surface. Paragraph 5.4.1.2 of this Practice shall apply concerning the fastening of panels to adjacent panels and to roof trusses.
• Aluminum rain gutters with down spouts (to grade i.e., including shelters on piers) shall be provided.
• Doors
• The EES shall have two (2) personnel doors, one at each end. Unless specified otherwise, one door shall be 36 by 84 inch and the other door 42 by 84 inch. Both doors shall have removable wall sections above the doors to increase the door opening to a minimum height of 94 inches.
• All doors shall swing a minimum of 105 degrees and shall open outwardly.
• Each door shall be pre-assembled into a welded steel frame. Hinges shall be type 304 or 306 stainless steel, 10 gauge minimum, with 1/4 inch diameter fixed pin. Three or more 4 inch by 4 inch hinges shall be used and the hinge leaves shall be mounted such that they are perpendicular to the face of the door when it is closed. The door shall be positioned in the frame and gasketed to provide a positive seal against wind–driven rain when closed.
• Unless specified otherwise on the Data Sheet, entrance doors shall be of galvanized steel, double wall construction, containing fire resistant insulation. Each door shall be of uniform thickness, free from warps, bows and bulges and shall have sufficient rigidity to maintain a positive seal when closed.
• A panic bar assembly and a heavy duty automatic door closer shall be furnished on the interior of each door. A ll hardware, interior and exterior, shall be of industrial quality stainless steel. This shall include screws, latches, latch strike plates etc.
• Equipment access doors shall be fabricated from 10 gauge galvanized steel sheets with galvanized sheets conforming to ASTM A526 and minimum coating G90 or galvanneal with a minimum coating of A60.
• Equipment access doors shall be hinged, gasketed, have 3–point latches, and have handles with provision for locking with a padlock. The door handle shall be either stainless steel or copper free aluminum.
• A large removable rain guard (awning) shall be provided above each personnel door and each equipment access door.

• Equipment access door louvers shall be screen and/or filtered to prevent entrance of insects and dust.
• Painting
• If the following paint system is not the fabricator’s standard, the fabricator shall submit complete details/specifications for their paint system for approval by the Owner. However, every effort shall be made to provide a paint system that meets or exceeds the specification in this Practice.
• Base: The system shall incorporate 4 separate phases as detailed below:
• All structural framing members shall be cleaned by sand blasting until free of scale and rust. The use of chemical or solvent cleaning of structural steel shall not be permitted.
• After cleaning via sandblasting the base shall be painted with a quality primer that will be compatible with the finish coat. A typical primer would be a zinc chromate red oxide type. Dry film thickness shall be 2.5 to 3.5 mills as a minimum.
• After priming a final coat of an epoxy (catalyst epoxy) shall be applied over the entire base. Dry film thickness shall be 2 to 3 mills as a minimum.
• The underside of all EES bases shall be coated with corrosion resistant mastic material such as 3M Co. #1000.
• Exterior walls and roof panels (galvanized/galvannealed steel) the painting system shall consist of three basic phases as detailed below:
• Metal preparation shall include suitable cleaning and degreasing. The final chemical treatment shall be with an iron phosphate metal conversion rinse solution followed by cleanwater rinsing. The metal preparation shall be compatible with the galvanized steel used and the Manufacturer’s recommendations.
• The second phase shall be the application of a primer compatible with the finish coat.
• For a polyurethane finish coat a polyester primer shall be applied and oven cured. Finish dry coat shall be 2 to 4 mills thick.
• For an industrial acrylic enamel finish coat a zinc chromate red oxide prime shall be applied, with minimum coating of 3 mills.
• The finish coat shall be either a polyurethane product or an industrial exterior acrylic enamel. In either case, the final color required for exterior walls and roof is white. The polyurethane coat thickness shall be 1.0 to 1.5 mills, the enamel shall be 3 mills thick or greater.
• Interior walls and ceiling: The interior walls shall be cleaned, primed, and painted by the same methods and with the same materials as the exterior walls, see paragraph 5.7.3 of this Practice. The interior walls and ceiling color shall be white.
• Floor: The floor shall be thoroughly cleaned, epoxy primed, and coated with a gray non–skid, scuff resistant epoxy or urethane coating.
• Insulation
• Walls and Ceilings
• The walls and ceilings shall be insulated with fiberglass insulation having a minimum of R–11 insulating value. Removable access panels above doors shall be insulated.
• Equipment doors for future equipment shall be insulated and have a removable sheet steel cover over the insulation on the interior side.
• Suitable retaining ridges or other methods shall be employed to keep wall insulation from slipping down and compacting at the bottom of the wall.

• Floor Insulation
• Underfloor insulation is required.
• The preferred underfloor insulation is a 3 to 4 inch thick spray on foam insulation that will result in an R–11 insulation value.
• If the underside of the floor is insulated with batts of loose insulation, the underside of the floor base shall be covered with galvanized sheet steel to keep floor insulation in place. The exposed underside steel sheet shall be treated per paragraph 5.7.2 of this Practice.
• Facilities
• Lighting
• Interior lighting shall be furnished installed. The lighting shall include energy efficient fluorescent lighting fixtures, lamps and a three–way spec.grade switch at each end of the shelter located at the door. The minimum illumination levels shall be 50 foot candles of lighting at a level of three feet above the floor and 40 foot candles on the vertical face of each piece of equipment in the shelter. Lighting shall be mounted over the workbench (see paragraph 5.9.5 of this Practice) and provide a minimum of 60 foot candles of lighting level at the workbench level. Workbench lighting shall be switched by a separate light switch from the general interior lighting. Locate the workbench light switch in an accessible location next to the workbench.
• Emergency lighting shall be provided above each exit door. The lighting shall be from self contained battery powered units with two illuminating heads per unit. The unit shall switch on automatically upon loss of shelter (facility) AC power and provide a minimum of one hour of continuous illumination.
• Exterior lighting shall be provided at each entrance door, other exterior lighting shall be supplied, as specified. The lighting shall be high–intensity discharge type (HPS) and shall be suitable for the area classification specified. They shall be controlled by a photo–cell (provided with EES), as well as by a switch inside the shelter. The switch shall be a maintained, three position, UL listed heavy duty industrial grade, on–off–auto. The EES builder shall provide the complete external lighting system with the entire installation and equipment suitable for the specified area classification.
• EES Electrical Distribution
• 20 ampere, 120 volt spec. grade duplex receptacles shall be provided on the wall in the maintenance area, near the light switch at each entrance door and outside the EES located at each end of the EES near the base. The exterior outlets shall be ground fault protected and enclosed in a suitable exterior enclosure.
• An AC electrical distribution panel (GE or Square D) shall be provided that is of appropriate rating to source all the required substation and EES loads. Substation electrical loads shall be identified on the Data Sheet and/or other contract documents. The minimum size panel shall be a 24 circuit panel with a main breaker.
• HVAC and Pressurization
• Electrical heating and air conditioning system shall be provided for all EES. The system shall be sized and provided by the EES fabricator. The system shall automatically maintain the interior temperature to a maximum of 80 ºF and a minimum of 68 ºF for the given ambient site conditions and the insulation provided for the EES.

• The HVAC temperature controller shall be a single unit with manual selection of heating or cooling.
• It shall be the EES fabricator’s responsibility to determine the maximum heat load of the equipment supplied including identified futures and calculate the HVAC system requirements. All calculations and equipment heat loads shall be provided to the Owner’s Engineer for review with the quotation and then again with the for approval documents prior to fabrication.
• All exterior copper and brass components of the HVAC system shall be coated with Herisite or equivalent to protect the copper parts from H2S and other similar chemicals found in a petro–chemical plant. Alternatives to this would be stainless steel or copper free aluminum components/parts.
• Pressurization
• When specified on the Data Sheet, EES pressurization shall be provided in accordance with NFPA 496 to achieve a general purpose shelter classification.
• In addition to the requirements of NFPA 496, the system shall include a visual/scaled pressure indicating device and an adjustable time delay to alarm system. Alarm contacts provided shall be rated 125 VDC, 5 ampere or higher.
• When specified, the intake system shall include filter (or scrubber) as required for the materials identified .
• The intake air stack height shall be as specified on the Data Sheet.
• Work Area
• Unless specified otherwise, an area for light maintenance shall be provided in the EES.
• The work area shall be provided with a commercially available workbench with a wooden top, minimum size shall be 30 inches by 48 inches.
• Space shall also be provided for a standard 4 drawer filing cabinet to be provided by others.
• DC System
• When a DC stationary battery and charger system is specified with the EES, it shall comply with EP 13–19–1 and the associated Owner approved Data Sheets. Acceptable vendors shall be only those specified by the Owner.
• A DC panel board shall be provided for DC power distribution. A minimum of 12 circuits shall be provided.
• An OSHA approved, wall mounted, self contained eyewash shall be provided and mounted on a wall adjacent to the batteries.
• A metal enclosure with hinged access door shall be provided to enclose the batteries. In addition a vent fan shall be provided to remove hydrogen from the enclosure and vent to the exterior of the EES.
• The entire floor area of the enclosure under the battery shall have a stainless steel drip pan to catch acid liquid that may leak from the battery system.
• Station Service (Power) Transfer Switch

When a 120/240 volt or 120/208 volt station power transfer switch is required it shall be a linear actuator type switch that fully complies with EP 13–19–1 and the associated Owner approved Data Sheet.

• Wiring
• Wiring for building facilities such as lighting, HVAC etc., shall be in EMT or RGS conduit and be segregated from all other wiring.
• All equipment interconnecting wiring shall be in rigid galvanized steel conduit. The conduit shall comply with ANSI C80.1 and UL–6. The use of wire ways, wiring troughs, etc. shall only be used when approved by the Owner.

• Flexible conduit, if used, shall be UL listed and comply with UL–1. Grounding of flexible conduit shall comply with NFPA 70.
• All facility and equipment interconnecting power and control wiring in the EES shall be done by the EES fabricator.
• All lighting, power, control and alarm wiring shall be 600 volt, stranded copper, 90ºC rated, moisture and heat resistant XHHW, XHHW2, or SIS insulated.
• Compression lugs shall be insulated barrel type with spade termination. Ring tongue type shall be used for all CT wiring.
• Both ends of each interconnecting wiring shall have permanent plastic sleeve type wire marks. All wire marks shall be in accordance with the interconnection wiring diagrams.
• Equipment (e.g. switchgear) wiring requirements shall be as directed in the applicable

IPE Engineering Practice. The minimum wire sizes shall be as follows:

• Lighting and power No. 12 AWG
• Control and alarm No. 14 AWG
• DC power to equipment No. 8 AWG
• DC power in equipment No. 10 AWG
• Wireways shall not be used, unless use is approved by the Owner. Wireways when specified, shall comply with the following.
• Wireways shall be fabricated from 16 gauge or heavier steel and shall be designed such that there are no raw metal edges in or along the duct.
• Wiring shall not occupy more than 20 percent of the total cross sectional area of any duct.
• Each wireway shall have a screw mounted cover plate.
• Grounding
• The grounding system for the equipment shall use a single point grounding system. The single point ground shall be a copper ground bar 1/4 inch by 2 inch wide, a minimum of 18 inches long. All equipment ground buses shall be connected to this as well as the building frame using 2/0 stranded copper wire. Facilities equipment shall also be grounded to the ground bus using stranded copper wire sized per the NEC. All internal equipment ground buses shall be connected together to form a continuous ground path/loop.
• For equipment with ground connections at each end of the ground bus separate wires shall be run to the ground bus. Daisy chaining of grounds between equipment shall not be permitted.
• Separate 2/0 AWG ground wires shall be run from the ground bus to each EES frame ground pad.

INSPECTION AND TESTING

• Inspection

The Owner shall have the right to inspect the EES and equipment being installed in the EES during the manufacturing and equipment installation prior to shipment.

• Testing
• EES and Facilities Testing: After assembly of the EES and installation of all facilities and equipment are completed the following checks/tests shall be performed.
• Perform continuity checks of all wiring installed by the EES fabricator.
• Verify grounding of all equipment in the EES.
• Inspect and verify operation of all lighting, lighting controls and receptacles.
• Verify, by operation the following equipment.
• HVAC system(s)
• Air pressurization system(s)
• Annunciator system
• EES fabricator installed electrical equipment
• All the electrical equipment installed in the EES shall be tested as detailed in the IPE Engineering Practice and associated Data Sheet for the specific equipment. Testing of the electrical equipment shall be performed after it is completely installed in the EES.
• If a subcontractor and/or the EES Manufacturer is used to perform the tests, the subcontractor and/or the EES Manufacturer must be approved by the Owner.
• Witness Test

When witness testing is specified, the Owner shall witness the complete test as specified on the EES and equipment Data Sheets as well as any additional requirements of the contract documents.

DRAWINGS AND DATA

The drawings and data required shall show the equipment as ordered and built. Typical drawings are not acceptable, unless revised to show as–built equipment ordered. Owner’s name, job number, P.O. number and item number shall accompany all drawings and data. Data shall be supplied in the format and quantities specified on the Data Sheet and Table 1.

• Data to be Supplied with Quotation (refer to manufacturer document requirements in the requisition for additional requirements)
• Exceptions to this Practice.
• Details on alternate designs proposed, complete with typical construction drawings, bill of material and descriptive literature.
• Any suggested changes in equipment arrangement affording a space or cost savings.
• Overall dimensions and weight of each EES. A complete description of all equipment to be provided as well as the Manufacturer, including equipment arrangement, power supply requirements for building services, etc.
• Price addition or deletion for adding or deleting the following:
• Each 12 inches of building
• Each 24 inches of building
• Each 36 inches of building

• All data required by other specifications pertaining to the equipment to be installed in the building. Calculations to demonstrate capability of the HVAC system offered to meet the requirements of this Practice.
• A listing of all equipment requiring field installation.
• Drawings and Data to be Submitted for Owner Approval after Receipt of Order
• Foundation plan for each EES showing recommended location and maximum size of openings under each structure for cable entrance.
• Outline drawing for each EES giving total weight and showing overall dimensions and the location and details of bus duct connections as well as the location of the shipping split and lifting ears for each section. Recommended pier locations and pier loadings shall be given on drawings for pier mounted EES.
• Assembly drawing complete with detailed bill of material showing the equipment and its arrangement.
• Structure drawing(s) for each EES showing the details of construction of the base, its members and supports, as well as construction details on the following:
• Exterior and interior wall panels
• Roof panels
• Wire ducts
• Doors
• All data required by other IPE Engineering Practices pertaining to the equipment to be installed in the EES.
• Electrical interconnection diagrams.
• EES rigging and lifting details.
• Certified Information to be Supplied
• The drawings and reproducibles for each building as outlined in 7.2 above in the quantities specified on the Data Sheet.
• Installation, operation and maintenance manuals for each building and its facilities in the quantity specified on the Data Sheet. One set shall accompany each building.
• Spare parts list.
• Test/inspection reports for all tests required in paragraph 6.0 of this Practice and as specified in the contract documents.

SPARE PARTS

A complete spare parts recommendation based on the total purchase order is required within 30 days after the Manufacturer receives the purchase order. Spare parts recommendations shall include:

• A complete spare parts list, including parts location diagrams of drawings.
• Lists of priced spare parts as recommended by the Manufacturer to be on hand during start–up and the first year’s operation.

SHIPPING

• When shipping sections are necessary, the open area of each section shall be sealed with plywood and 2 x 4’s, and provided with adequate temporary bracing for the roof and wall structure to prevent damage during shipment.
• Equipment provided in the EES shall be prepared for shipment in accordance with the Manufacturer’s recommendations.
• All loose and removed items shall be properly identified and packaged for temporary outdoor storage. Items requiring indoor storage will be identified and instructions for storage provided.

10.0 TABLES

TABLE 1 DOCUMENTATION REQUIREMENTS FOR ELECTRICAL EQUIPMENT SHELTERS PER EP 13–16–1

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