Table of Contents
| Section | Title | Page |
| Purpose | 2 | |
| Scope | 2 | |
| Related Documents | 2 | |
| Checklist Criteria | 3 | |
| Typical Drawing Presentation Checklist Items | 3 | |
| Change Log | 3 | |
| Cover Sheet Checklist | 4 | |
| Single Lines Sheet Checklist | 5 | |
| Schematics Checklist | 6 | |
| Physicals Checklist | 7 | |
| Wiring Diagram and Conduit/Cable Schedule Checklist | 11 | |
| Underground Checklist | 12 | |
- PURPOSE
1.1 This engineering guideline provides checklists that can be used for reviewing Electrical Design drawing packages.
- SCOPE
2.1 This checklist should be used when reviewing all Electrical Design drawing packages developed for Air Products-owned and -operated facilities. This checklist may also be useful when designing third-party and sale of equipment facilities; however, customer’s requirements need review before proceeding with facility design.
2.2 Related documents listed in Section 3 but not referenced in the text provide additional background information.
- RELATED DOCUMENTS
3.1 Air Products Engineering Documents
3ES80101 Risk Management of Hazards in Equipment Enclosures That Can Be Entered by Personnel
3EL61001 Single Line Diagram Drawing Content
4EL63007A Control Systems Design Criteria
4EL64127A Terminal Boxes
4EL64226A Emergency Stop Stations
4EL64327A Electrical Heater Terminations
4EL64352A Substation/Plant Grounding Practices
4EL64353A Equipment Grounding
4EL64401A Electric Heating for Cryogenic Equipment Foundations
4EL64430A Emergency Lighting Systems
4EL64501A Panelboards
4EL64552A Spacing Criteria for Indoor Electrical Equipment
4EL64577A UPS Systems and Regulating Transformers Design and Installation Requirements
4AEL-620300 Electrical Work
4AEL-620301 Hazardous Area Requirements for Class I Areas
4AEL-620302 Standard Wire and Cable Types
4AEL-620303 Installation and Testing of Medium Voltage Cable
4AEL-620304 Electrical Underground Work
STD-G313A Grounding – Foundation Reinforcing Bar
STD-P315A Power & Control Conduit Stub-Up Details (3 sheets)
STD-P316D Typical Electrical Installation Practices Around Machinery
STD-P326A Motor Terminal Box – Installation Details
STD-P329A Bus Duct Support Detail
STD-P338A Low Point Drain Installation Details (2 sheets)
STD-P331A Cable Tray Supports (4 sheets)
STD-S305A Symbols – Schematic & Wiring Diagrams
STD-S306A Symbols – Single Line Diagrams/Schematic & Wiring Diagrams
3.2 National Electrical Manufacturers Association (NEMA)
VE-1 – Metal Cable Tray Systems
3.3 National Fire Protection Association (NFPA)
70 – National Electrical Code (NEC)
- CHECKLIST CRITERIA
4.1 Checklist items for single lines and schematics (Appendixes B and C) include both standards and requests by the Global Support Services (GSS) Electrical Engineering Department. The Electrical Design package checklists for physicals and wiring diagrams (Appendixes D to F) are based on issues identified from field construction sites, construction change orders (CCOs), and punch list items from previous projects; however, many design and engineering standards and guidelines are also identified.
4.2 These checklists were developed to keep designers aware of field issues experienced on completed projects in an effort to avoid repeating the same issues on future Electrical Design packages.
- TYPICAL DRAWING PRESENTATION CHECKLIST ITEMS
5.1 Title Block: Information in the title block shall include the standard first line title taken from the Standard Deliverable list located in STAC, be consistent for all electrical drawings and be consistent with other disciplines working on the project.
5.2 Drawing Numbers: Drawing numbers and electronic file names shall match on each document. Drawing numbering shall be developed as identified in the Standard Work Process for Numbering Documents in STAC.
5.3 North Arrows: Put facility directional arrows (generally North arrows) on all physical drawings. When separate physical plans are located on the same drawing and are rotated in different directions, put directional arrows on each plan.
5.4 Visual Scales: All plan drawings shall have the scale identified in the title block and a visual scale on the plan. With the removal of the drawing size and current use of electronic bid packages, it is impossible to determine what size paper the contractors will print the drawings on. A visual scale is the only way to verify the scale used by the contractor is correct to the drawing size printed.
Appendix A
Cover Sheet Checklist
A1. Panel Legend and Terminal Block Legend Symbols should match symbols used on control schematics. Use standard cover sheet or Standard Drawing Symbols drawings (STD-S305A and STD-S306A) when applicable and add or delete symbols as required.
A2. High Voltage Single Line Symbols should match symbols used on single line diagrams. Use standard cover sheet or Standard Drawing Symbols drawings (STD-S305A and STD-S306A).
A3. 480 Volt Single Line Symbols should match symbols used on single line diagrams. Use standard cover sheet or Standard Drawing Symbols drawings (STD-S305A and STD-S306A).
Appendix B
Single Lines Sheet Checklist
B1. Content and presentation of single line drawings shall be per the requirements of 3EL61001. These requirements are not repeated here.
B2. When adding equipment or plants to existing facilities ensure the ‘Facility Overall Single Line Diagram’ is updated to reflect the new equipment. All existing detailed single lines shall be updated where functionally associated.
B3. Approval of drawings by the projects Electrical Engineer.
B4. On multiple plant facilities when more than one main plant power source exists, 480 volt sources for compressor auxiliaries (e.g., pumps, heaters) must be derived from the same main plant power source that serves the associated high voltage (HV) compressor motor.
B5. 480 volt fuses serving motor loads should be time-delay type and sized using fuse manufacturers sizing chart for Motor Overload Protection. Fuse sizing shall be based on motor nameplate horsepower.
B6. Review DCS and instrumentation power requirements with Electrical and per UPS and Regulated Power Load List. See 4EL64577A.
B7. Power feeder to electric fire pump should be derived on the line side of the main 480 volt circuit breaker, wherever possible.
B8. Show motor control center front view layout on 480 volt single line diagram. Layout shall include identification of each vertical section and individual compartment.
B9. Confirm motor horsepower and Heater KW ratings with supplier documentation.
B10. Confirm standard drawing notes pertaining to contractor’s responsibilities for furnishing and installing fuses, fuse reducers and sizing and installing motor overload heaters are incorporated on drawing.
B11. Separate UPS systems are required for communications, security systems, etc. These loads shall not be powered from UPS systems used for process control.
Appendix C
Schematics Checklist
C1. Show cross-reference relay contacts on the sheet with the relay coil.
C2. Control panel designation at each device located within control panel per Panel Legend on Cover Sheet or Standard Drawing Symbol drawings (STD-S305A and STD-S306A).
C3. Control panel terminal block designations per Terminal Block Legend on Cover Sheet or Standard Drawing Symbol drawings (STD-S305A and STD-S306A).
C4. Each device or switch function shall be designated (e.g., oil, purge gas).
C5. Approval of high voltage and 480V schematic drawings by the project Electrical Engineer.
C6. For motor space heater circuits (when the motor is fed from draw out switch gear), the normally closed auxiliary contact (52b) shall be stationary mounted, not breaker mounted.
C7. Identify control power transformer sizing in VAC and fuse sizing for motor control center (MCC) starters with oversized control power transformers only.
C8. Control valve designations of fail-open (FO) or fail-closed (FC) and corresponding solenoid functional description.
C9. Required time setting ranges for all timing relays and time settings, if available.
C10. On 480 volt MCC schematics (when control power is derived externally), an auxiliary contact from the disconnect switch or breaker must be used to disconnect the remote control power source.
C11. Confirm that shutdowns listed in the beginning of the flowsheets are included in the schematics.
C12. Trailer pull away protection at loading stations shall have a dedicated rotating beacon and dedicated siren.
C13. Relay 14, motor zero speed switch circuit which initiates lock out trip, target, and alarm.
C14. Initiate meeting with Process Controls Engineer responsible for project to review facility control philosophy. Use 4EL63007A as checklist to conduct meeting.
C15. Dedicated 120 volt circuit for plant horns using interposing relay from DCS digital output (d.o.).
C16. Confirm use of latest standard control schematics.
C17. Certain instruments require external 24 VDC or 120 VAC power (e.g., level switches/transmitters with capacitance probes, vortex flow transmitters). This should be reviewed as part of discussion with Process Controls Engineer identified in C14.
C18. Confirm the excess flow requirements are addressed. Refer to 3SEA0901 for further information.
C19. Confirm solenoids are properly controlled as identified on the P&ID (e.g., energize to trip, fail open, fail closed).
Appendix D
Physicals Checklist
D1. Typical Physicals
D1.1 Uninsulated bus extensions (e.g., bus bar, tubing) from the electrical building to transformers shall run horizontally from the building wall flange at least four feet before elbowing vertically upward to the transformer bushing height for safety considerations (i.e., a person on building roof cannot reach exposed, uninsulated bus).
D1.2 Support bus duct according to manufacturer’s recommendations. Depending on building type, a support might be required inside of the electrical building at the wall flange. Refer to drawing STD-P329A for standard bus duct support detail.
D1.3 Verify drawing STD-P326A is referenced on applicable contract drawings to identify contractor responsibilities regarding installation of separately shipped medium voltage motor terminal boxes.
D1.4 Sufficient lighting to illuminate areas with manual valves and indicating instruments, particularly in the storage, expander, and mole sieve areas.
D1.5 On bottom entry motor terminal boxes, adjust leg height such that the motor throat vertical centerline is approximately at the current transformer (CT) centerline while maintaining a clearance between the throat flange and the top louvered cover for future cover removal.
D1.6 Emergency stop push-buttons where required in compressor motor area are located for convenience along path of emergency. Mounting on the stairway handrail is unacceptable. On compressor platforms, the push-button shall be located on the handrail at the top of the stairway. Push-buttons to be red jumbo, mushroom head type, with an extended shroud that positively prevents accidental operation. Refer to 4EL64226A and manufacturer’s literature for additional details. Buttons shall be mounted away from motor terminal box, preferably on the opposite side of machine.
D1.7 For buildings with a single beam crane (no platform), locate high bay overhead lighting fixtures such that fixtures can be accessed either from directly beneath with a McGill lamp changer or from a ladder placed against the crane. Buildings with double beam cranes and platforms allow access to fixtures directly from one crane and require no special attention. All lighting design and placement must be done with fixture maintenance in mind.
D1.8 Locate start/stop push-button stations for LOX cryogenic pumps between 10 and 15 feet from the pump.
D1.9 Fire pump feeder circuits shall be physically routed outside of the buildings, excluding the electrical switch gear building and pump room (where involved).
D1.10 Main breaker required on 120/240 volt and 120/208 volt panel boards. Not required for 120 volt, two wire panel boards. Refer to 4EL64501A for additional details.
D1.11 The package should include Standard Drawing STD-P316D, which shows the recommended conduit routing to avoid interferences with equipment and required vibration probe/proximitor installation for compressor/motor areas. Detail No. 10 must be referenced for all compressors requiring field installation of the proximitor and thermocouple junction boxes. Locate proximitor boxes within vibration probe lead length constraints (usually 10 to 15 feet).
D1.12 Emergency lights required in:
- All buildings for safe exit (minimum of 0.3 foot-candles).
- Control room and electrical room to secure plant (minimum of two foot-candles).
- Exit lights are required at all exits in buildings when emergency lighting is installed or where required by authorities having jurisdiction.
Refer to 4EL64430A for additional information.
Appendix D (continued)
Physicals Checklist
D1.13 Interference checks within building between:
- Lighting and HVAC ducting.
- Cable tray and HVAC ducting
- Bus duct and building structural steel (pay particular attention to cross-bracing).
- Cable tray and building structural steel (pay particular attention to cross-bracing).
- Conduit stub ups and building structural steel and cross bracing.
- Conduit stub ups and floor system structural components for pre-manufactured buildings.
D1.14 Allow sufficient clearances and dedicated working space as required by NEC Articles 110.26 through 110.40. Check location of building cross bracing for equipment installation clearances. Refer to 4EL64552A for additional details.
D1.15 EMT conduit in buildings with a finished inside wall (e.g., offices, control room) should be shown inside the walls.
Note: The electrical contractor must coordinate with the building contractor regarding installing conduit in walls.
D1.16 Short circuit terminal blocks in all terminal boxes for remote current transformer circuits. CT wiring shall be identified and color coded wherever visible. Refer to 4AEL-620300 for color coding requirements.
D1.17 Wall-mounted 120 volt duplex receptacles shall be provided in laboratories as follows:
Quantity of two in combined analyzer/laboratory room, combined analyzer/laboratory room or a separate laboratory building.
Quantity of one in water treatment building laboratory.
All receptacles to be located just above the laboratory furniture work top.
- All laboratory receptacles shall be protected by ground fault circuit interrupting breakers.
D1.18 Equipment grounding shall be provided for all freestanding metallic structures, including cold boxes, miscellaneous boxes, and heat exchangers. All free standing instrument racks need to be grounded to the ground grid. Refer to 4EL64352A and 4EL64353A for additional details.
D1.19 Plant alarm horns shall be located for suitable sound levels in all areas of the plant according to the machinery engineer’s recommendations.
D1.20 Green lights at each door to light when exhaust fans are operating in buildings where asphyxiation or combustion hazards exist. Refer to 3ES80101 for additional details.
D1.21 Pull boxes for 600 volt power wiring (#4 AWG and larger) and all medium voltage cable shall be adequately sized according to NEC tables.
D1.22 Cable tray rung spacing shall not exceed 225 mm (9 in) when #1/0 AWG through #4/0 AWG single conductor cables are used. #1/0 AWG is the smallest single conductor cable allowed in cable tray. When single conductor cables are installed in cable tray the smallest allowable ground wire size is #4 AWG.
Appendix D (continued)
Physicals Checklist
D1.23 Cable tray supports at elbows, tees, crosses, risers, etc., per NEMA VE-1 guidelines. Refer to STD-P331A (four sheets) for additional information.
D1.24 Building steel columns to be grounded at every other column.
D1.25 Equipment grounding conductors sized according to NEC 250-122 for each parallel grounding conductor with parallel feeders.
D1.26 Note indicating it is the contractor’s responsibility to pour conduit seals on supplier-provided skids (with approximate quantities) for hazardous area skids.
D1.27 In Class I, Group B, areas, conduit seals must be approved for use in Group B installations. Reference 620.301 on drawings.
D1.28 Digital input wiring, where run in close proximity to 480 volt AC wiring (in motor control centers, control panels, etc.) shall have 600V insulation.
D1.29 Redundant DCS communication cables (data highway, fiber optic, etc.) shall have different paths and be separated for reliability whenever feasible and practical.
D1.30 Control room lighting shall consist of two lighting circuits. One circuit to be dedicated to lights in the immediate HMI vicinity to allow turning down lighting for better viewing of HMI displays. Dimmer switches and special fluorescent lights might be required.
D1.31 For an elevated reactivation heater (08.23), locate the temperature controller at grade near the on/off hand switch. Locate the flow switch on the platform visible from the associated valves.
D1.32 For large outdoor centrifugal compressors, locate stanchion-mounted lighting fixtures along the handrail directly opposite the gearbox such that compressor convolutes don’t cast shadows.
D1.33 Convenience GFCI receptacle for MCC pit sump pump should be located in the bottom wiring trough of the MCC, directly above the sump location.
D1.34 Convenient receptacle for the E2 motor starter test power source should be located within 25 feet of the starter line-up. A separate receptacle is not necessary when test power source is an integral part of E2 starter.
D1.35 Deoxo system must be classified Class I, Division 2, Group B, within 15 feet sphere of hydrogen supply and crude argon blending station and all other point sources of hydrogen. In addition, conduits to instruments in the recycle gas line from the top of the pure argon column must be sealed.
D1.36 Verify if motor terminal boxes supplied with manufacturer’s equipment (non-Air Products specified motor terminal boxes) have sufficient capacity to accommodate motor leads, field cables, and Air Products required lugs. If box is too small, notify equipment specifier to have supplier provide box size required or identify replacement box to be provided by field contractor.
D1.37 Verify space between floor and current transformers (CTs) in switchgear and starter cabinets provides sufficient room to extend field cables through CTs without exceeding maximum bending ratio of the cables.
D1.38 Provide DCS cabinet elevation layout (of all accessible sides) or include DCS supplier documentation with construction drawings
D1.39 Provide conduit fill charts and homerun wiring details and notes when applicable.
Appendix D (continued)
Physicals Checklist
D1.40 When design includes provisions for power to liquid tank trucks and trailers, verify power requirements with the GG&S Organization. In cold weather locations trucks are provided with engine block heaters. Parking areas for these trucks are generally supplied with stanchion-mounted GFCI receptacles to plug in heater cords from trucks.
D1.41 Identify use aluminum conduit and fittings around Cooling Tower Area on drawings.
D1.42 Uninterruptible power supply (UPS) and regulated power shall be run in separate conduits from normal power or in shielded cable in cable trays when run with normal power.
D1.43 Verify general drawing notes reference 4AEL-620300.
D1.44 Ensure the physical arrangement of switchgear, E2 starters, and motor control centers accurately depict cubicle arrangements shown on supplier print layout of equipment and match layout and numbering on Single Line Diagrams. Confirm that equipment fronts are properly oriented in relation to other equipment in room. Identify “Front” of each unit on drawing.
D1.45 Compare above ground physical drawings versus underground conduit and grounding drawings to verify conduit stub-ups and grounding pigtails are shown and accurately located. Verify drawings note contractors responsibility for extending conduit stub-ups to equipment and connection of grounding pigtails to equipment. Reference standard installation drawings as required.
D1.46 All electrical buildings require smoke detectors wired to DCS for alarm.
D1.47 All motor space heaters or other >48V motor auxiliary equipment require local lockout disconnect switches.
D1.48 All convenience receptacles located in lavatories, kitchens, maintenance areas, Electrical buildings and outdoors shall have GFCI protection.
D2. Canadian Electrical Code Requirements
D2.1 Line-of-sight disconnect switches within 9 m (29.5 ft) of each motor unless special permission is granted to use out-of-sight, lockable, open-type disconnects.
D2.2 Receptacles rated for overcurrent protection setting (e.g., 15A receptacle not acceptable if fed from 20A breaker).
D2.3 Wiring for lighting and receptacles must be run in separate conduits from power and control wiring.
D2.4 1.1 m (3 ft 6 in) between the fence and enclosures containing live parts (e.g., transformers).
D3. California Code Requirements (Medium Voltage)
D3.1 Rigid metal conduit shall be specified for 2300 VAC and above.
D3.2 Schedule 80, polyvinyl chloride (PVC), conduit may be used underground for shielded cable. Nonshielded cable requires rigid metal conduit.
D3.3 Manholes to be at least 6.5 ft from floor to ceiling. Manhole access clearance shall be at least 24 x 26 inches.
Appendix E
Wiring Diagram and Conduit/Cable Schedule Checklist
E1. Multiconductor control/power cable shall have a minimum of 25% spare conductors. Spare conductors shall be shown grounded at both ends to minimize the induced voltages between conductors.
E2. Multiconductor control/power cable in PVC conduit shall include a ground wire. To distinguish ground wire from grounded spares, the ground wire shall be taped with green tape or stripped of insulation wherever cable is exposed.
E3. Multiconductor instrument and thermocouple cable shall have an overall cable shield grounded at one point only. Generally the DCS equipment (safety) ground bus or the control panel safety ground bus.
E4. All metal control terminal boxes, pull boxes, and wireways (fed from the PVC underground conduit) shall be grounded with a ground wire. Nonmetallic boxes shall have a ground bus installed in the box that shall be supplied with a grounding conductor. Refer to 4EL64127A for additional details.
E5. Conductors associated with emergency systems (e.g., fire pumps, emergency lighting) are not permitted to be installed in the same raceway as normal plant wiring.
E6. Power shall be supplied to all electrically traced tube bundles. Verify location and quantity of heat‑traced tubing bundles with Instrument Design.
E7. Polarity markings on terminal strips for instrumentation wiring within control panels.
E8. Confirm thermocouple single and multi-cable element matching versus instrument specifications.
E9. Thermocouples grounded at element and float at DCS or controller end (for grounded thermocouples).
E10. Verify general drawing notes reference 4AEL-620302.
E11. On Conduit and Cable schedules check cross-references between field equipment and electrical distribution equipment (switchgear, starters, and motor control centers) and programmable control cabinets (e.g., DCS, PLCs) to confirm “TO” or “FROM” equipment identification (e.g., MCC Comp. 7AF) matches actual equipment termination location.
E12. Current transformer (CT) wiring shall be run to relays direct and with no splices in wiring if possible. Any required splices shall be made in terminal boxes, adequately identified and must be made with short circuit terminal blocks. Terminating CT wiring on standard terminal blocks is not permitted.
E13. DC motor stator field wiring shall not be spliced.
Appendix F
Underground Checklist
F1. General Underground Systems
F1.1 Conduit bend limitations should not exceed 300 degrees for cable or 285 degrees for tube bundles. Manual calculation or a cable pulling program should be used for verification of pulling tensions and sidewall tensions for long conduit runs or runs with multiple bends.
F1.2 Verify standard drawing notes are used to identify the following:
- Type of conduit to be installed.
- Minimum burial depth of conduits. (Conduits must be buried below facility frost line. Adjust burial depth accordingly.)
- Identify which conduits require concrete encasement.
Note: All conduits containing medium voltage cable must be concrete encased.
- Identify which conduits require large radius bend elbows and minimum radius required.
F1.3 Verify conduits installed under roadways, parking areas, and other areas of heavy vehicular traffic are identified for concrete encasement.
F1.4 Verify conduits sleeves are installed under roadways, parking areas, and other inaccessible areas to facilitate installation and future removal of direct buried roadway lighting cables.
F1.5 Identify conduit installation potential interferences, both existing and new.
F1.6 Conduit banks should slope away from the MCC pit and slope toward manholes. Manholes should be provided with sump openings in bottom to allow for pump-out by portable pump.
F1.7 PVC conduit duct-to-duct centerline spacing is 5.5 inch for 3-inch conduit and less, or 7.56 inch for 3 1/2 inch to 5 inch conduit to correspond to spacers.
F1.8 Reference specific details from drawing STD-P315A for conduit stub-ups.
F1.9 Test wells must be provided as part of the facility grounding electrode system. Generally one test well at the Electrical Building and one test well at the Control Building is sufficient.
F1.10 Underground conduit to the scale house and the remote PCU room for telephone service, unless access is available to location from overhead.
F1.11 Verify sufficient spare conduits are provided for future facility growth.
F1.12 Provide foundation heat-tracing conduits for site erected tanks, cold boxes, and column cans. Refer to 4EL64401A for additional details.
F1.13 Review 4EL64352A and 4EL64353A for facility grounding design compliance.
F1.14 Grounding electrode conductors shall be minimum #2/0 AWG.
F1.15 Verify reference on drawings to foundation reinforcing grounding (Ufer) drawing STD-G313A.
Appendix F (continued)
Underground Checklist
F1.16 Grounding electrode system must be buried a minimum of 30 inches below grade as required by the NEC.
F1.17 All grounding pigtails and segments of the grounding system are connected together to form the facility grounding electrode system.
F1.18 Verify grounding electrode pigtails are provided for transformer neutral grounding bushing connections (medium and low voltage), neutral grounding resistor, each DCS remote cabinet, all free standing instrument racks, cable tray supports (independent of pipe rack supported cable tray), lightning protection system down conductors, all separately derived systems. Refer to 4EL64352A and 4EL64353A for additional details.
F1.19 Verify pigtails provided for grounding every other building column and pipe rack steel every 50 ft maximum.
F2. Interconnected Grounding Electrode Systems
F2.1 When facility power is supplied from a utility company substation or customer substation, verify two connections identified between Air Products facility and substation grounding electrode system.
F2.2 When facility power is supplied by customer feeder, verify at least one connection is identified between Air Products facility and customer’s grounding electrode system. If customer’s grounding electrode is not available, verify grounding conductor is provided with customer feeder.
F2.3 When adding new equipment in an existing facility, verify two connections identified between new grounding electrode system and existing facilities grounding electrode system.
F2.4 Review the following utility services entering a facility from outside the battery limits. These services must be properly grounded to the facility grounding system as required by code:
- Incoming public telephone
- Inter-plant communication systems
- DCS system I/O bus and M-Net cables
- Ethernet systems