* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Risk Assessment Lab Electrical Electrical Engineering Lab Example 1
War of the currents wikipedia , lookup
Electronic engineering wikipedia , lookup
Opto-isolator wikipedia , lookup
Electrification wikipedia , lookup
Fault tolerance wikipedia , lookup
Buck converter wikipedia , lookup
Electrical engineering wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Ground loop (electricity) wikipedia , lookup
Public address system wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Electrician wikipedia , lookup
Power engineering wikipedia , lookup
Surge protector wikipedia , lookup
Mercury-arc valve wikipedia , lookup
Rectiverter wikipedia , lookup
Stray voltage wikipedia , lookup
Voltage optimisation wikipedia , lookup
History of electric power transmission wikipedia , lookup
Electrical substation wikipedia , lookup
Electromagnetic compatibility wikipedia , lookup
Ground (electricity) wikipedia , lookup
Circuit breaker wikipedia , lookup
Alternating current wikipedia , lookup
Telecommunications engineering wikipedia , lookup
Portable appliance testing wikipedia , lookup
National Electrical Code wikipedia , lookup
Electrical wiring in the United Kingdom wikipedia , lookup
Laboratory Standard Operating Procedure – Electrical Apparatus Used or Fabricated in Laboratory/Research Areas – Risk Assessment The Pennsylvania State University Office of Environmental Health and Safety 6 Eisenhower Parking Deck University Park, PA 16802 Please fill out the form and then print it on your local printer and place in your Laboratory and Research Safety Plan. Date 7/12/16 Location: Penn State Engineering Lab Principal Investigator Dr. John Doe, Professor of Electrical Engineering Room and Building 11106 - Building 101 Phone Number 123-456-3300 A short description was added to this risk assessment: The Electric Machines laboratory is used for faculty and undergraduate student research in the area of power electronics, electric machines, and electric drives. The laboratory is equipped with a variety of regulated DC power supplies, 3 phase inverters, dSpace rapid prototyping tools, electric motors, and a small dynamometer. Research projects have included development, implementation, and testing of various inverters for motor drives (resonant pole, GaN based drive, sensorless control of PMSM, etc.). The nature of the research often involves working with live electric circuits (inverters) operating at DC bus voltages of less than 50V. (Check to Acknowledge) Section 1: X Electrical task involves electrical apparatus used or fabricated in laboratory/research areas. -Does not include common electrical devices used as originally intended by the manufacturer. Such items include but aren’t limited to those bought at any department store, appliances, hot plates, power strips, wood/metal wooding machines, refrigerators, microwaves, ovens, etc. Section 2: Determine if interaction with live parts is necessary. NOTE: In a lab environment live work is only permitted when: Page 1 of 10 Deenergizing is not possible due to equipment design or operational limitations. Examples of this situation would include diagnostic work such as voltage measurements, troubleshooting, and testing of electrical equipment. Live parts are operating at less than 50 volts and there is no increased exposure to electrical burns or to explosion due to electrical arcs. Will there be interaction with live parts?:Yes live up to 42 volts however have an additional variable power supply that is capable of supplying 150 volts. Currently, use equipment that has the capability to use 42 volts No. Equipment will be disconnected from power source (i.e Lockout Tagout). If answered NO, the rest of this document can be left blank. Equipment can be unplugged and also has an on/off switch. X Yes, explain the tasks where the person/s are required to interact with live parts: NOTE: Be aware of power source and capabilities. (i.e. low voltage, high power devices, switch testing, capacitors) Diagnostic testing required while powered. Supplies are purchased however the inverter and/or motor drive is fabricated. Section 3: If equipment is “used” (not purchased new from the manufacturer), determine if there are any known issues/problems with the equipment: No known issues/problems X Yes: Has issues/problems. If Yes, Explain issue/problems and corrective actions to fix: Potential use issues/problems: Experimental by nature, power electronic circuit may not be wired correctly, etc. Controls: perform proper visual inspections before each use, ensure design incorporates proper circuit protection into power supply or experiment, add controls such as fuses, etc. Section 4: Perform a visual inspection of the equipment to look for damage: X No damage Yes: Has damage. If Yes, Explain damage and corrective actions to fix: Page 2 of 10 Section 5: Perform a visual inspection of the equipment to ensure it is properly grounded to prevent shock. Not properly grounded. Explain what will X - Yes: properly grounded. be done to ensure proper grounding of Check all that apply: equipment: X - Equipped with a 3-prong plug A portable GFCI outlet is used Equipment is connected to a wall outlet that is a GFCI X Equipment is connected to a circuit breaker that is designed to operate as a GFCI Equipment is hard wired into a building electrical panel that has a proper ground established. Verified by OPP electrician/or electrician. Section 6: Determine if additional safety devices/equipment can be installed on/with the equipment to reduce hazard (i.e. DC Isolation Monitors). Ensure power supply grounded. None required/Not Applicable X Yes: If yes, explain what additional devices will be utilized: Ideal work environment – nonconductive work surface, clean work environment, adequate electrical power supply, good housekeeping, use of rated and proper electrical equipment. etc. Section 7: Distinguish live parts from other parts of equipment: Not necessary: All live parts are enclosed during normal operation. X Live parts may be exposed during normal operation. How will these parts be distinguished (color, notes, labels, signs, etc): Nothing physical, not operating unattended, access control, SOP, training, low voltage Section 8: Determine how to insulate/guard/enclose/limit access to energized electrical conductors/circuits/parts 50 volts or higher in the system to reduce/eliminate exposure during normal operation: X Not Necessary: Less than 50 volts Necessary. Explain: o NOTE: Only non-conductive devices can be used. . If higher than 50 volts normal operation would be exposed for trouble shooting, Need to reference PPE for electrical safety program Page 3 of 10 Section 9: Determine the highest nominal system voltage: X What is the nominal voltage? Variable power supply equipment in lab has the ability to use 150 volts but lab does not have the equipment to utilize it currently. Proper PPE will be assessed and used if working with equipment greater than 50 volts. Section 10: Determine minimum approach distances to exposed live parts for shock protection (utilizing Appendix B: Approach Boundaries to Energized Electrical Conductors or Circuit Parts for Shock Protection seen below as retrieved from the PSU Energized Electrical Safety Program) : Appendix B Approach Boundaries to Energized Electrical Conductors or Circuit Parts for Shock Protection (All dimensions are distance from fixed live part to employee) Alternating Current (AC) Nominal System Voltage Limited Restricted Approach Approach Boundary Boundary Less than 50 V Not Specified Not Specified 50 V to 150 V 3 feet, 6 inches Avoid Contact 151 V to 750 V 3 feet, 6 inches 1 foot 751 V to 15 kV 5 feet 2 feet, 2 inches Over 15 kV or a movable conductor (a condition in which the distance between the conductor and a person is not under the control of the person) See NFPA 70 E Table 130.4 (D)(a) Direct Current (DC) Nominal Potential Limited Approach Restricted Approach Boundary Difference Boundary < 100 V Not Specified Not Specified 100 V to 300 V 3 feet, 6 inches Avoid Contact 301 V to 1 kV 3 feet, 6 inches 1 foot Over 1 kV or a movable conductor (a condition in which the distance between the conductor and a person is not under the control of the person) See NFPA 70 E Table 130.4 (D)(b) Definitions Limited Approach Boundary is an approach limit at a distance from an exposed live part within which a shock hazard exists. Restricted Approach Boundary is a distance from an exposed energized electrical conductor or circuit part within which there is an increased likelihood of electric shock, due to electrical arc-over combined with inadvertent movement, for personnel working in close proximity to the energized electrical conductor or circuit part. List the distances: Page 4 of 10 Limited Approach Boundary :3 feet six inches Restricted Approach Boundary :Avoid Contact Section 11: Determine the appropriate PPE for each task: If equipment is hard wired into the facility/building electrical system utilize Appendices below. -Appendix C: Arc flash Hazard Identification -Appendix D: Arc flash hazard PPE categories for Alternating Current (AC) Equipment & Direct Current (DC) Equipment -Appendix E: Personal Protective Equipment X If equipment is cord and plug connected perform a PPE hazard assessment based on the manufactures recommendations, equipment design and voltage. Use Appendices C-E below for guidance. Note that arc flash PPE and/or shock protection PPE may be necessary. Appendix C Arc flash Hazard Identification – Alternating Current Equipment (AC) and Direct Current Equipment (DC) Task Equipment Condition Reading a panel meter Any while operating a meter switch All of the following: Normal The equipment is properly installed operation The equipment is properly maintained of a circuit All equipment doors are closed and secured breaker All equipment covers are in place and secured (CB), There is no evidence of impending failure Note: All of the following requirements must be met to satisfy the “no arc flash PPE switch, contactor, required” scenario: 1) Covers/panels that enclose the circuit breaker (CB), switch, contactor, or starter are in place, or starter and secure. 2) 3) 4) 5) 6) 7) 8) 9) No visual damage to the enclosure of the circuit breaker (CB), switch, contactor, or starter. No visual damage to the circuit breaker (CB) switch, switch, contactor, or starter. No visual damage to the wires/conduits at entry/exit points to the enclosure. No knockouts missing. No evidence of water/liquid damage (puddling, rust, chemicals). No evidence of heat/fire damage (discoloration). No bolts, screws, fasteners missing. No exposed live parts of the enclosure (proper blanks used to cover empty circuit breaker locations) If conditions in 1-9 are found to be satisfactory, a circuit breaker (CB), switch, contactor, or starter can be used to turn off/on a circuit without PPE. Page 5 of 10 Arc Flash PPE Required No No *********Resetting a tripped breaker********* If conditions in 1-9 are found to be satisfactory and circuit breaker operation training has been completed, a tripped circuit breaker can be reset without PPE ONLY IF after investigation reveals a probable cause of the trip (overloaded circuit). ADDITIONALLY, the circuit breaker is only permitted to be reset only 1 time. A person who has been qualified to troubleshoot an electrical circuit (i.e. electrician) must be notified if the breaker trips a 2nd time. Normal operation of a circuit breaker (CB), switch, contactor, or starter One or more of the following: The equipment is not properly installed The equipment is not properly maintained Equipment doors are open or not secure Equipment covers are off or not secured There is evidence of impending failure Yes Appendix C Arc flash Hazard Identification – Alternating Current Equipment (AC) and Direct Current Equipment (DC) Task Equipment Condition For ac systems: Work on energized electrical conductors and circuit parts, including voltage testing For dc systems: Work on energized electrical conductors and circuit parts of series-connected battery cells, including voltage testing Voltage testing on individual battery cells or individual multi-cell units Any Arc Flash PPE Required Yes Any Yes Removal of bolted covers (to expose bare energized electrical conductors and circuit parts). For dc systems, this includes bolted covers, such as battery terminal covers Removal of battery intercell connector covers Page 6 of 10 All of the following: The equipment is properly installed The equipment is properly maintained Covers for all other equipment are in place and secured There is no evidence of impending failure One or more of the following: The equipment is not properly installed The equipment is not properly maintained Equipment doors are open or not secure Equipment covers are off or not secured There is evidence of impending failure Any All of the following: The equipment is properly installed The equipment is properly maintained Covers for all other equipment are in place and secured There is no evidence of impending failure One or more of the following: The equipment is not properly installed The equipment is not properly maintained Equipment doors are open or not secure Equipment covers are off or not secured There is evidence of impending failure No Yes Yes No Yes Appendix C Arc flash Hazard Identification – Alternating Current Equipment (AC) and Direct Current Equipment (DC) Arc Flash Task Equipment Condition PPE Required Opening hinged door(s) or cover(s) (to expose bare energized Any Yes electrical conductors and circuit parts) Work on control circuits with exposed energized electrical Any No conductors and circuit parts, 120 volts or below without any exposed energized equipment over 120 V including opening of hinged covers to gain access Work on control circuits with exposed energized electrical Any Yes conductors and circuit parts, greater than 120 V Insulated cable examination with no manipulation of cable Any No Insulated cable examination with manipulation of cable Any Yes Work on exposed energized electrical conductors and circuit Any Yes parts of equipment directly supplied by a panelboard or motor control center For dc systems, insertion or removal of individual cells or Any Yes multi-cell units of a battery system in an enclosure For dc systems, insertion or removal of individual cells or Any No multi-cell units of a battery system in an open rack For dc systems, maintenance on a single cell of a battery Any No system or multi-cell units in an open rack For dc systems, work on exposed energized electrical Any Yes conductors and circuit parts of utilization equipment directly supplied by a dc source Additional Information: Hazard Identification is one component of risk assessment. Rick assessment involves a determination of the likelihood of occurrence of an incident, resulting from a hazard that could cause injury or damage to health. The assessment of the likelihood of occurrence contained in the table does not cover every possible condition or situation. Where this table indicates that arc flash PPE is not required, an arc flash is not likely to occur. The phrase “properly installed”, as used in this table, means that the equipment is installed in accordance with applicable industry codes and standards and the manufacturer’s recommendations. The phrase “properly maintained”, as used in this table, means that the equipment has been maintained in accordance with manufacturer’s recommendations and applicable industry codes and standards. The phrase “evidence of impending failure”, as used in this table , means that there is evidence of arcing, overheating, loose or bound equipment parts, visible damage, deterioration, or other damage. Page 7 of 10 Appendix D Arc flash hazard PPE categories Alternating Current (AC) Equipment Equipment Panelboards or other equipment rated 240 V and below Parameters: Maximum of 25 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time; working distance 18 in. Panelboards or other equipment rated greater than 240 V and up to 600 V Parameters: Maximum of 25 kA short circuit current available; maximum of 0.03 sec (2 cycle) fault clearing time; working distance 18 in. Other 600 V class equipment (277 V through 600 V nominal) Parameters: Maximum of 65 kA short circuit available; maximum of 0.03 sec (2 cycle) fault clearing time; working distance 18 in. Arc Flash PPE Category 1 2 2 Arc Flash Boundary For AC systems that are 600 volts or less, the arc flash boundary shall be a minimum of 20 feet or the entire room if a boundary of 20 feet cannot be obtained (i.e. room is smaller than 20 feet). If the equipment has an NFPA 70E label attached its stated arc flash boundary should be used. Direct Current (DC) Equipment Equipment Arc Flash Arc-Flash PPE Boundary Category Storage batteries, dc switchboards, and other dc supply sources 100V or greater less but less than 250V. Parameters: Voltage: 250 V Maximum arc duration and working distance: 2 sec @ 18 in. Short-circuit current less than 4 kA 1 3 feet Greater than 4 kA short-circuit current but less than 7 kA 2 4 feet Greater than 7 kA short-circuit current but less than 15 kA 3 6 feet Storage batteries, dc switchboards, and other dc supply sources 250 V or greater but less than 600V. Parameters: Voltage: 600 V Maximum arc duration and working distance: 2 sec @ 18 in. Short-circuit current less than 1.5 kA 1 3 feet Greater than 1.5 kA short-circuit current but less than 3 kA 2 4 feet Greater than 3 kA short-circuit current but less than 7 kA 3 6 feet Greater than 7 kA short-circuit current but less than 10 kA 4 8 feet Additional Information: “Short-circuit current” as used in this table, is determined from the dc power system maximum available shortcircuit, including the effects of cables and any other impedances in the circuit. Power system modeling is the best method to determine the available short-circuit current at the point of the arc. Battery cell short-circuit current can be obtained from the battery manufacturer. The methods for estimating the dc arc flash incident energy that were used to determine the categories for this table are based on open-air incident energy calculations. Open-air calculations were used because many battery systems and other dc process systems are in open areas or rooms. If the specific task is within an enclosure, it would be prudent to consider additional PPE protection beyond the value shown in this table. Research with ac arc flash has shown a multiplier of as much as 3x for arc-in-a-box versus open air. Page 8 of 10 PPE Category 1 2 Appendix E: Personal Protective Equipment PPE Arc Rated Clothing, Minimum Arc Rating of 4 cal/cm2 Arc-rated long-sleeve shirt and pants or Arc- rated coveralls Arc-rated face shield (see Note 2) or arc flash suit hood Arc-rated jacket, parka, rainwear or hard hat liner (AN) Protective Equipment Hard hat Safety glasses or safety goggles Hearing protection (ear canal inserts) Heavy duty leather gloves with rubber insulating gloves (see note 1) Leather footwear (AN) Arc Rated Clothing, Minimum Arc Rating of 8 cal/cm2 Arc-rated long-sleeve shirt and pants or arc-rated coveralls Arc-rated flash suit hood or arc-rated face shield (note 2) AND arc-rated balaclava Arc-rated jacket, parka, rainwear, or hard hat liner (AN) Protective Equipment Hard hat Safety glasses or safety goggles Hearing protection (ear canal inserts) Heavy duty leather gloves with rubber insulating gloves (see note 1) Leather footwear AN: As Needed AR: As Required Notes: 1. 2. If rubber insulating gloves with leather protectors are used, additional leather or arc-rated gloves are not required. The combination of rubber insulating gloves with leather protectors satisfies the arc flash protection requirement. Face shields are to have wrap-around guarding to protect not only the face but also the forehead, ears, and neck, or, alternatively, an arc-rated arc flash suit hood is required to be worn. Check all PPE required for the task utilizing <50 volts DC: X Safety Glasses Arc Flash Face Shield X Leather Gloves Arc Flash Balaclava Voltage Rated Rubber Gloves (NOTE: gloves are required to be sent to a 3rd party every 6 months to ensure they are still in a nonconductive state. Alternatively a new pair of gloves can be purchased every 6 months and the old pair discarded.) Arc Flash Clothing Section 12: Determine the proper insulated tools needed: No insulated tools are required because no work on live parts will be done. X Yes, live work may be necessary, such as testing/troubleshooting, the following tools are required to be insulated (pliers, sockets, strippers, crimpers, wrenches, etc): List the tools below: Pliers Strippers Screw driver Crimpers Page 9 of 10 Section 13: Determine the appropriate voltage rated test instruments to utilize: No test instruments are required X Yes, test instruments are required: List the test instruments below: Voltage meter Section 14: Determine and identify appropriate emergency shutdown/shutoff procedures: Explain: SOP – Unplug Equipment Section 15: Determine the appropriate energy isolation procedures to use in order to perform servicing/maintenance on the equipment (i.e. Lockout/Tagout (LOTO) procedures): X Cord and plug powered. Unplug cord and ensure unauthorized persons do not re-energize (cord to be kept under the continuous control of the person performing the servicing/maintenance) Hard-wired via circuit breaker/disconnect lever Step 1 – ID energy source Step 2 – Notify Others Step 3 – Shutdown equipment (how it is typically shutdown) Step 4 – Isolate equipment (open circuit breaker/disconnect) Step 5 – LOTO equipment (attach lock and tag to circuit breaker/disconnect) Step 6 – Release stored energy Step 7 – Verify Isolation (try to start equipment and/or test for voltage) Step 8 – Perform servicing/maintenance Step 9 – Release form LOTO Section 16: Describe Procedure/Task/Process. (NOTE: attaching the task specific procedure/process/instructions/SOP to this form is permitted): See Laboratory and Safety Research Plan and Unit Specific Plan Page 10 of 10