1 +1-847-367-4077 Guide to Electrical Safety Testing Safety Is Our Only Focus®
1 +1-847-367-4077 Guide to Electrical Safety Testing Safety Is Our Only Focus® 3 +1-847-367-4077 arisafety.com 2 GENERAL INFORMATION GENERAL INFORMATION Why Test? There are four main reasons why you should safety test your products prior to shipment 1. Safety Ensure that the product is not going to pose a hazard to the end user. 2. Quality Detect workmanship defects and prevent faulty components from being installed. 3. Cost Control Identify production problems before a product is shipped, preventing costly recalls. 4. Liability Prevent product liability suits because the responsibility of performing electrical safety tests ultimately rests on the manufacturer NRTL standards dictate that electrical products incorporate two lines of defense to protect the user from electrical shock Insulation Safety Grounds • Separates power lines from low voltage circuits. • Separates power lines from isolated power supplies. • Isolates input power from the chassis or case of an electrical device. • Allow dangerous fault currents to return to system ground. • Enables circuit breakers to open. • Safeguards against fire. • Protects against damage to electrical equipment. Effects of the electrical current on the human body Current Reaction** 0.5 to 1 milliamp Perception 5 milliamps Slight shock felt, startled reaction 6 to 30 milliamps Painful shock and inability to let go 30 to 150 milliamps Extremely painful, respiratory arrest, ventricular fibrillation, death possible 10 amps Cardiac arrest, severe burns ** These effects are for voltages less than 600 volts. Many electrical safety instruments can output voltages in excess of 5000 volts which can cause more severe reactions at lower current levels. NRTLs (Nationally Recognized Testing Laboratories) set standards outlining tests that must be performed on a product before it’s considered safe for the consumer market. NRTLs implement and enforce electrical safety testing to protect consumers from a potentially fatal electric shock. As a manufacturer or test operator, it’s up to you to ensure you have the proper knowledge and training to use high voltage equipment. Before working with an electrical safety test station, you need to make sure you are a qualified operator according to OSHA guidelines 1. NRTL Examples: Underwriters Laboratories (UL - United States), TUV Rheinland (Germany), Canadian Standards Association (CSA - Canada), ETL (Intertek - United States) and CCC (China Compulsory Certification - China) Electrical products can be classified according to insulation type Class I Products • Terminate in 3 prong line cord (line, neutral and ground). • Ground prong connects to product chassis. • Safety through basic insulation and proper grounding. Class II Products • Double insulated products. • Terminate in 2 prong line cord (line and neutral). • Safety through dual layer of insulation. NRTL standards generally specify two separate testing categories Type Test • Performed as a laboratory or prototype test • Done on sample basis • Used to detect defects in product design • More rigorous testing Production Line Test • Performed on 100% of products on the production line. • Used to detect manufacturing or workmanship defects 1OSHA 29 CFR part 1910.332 Subpart S defines the training requirements for anyone exposed to voltages in excess of 50 volts. Occupational Safety and Health Administration An agency of the United States Department of Labor charged with ensuring safe working conditions as well as enforcing standards and providing workplace training and education. OSHA 1910.332 Subpart S • osha.gov 5 +1-847-367-4077 arisafety.com 4 OPERATOR SAFETY AND TRAINING OPERATOR SAFETY AND TRAINING A Qualified Operator Must Know A Qualified Operator Must Know Knowledge Example 1. Determine whether an exposed conductor is energized or not. Hipot instrument with the output voltage ON. HIGH VOLTAGE warning symbol illuminate RED when the instrument is outputting. This indicates that the instrument is in a dangerous state. 2. Determine the nominal voltage of an electrical circuit by reading drawings, signs and labels. Know how to use the equipment. Every instrument should come with a user’s manual. Review this manual prior to using the equipment. Product power cord with label displaying the nominal voltage and current of the device. 3. Understand approach distances and corresponding voltages to which you may be exposed.2 Associated Research instruments can output up to 5000 VAC. Always review product specifications before using the equipment. 4. You should be trained to identify and understand the relationship between electrical hazards and possible injury. Refer to the table “Effects of Current on the Human Body” on the preceding page. 5. Know the safety features of the equipment and utilize them. Most Associated Research instruments have an automatic discharge circuit that will discharge the DUT in less than 200 msec after the test completes. This ensures the DUT is safe for you to touch once the test has completed. Smart GFI & Interlock 6. Determine if Personal Protective Equipment (PPE) is necessary, what type of PPE3 is necessary and how the PPE is rated. OSHA now requires in addition to being a Qualified Person, that you must wear PPE for protection from shock if you cross the Restricted Boundary. Note: The restricted boundary for live parts operating between 751 V and 15 kV is 2 feet x 2 inches. This image contains high voltage gloves, safety glasses, a hard hat and high voltage boots. These are common examples of the PPE you should wear as an operator when using high voltage equipment. Knowledge Example 7. Know the methods of release for victims who are being shocked. Methods include using a non-conductive material (i.e. a fiberglass pole) to release someone from a live circuit. Using an E-Stop can also shut off power to the entire station and release the victim. DO NOT touch a person who is being shocked or you could also become part of the circuit! 8. Understand that the instrument is a variable voltage power source that will output current to any available ground path. Contacting the DUT during the test can result in a dangerous shock hazard. This image shows someone contacting a live circuit. The current flows directly through their body to ground causing severe, possibly fatal injuries. 9. You must know the importance of discharging the DUT. While all Associated Research instruments do have an automatic discharging circuit, lifting the high voltage or return lead from the DUT before the test is complete can leave the DUT charged. If the Hipot does not have a complete circuit, it cannot discharge the DUT at the end of the test. 10. Understand that each step in the work plan must be executed as planned. DO NOT TAKE SHORT CUTS! Refer to Test Station Safety Procedure Checklist (page 15) to review your Hipot setup before you test. 2 NFPA 70E Table 130.2(C) outlines approach boundaries to live parts for shock protection. 3 NFPA 70E Section 130.7(C)(10) shall be used to determine the required PPE for the task. 7 +1-847-367-4077 arisafety.com 6 OPERATOR SAFETY AND TRAINING OPERATOR SAFETY AND TRAINING Setting up a Safe Workstation One of the best ways to prevent injury is to ensure that the test station is set up safely and securely. Test stations can be setup with or without direct protection depending on your requirements. Direct protection means that the operator cannot physically come into contact with an energized DUT while a test is running. 10' 10' A E G H C F D B J I 10' 10' DANGER HIGH VOLTAGE AUTHORIZED PERSONNEL ONLY E-STOP A E E G G H C F F D B E-STOP 4 High Voltage signs compliant to ANSI Z535-2011 5 See NFPA 70E Table 130.2(C) Reference Description A DUT – This large DUT prevents you from using a product safety enclosure. Instead, other precautions must be taken to ensure a safe testing station. B The Hipot Instrument – instrument used to test the DUT. C Test Operator. D High Voltage Insulation Mat – This isolates you from ground which provides an additional means of protection when operating high voltage equipment. E Signal Tower Light – gives an indication as to the status of the testing area. A green light indicates the Hipot instrument is not outputting high voltage and the test area is safe. A red light indicates that the Hipot instrument is active and to stay clear of the test area. F Emergency Stop Button – An E-stop button is located on the perimeter of the test area. In the event of an emergency, someone outside the test area can hit the E-Stop button to immediately cut off power to the entire test station. G Warning Signs4 – Mark the testing area with clearly posted signs that read: DANGER-HIGH VOLTAGE TEST IN PROGRESS. UNAUTHORIZED PERSONNEL KEEP AWAY. H Sectioned Off Test Area – Since the size of the DUT restricts the use of an enclosure, this test area is sectioned off by a mesh fence to keep unauthorized personnel away from the testing station. NEC (National Electric Code) and NFPA (National Fire Protection Agency)5 stipulate that any unqualified workers shall not come within 10 feet of uploads/Voyage/ guide-to-electrical-safety-testing-safety-is-our-only-focus.pdf
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Licence et utilisation
Gratuit pour un usage personnel Attribution requise- Détails
- Publié le Apv 01, 2022
- Catégorie Travel / Voayage
- Langue French
- Taille du fichier 4.3253MB