However, application of the principles set forth in this recommended practice can reduce such shock hazards to personnel. Static electricity can be instantaneously removed by grounding. Static electricity and the buildup of static charges are major concerns in many. A grounding electrode conductor gec is used to connect the system grounded neutral conductor, or the equipment to a grounding electrode, or a point on the grounding electrode system.
But the length of time required for static electricity to dissipate varies. Example of correct grounding technique for a static dissipative drum. When a charged object is grounded, the excess charge is balanced by the transfer of electrons between the charged object and a ground. A zero voltage reference or a loopback path is provided for all integrated signals to ensure proper operation or accurate measurements. Static electricity and grounding for dust collection. Static grounding provides a lowresistance ground connection, mitigating the static electricity generation. This document summarizes safety issues related to static electricity, bonding and grounding containers, etc. While it may not always be comfortable to be grounded, and can sometimes even be downright agonizing particularly when one is. Distraction works by focusing outward on the external worldrather than inward toward the self. Only use electrical receptaclesoutlets that have been previously tested using an approved.
This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. Drum containers with oilbased products in a storage room with a static grounding and bonding system employed at that location. You need to define what type of static grounding system is being used and for what. Static grounding receptacles have an internally cast ball also available with a removable ball for attaching the grounding clamp and are supplied with an attached cover. Your company can prevent static ignited fires and explosions with a static ground indicator and interlock system. Grounding of ibc tote with static control monitoring system. Friction between air masses creates static electricity in the cloud formations charges stratify with negative at bottom and positive at top of the clouds low negative layer positively charges ground like opposing plates of a capacitor. Censta orange cable is used to denote single conductor static grounding cables in north america. The purpose of the resistor is to slow down an electrostatic discharge event esd from a highly charged ungrounded surface from discharging instantaneously through the cord. When using reliable bonding and grounding techniques, static electricity should not build up. There are low frequency and high frequency static grounding systems that require different design strategies than conventional grounding systems. Plant engineering static grounding dangerous, preventable.
Even if you dont want to do these practices as your regular exercise, consider learning a few of the breath and movement techniques, as they can help you understand how to connect the upper energies with the lower energies and vice versa. Explain the role of humidity and grounding in static control. Different types of application sketches showing a few of the electrical static grounding techniques and schemes used in industries. Principles of electrical grounding john pfeiffer, p. Read about static control methods including bonding and grounding. These techniques should be strictly followed in areas where flammable and combustible liquids are stored, dispensed or used. Static grounding and bonding applications for control of static.
Using the 54321 technique, you will purposefully take in the details of your surroundings. Grounding serves the primary functions of referencing the ac systems and providing a means to ensure fault clearing. Static bonding and grounding when handling flammable and. If the bonding wire is removed before static electricity is dissipated, a spark is likely to occur. The formation of static electricity is due to the action of contact and separation of dissimilar substances. Grounding is a set of simple strategies to detach from emotional pain for example, drug cravings, selfharm impulses, anger, sadness. However, because nfpa 70 requires a maximum of 25 ohms resistance to ground for equipment grounding, the 25ohm requirement governs for this dual purpose grounding. Ground isolation or conduction can help to reduce noises and electromagnetic interference. Ufc 357501 lightning and static electricity protection.
Nec and the uks bs 7671 list systems that are required to be grounded. Bent wire method use with a hose that is wirereinforced. Dan phelps, one of our senior inspectors and sems consultants, discusses the importance and best practice techniques for effective equipment grounding on modus to ensure your crew is safe and operating under the latest federal regulations. April 2015 objectives on completion of this activity, the reader should be able to. Static bonding and grounding best practices youtube. Static electricity and chemical safety presentation outline. Grounding is the process of removing the excess charge on an object by means of the transfer of electrons between it and another object of substantial size. This is called system grounding and most electrical systems are required to be grounded. A ground is simply an object that serves as a seemingly infinite reservoir of electrons. The book covers the nature of static electricity, characteristics and effective energies of different static resources, techniques for evaluating static electricity hazards, general bonding, grounding, and other techniques used to control static or prevent ignition, gases and liquids, powders and hybrid mixtures. Static electricity what it is how to control remove.
This practice prevents sparking between the bodies. With no static grounding protection in place a truck conducting a vacuuming or loading operation will become electrostatically charged as it has no means of preventing the accumula. When using reliable bonding and grounding techniques, static electricity should not build up during flammable liquid transfer operations. Note that the pump is electrically connected to the bulk drum, the container being filled and the fixed grounding system. Effective grounding and bonding is necessary to ensure safe dissipation of static electricity. Static electricity is electricity but its characteristics create problems which cost industry billions of dollars per year. Trucks are insulated from ground by rubber tires, so when a bonding wire is attached to the tank that is being filled, a continuous path to ground is provided. Not only could a static spark ignite a fire or cause an explosion, but enough charge could buildup in the hose to cause a severe shock if contacted.
Safely dissipating static electricity plastic containers white paper. Static electricity in industry including electrostatic painting. These last two methods are usually not reliable because a good electrical contact is often. Examples include shielding rooms, cables, wirelines, guarded terminals of instruments, transformers and filters. Hazardous locations are particularly important to grounding because they may have flammable or ignitable materials and sparks caused by static could ignite the atmosphere. Static protection through bonding and grounding iaei. How to ground an esd floor learning center staticworx. The earth grounding system connects the house electrical system to the earth. Arising out of static, lightning, and stray currents 6.
Static sparks will readily ignite flammable vapors. This is a path for lightning or static electricity. The earth grounding system uses a wire to connect the service box to the earth with water pipes, grounding rods, etc. It is easy to assume that the use of simple clamps will automatically eliminate the risk posed by static electricity. Grounding cables typically come with 1 meg ohm 1 x 10e6 ohms resistors to ensure that electricity moving through them is always traveling at a static dissipative rate. Static grounding receptacles can be welded directly to a ground rod. A plastic or pvc pipe system cannot be adequately grounded. Static electricity hazards, generation and grounding in industry. Use of a static electricity grounding device is a precaution that can dissipate the charge and minimize the possibility of ignition. There have also been explosions when plastic cans were being filled with gasoline in unlined pickups.
You can also think of it as distraction, centering, a safe place, looking. The basics of grounding electrical systems technical. Grounding conductive and staticdissipative tile and sheet flooring to an ac electrical outlet is the easiest and most common grounding method. This is used to prevent static electricity from being accumulated. Avoiding static ignition hazards in chemical operations. To prevent accumulation of static electricity in conductive equipment, the total resistance of the path to earth grounding path should be minimal to dissipate charges that are otherwise likely to be present. It contains good general principles of safety, but concentrates largely on land based oil storage and transportation. Effective equipment grounding on modus otc offshore.
Static electricity and grounding in hyperbaric chambers robert b. Techniques should be strictly followed in areas where flammable and combustible liquids are stored, dispensed or used. How to control static electricity with proper grounding. Maintaining a good quality equipment grounding system starts with wiring the circuits correctly.
Static electricity accumulation may be significantly increased by the presence of small quantities of water or other contaminants. Your company can prevent staticignited fires and explosions with a static ground indicator and interlock system. Static protection through bonding and grounding iaei magazine. Static protection equipment manual type used for establishing bonding.
Using proper grounding and bonding techniques, testing and maintaining a good electrical ground and installing protection devices are the best ways to protect people and equipment from electrical shock. There are two basic techniques for protecting against the dangers of static electricity. Navy and marine corps aircraft maintenance and operations personnel for the purposes of ensuring that aircraft are properly and safely grounded. In any event, whatever type of ibc is used, it is of paramount importance to ensure any conductive parts that make up the ibc system including the filling pipe, funnels, nozzles and dispensing cans are all bonded and connected to a dedicated static dissipative earth with a continuous resistance of less than 10. Static electricity on hoses causes, hazards and prevention. To reduce potential for static discharge, use proper bonding and grounding procedures. Grounding is an incredibly important skill for anyone with a posttraumatic or dissociative disorder. Static electricity requires grounding a dust collection system which is why air handling systems provides galvanized metal spiral pipe and fittings and flexible hose with wire helix. The importance of equipment grounding offshore equipment often generates high static discharge levels. Static electricity is an imbalance of electric charges within or on the surface of a material or electricity at rest. The function and importance of earth grounding systems. Bonding and grounding flammable iquid transfer figure 2 illustrates the bonding and grounding steps necessary when using a drum pump.
Grounding is implemented to ensure rapid clearing of faults and to prevent hazardous voltage, which in turn reduce the risks of fires and personnel injuries. Grounding means discharging builtup static electricity either directly into the earth, or through a conductor and into the ground. A static grounding system conforming to nfpa 77 is suitable for dissipation of any aircraft static electricity to ground. Static electricity and lightning are two very different problems. Being present and in the here and now is absolutely paramount to a persons physical and mental wellbeing. Grounding is defined as electrical equipment connected directly to mother earth, or to some conducting body that serves in place of the earth, such as the steel frame of an oil drilling platform. Bonding and grounding is a very effective technique for minimizing the likelihood of an ignition from static electricity. However, application of the principles set forth in this recommended practice can reduce such shock. Therefore, grounding the truck in addition to bonding to the tank being filled addresses this issue and is required by osha regulation. These techniques should be strictly followed in areas where flammable and combustible liquids are stored. Reed strongly recommends use of the pegr7 model with pe squeezeoff tools and guillotine pipe cutters and the pegrm static grounding device with magnet connection on ratchet shears in all gas applications. Learn how to incorporate best practices around equipment and processes when draining static electricity from equipment. This document presents current technology in the prevention of hydrocarbon ignition by static electricity, lightning, and stray currents.
1068 267 645 1046 866 737 356 1429 547 1447 189 1579 1320 899 528 799 66 164 727 1023 1372 510 31 631 877 1468 1234 870 878 299 974 618 891 633 356 760 391 1031 310 1123 412