Frame grounding of portable equipment is required by 1227 and 1228 requires testing of all the grounding components at a mine. First, it provides a means of dissipating electric current into the earth without exceeding the operating limits of the equipment. Article 250 covers the grounding requirements for providing a path to the earth to reduce overvoltage from lightning, and the bonding requirements for a lowimpedance fault current path back to the source of the electrical supply to facilitate the operation of overcurrent devices in the event of a ground fault. Ieee std 4872007, recommended practice for the protection of wireline communication facilities serving electric supply locations. This substation grounding course covers effective relaying and insulation of equipment. Some substation designs require fence grounding to be isolated from the main ground grid. The system grounding arrangement is determined by the grounding of the power source. Compliance with all technical requirements all energize elements comply with the required clearances clearances verify compliance with the last requirements of the national electrical safety code or prepa diseno subw\copy of svc subst profile 2. Comments for revision of ieee standards are welcome from any interested. Establish standards and criteria for design, maintenance, repair, and management of grounding and bonding systems in accordance with mandatory requirements of ufc 3. Material requirements grounding systemconductors making up the grounding mat and associated ground risers. Otter tail power company compiled this document with input from others.
There are a number of hazards unique to substations. Grounding products and systems hicks lightning protection. The substation grounding system is an essential part of the every electrical system. Pdf grounding system design in electrical substation. The input for a distribution substation is typically at least two transmission or subtransmission lines. Substation earthing system design optimisation through the. Assessment communicators as part of the oversight strategy for grounding systems. This paper gives suggestions for audit topics and offers practical examples for the setting of standards for wound care services. The topic of system grounding is extremely important, as it affects the susceptibility of the system to voltage transients, determines the types of loads the system can accommodate, and helps to determine the system protection requirements. This bulletin is an update and revision of previous rea bulletin 651, design guide for rural substations revised june 1978. 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.
Our customers for substation safety equipment regularly pose questions relating to safety protection during substation operation and maintenance. Major substation earthing design, construct and commissioning. The substation design manual is not intended to replace asset management standards, but rather to act as a reference document that crossreferences existing standards and process documentation and plugs any gaps where asset management documentation does not exist. Osha grounding requirements for portable and vehiclemounted generators state the following.
What are the requirements for grounding temporary substation fencing. Material requirements grounding systemconductors making up the grounding mat and associated ground risers, andor for encasement in concrete shall be no. Ansiieee std 802000, ieee guide for safety in ac substation grounding. Substation earthing and bonding and their integration into a substation and the potential impacts on third party owned assets in the immediate vicinity of the substation. Technical specification for earthing and bonding at. The intent of this guide is to provide guidance and information pertinent to safe grounding practices in ac substation design. Technical specification for secondary substation earthing. Distribution substation a distribution substation transfers power from the transmission system to the distribution system of an area. The intent of ieee standard 80 is to provide guidance and information pertinent to safe grounding practices in ac substation design. The principal function of the system ground, or grounding electrode, ground rod, is lightning protection for equipment nec article 250. The grounding method shall be made in accordance with the grounding methods of section 9. So, grounding system is required essentially for all power system 1.
Requirements that apply to all sections of division 26. Grounding products and systems technical section69 80 ph. The grounding requirements of a power system will vary from those of electrical equipment, lightning protection or for the. Groundingandbonding nationalelectricalcode article250 byjim. Tying the fence ground into the main ground grid, as shown in fig. Substation engineers must accurately assess the condition of grounding systems to ensure they are capable of dissipating additional fault current.
Ieee standard 80, guide for safety in ac substation grounding, which defines methods for calculating safe touch and step potential, and is widely used in the transportation industry for traction power substation grounding. Pdf the main purpose of this work is the development of an optimization model for the design of the grounding grid in electrical substations. General requirements a conceptual grounding design study is required that will satisfy the following requirements. This guideline applies to rooms that contain medium voltage unit substations, and as appropriate, to rooms with large transformers, large power panels, emergency power distribution equipment. Besides changing the voltage, the job of the distribution substation is to isolate faults in either the transmission or distribution systems. Otter tail power company guidelines for generation, tieline, and substation interconnections ii. Guide for measuring earth resistivity, ground impedance, and earth surface potentials of a ground system. Principles of electrical grounding john pfeiffer, p. All rus borrowers rus electric staff effective date.
M8mt3003 temporary protective grounding for personal protection on overhead lines, 69 kv and above transmission supervisor briefing sheet sbst0609, revision to substation access training requirements supporting programs and databases programs and databases that support performance of activities directed by this procedure. Provide a safe and costeffective conceptual grounding system design for the substation by means of accurate calculations properly accounting for a realistic approximation of the soil structure typically. As the skin becomes moist, the contact resistance drops. The basic requirement for grounding to protect employees against hazardous differences in potential can be found in wac 296453453. Substation grounding training the electricity forum. A shortduration difference in potential between conductive objects that a person may contact when personal protective grounds or a grounding system conduct fault current. Grounding of industrial and commercialpower systems. When the electrical contact is such that the circuit path through the body is across the heart, you have the greatest potential for death. Scope this document states the functional requirements with regard to substation earthing and bonding, and integration into a substation, as well as items that. In section 9, rule 096a, the nesc suggests that the grounding system of a supply station may be extensive, consisting of multiple buried conductors, grounding electrodes, or interconnected combinations of both. Distribution substations may also be the points of voltage regulation, although on long distribution circuits several kmmiles, voltage regulation equipment may also be installed along the line. Site considerations for equipment installation, grounding, and wiring manual d301452x012 october 2019 ii device safety considerations reading these instructions before operating the device, read these instructions carefully and understand their safety implications.
Substation grounding system typical shock situations conditions of danger structure touch electric circuit for switch operator sources of hazardous current on deenergized equipment grounding and jumpering requirements iee std 802000 international and local regulations ieee 802000, ieee guide for safety in ac substation grounding, 2000. Pdf seasonal influences on safety of substation grounding. Step 2 based on experience and on the substation ground bonding requirements, a preliminary economical grounding system configuration is developed and analyzed using the malt grounding analysis computation module based on the equivalent soil model developed in. Ground check monitors for underground power systems. Section 26 05 11, requirements for electrical installations.
This document is published in accordance with the requirements of chapter 5 of the national electricity. Ieee guide for safety in ac substation grounding ieee std. A conducting connection, whether intentional or accidental, between an electrical circuit or. Td703 revision 6 temporary protective grounds for td. Distribution substations michigan technological university. Site considerations for equipment installation, grounding. Fence grounding n the national electrical safety code requires grounding metal fences used to enclose substations with energized electrical conductors or equipment. Adding a ground rod to a portable generator introduces a shock hazard as can be seen in the illustration.
The proper grounding of a substation is essential and very important for the following two reasons. I certify that these students have met the requirements for format contained in the. The basic requirement for grounding to protect employees against hazardous differences in. Review of substation grounding practices, safety and constructability enhancements authors. Distribution voltages are typically medium voltage, between 2. This document is part of the construction virtual manual maintained by document control. Section 1226 requires grounding of substation enclosures. In addition to substation projects, joe is active in standards work both at xcel energy and in ieee. The problem is formulated as a mixedinteger linear. Also connect the new substation to building steel, the associated incoming duct bank when a new duct bank entrance is installed, and to all water services.
Substation design instruction sdi 528 substation signs and equipment labels substation maintenance instruction smi 100 minimum requirements for maintenance of transmission and zone substation equipment substation maintenance instruction smi 104. Personal protective grounding for electric power facilities. Nfpa, standard for fixed guideway transit and passenger rail systems. One of the reasons that designing grounding systems to protect humans is a difficult task is because a critical part of the design is based upon how much current the human body can tolerate. Ic 8767 1978 guide for the construction of drivenrod ground beds. Ic 8835 1980 guide to substation grounding and bonding for mine power systems. Review of substation grounding practices, safety and. Seasonal influences on safety of substation grounding system article pdf available in ieee transactions on power delivery 183. Provide a safe and costeffective conceptual grounding system design for the substation by means of accurate calculations properly accounting for a. Substation design instruction sdi 528 substation signs and equipment labels substation maintenance instruction smi 100 minimum requirements for maintenance of transmission and zone substation equipment substation maintenance instruction smi 104 major substation earthing system test.
Section 26 05 26, grounding and bonding for electrical systems. Otter tail power company gratefully acknowledges permission granted by northern states power and georgia power company to utilize. May 15, 2015 the specific purposes of this guide are to. In parts 55, 56 and 57, section 1225 requires frame grounding of all electrical equipment. Over the years grounding design terms and definitionsprocedures have been developed as well as appropriate standards, most notable. Article 250 grounding and bonding mike holt enterprises. The design is based on the measured soil resistivity of the substation site and proposed methodology is found to be safe for operation. In some situations, improperly using this device may result in damage or injury. Index terms substation, grounding, grounding system. Application of ieee 8020 safety in ac substation grounding including safety in grounding, range of.
Feb 29, 2016 our customers for substation safety equipment regularly pose questions relating to safety protection during substation operation and maintenance. Earthing standards there are a variety of national and international standards available, which. Review of substation grounding practices, safety and constructability enhancements. Connections to the tmgb shall be made by exothermic welding or by listed twohole. Guidelines for generation, tieline, and substation. Pdf simplified method for substation grounding system design.
Substation grounding is a critical part of the overall electric power system. Ieee guide for safety in ac substation grounding ieee std 802000. Install all cable tray to meet the grounding and bonding requirements of nec articles 110. Operational and safety considerations for light rail dc. A substation standards conduit installation details 39. Electric power system grounding 3phase power systems reasons for grounding and bonding substation, transmission, and distribution grounding power faults and lightning strikes fault current distribution ground potential rise gpr touch and step potentials safety 2 d ng. Pdf guideline for earthing of substation researchgate. Presentation outline electric power system grounding 3phase power systems reasons for grounding and bonding substation, transmission, and distribution grounding power faults and lightning strikes fault current distribution ground potential rise gpr touch and step potentials safety 2 d ng. This practice is called grounding and it is done to limit the voltage imposed by lightning, line surges, or unintentional contact with highervoltage lines and to stabilize the voltage to earth during normal operation as documented by 250. The terms connect and bond are used interchangeably in this section and have the same meaning. The main purpose of this work is the development of an optimization model for the design of the grounding grid in electrical substations. As shown in figure 1, the human bodys resistance varies from as low as 500 ohms to as high as 600,000 ohms.