Grounding Practices for Traffic Control Systems
|
|
- Christina Adams
- 5 years ago
- Views:
Transcription
1 2014 Grounding Practices for Traffic Control Systems Induced surge currents and transient over-voltage occurring on power and signal lines account for a large percentage of damage and mis-operation of traffic control systems if multi-grounded and unprotected. This Tuesday Traffic tip is from the May/June 2010 edition of the IMSA Journal, written by Alan Rebeck and Daniel Lawlor September 16, 2014
2 Grounding Practices for Traffic Control Systems By Alan Rebeck and Daniel Lawlor Introduction Induced surge currents and transient over-voltages occurring on power and signal lines account for a large percentage of damage and mis-operation of traffic control systems if multi-grounded and unprotected. These occurrences, lasting only a short period of time, can be produced by lightning, power companies switching feeders or capacitor banks, or load switching at customer facilities. Single-Point Grounding Problems like these can be avoided by implementing a single-point grounding system, following the National Electrical Code (NEC) when installing the safety (equipment ground) and grounding electrode systems, and the use of a properly designed and selected surge suppressor. (See Figure 1) often located near or mounted on a power pole. The NEC requires that all earth ground references be directly bonded to the original Neutral-Ground bond. Ground Ring. This system is comprised of a minimum #2 AWG, bare wire buried no less than 30-in. under the soil surrounding a structure or pad mounted equipment. The ring ground gives more of an equal-potential ground around the facility. It s almost always supplemented with earth ground rods. (See Figure 2) Figure 2 Figure 1 Concrete Encased Electrode. Metal bars encased in concrete in contact with the surface of the earth. Also known as an Ufer ground. The foundation installed for a traffic control cabinet constitutes additional earth grounding. (See Figure 3) Within a traffic control cabinet, this is normally accomplished for the enclosure and internal system components by use of an equipment ground bar connected to a local earth ground system. Lightning problems arise, however, when the required neutral-ground bond at the first disconnecting means is some distance away and referencing a different earth ground system, typically a driven rod at a power pole installed by the utility. An additional Neutral-Ground bond at the traffic control cabinet will cause many amps of current to be diverted to the equipment grounding conductor from the bond in the disconnect switch. Changes in this objectionable current create voltage spikes or transient overvoltages in the cabinets any time you have a fast changing current in a wire you have spiking. Earth Grounding Techniques The NEC allows a single-point grounding system to be connected to the earth in seven different ways: Rod and pipe electrodes. About 90 percent of all grounding electrode system installations are rod and pipe electrodes. Generally, this is comprised of an 8 to 10 foot stake driven into the earth that extends up and connects to the Neutral conductor at the first disconnecting means which in the case of a traffic control system will be a main disconnect switch Page 28 Figure 3 Other legal grounding electrode systems include: Grounded metal building frame Plate electrodes metal plates buried in the earth for a larger surface area Supplemented metal underground water pipe although the code doesn t allow the use of an underground water pipe by itself anymore, this can be used as a secondary or third connection to the earth Underground local metal structures (exception: gas piping). Continued on page 30
3 Case Study Findings: An electrical power, grounding and transient overvoltage protection inspection was performed on October 7, 2008 by RO Associates. for the City of Hamilton at the First Road and Mud Street intersection (Photo 1). The main objective of the inspection was to determine the cause of frequent lightning related damage, disturbance and degradation of electronic components of traffic control systems located throughout the city. Additional objectives were the recommendation of more effective grounding and bonding topologies and improved lightning surge protection. Continued from page 28 pliance with accepted installation practices, measured voltages, currents, harmonic distortion and electrical noise and inspected lightning and surge protection schemes. Test equipment used during the inspection included a power line analyzer/scope, AC/DC clamp-on ammeter and earth ground impedance tester. Assisting in the inspection was Daniel Lawlor, Project Manager of Traffic Electrical Systems for the City of Hamilton. The system inspected consisted of a TS-1 Fortran traffic control cabinet (Photo 2) and numerous traffic lights supported by metallic poles. Damage has primarily been sustained by the 120 Vrms power supply and data communication interfaces associated with the timer and conflict monitor. Page 30 Photo 1 Hamilton is situated on Lake Ontario and is rated as the third highest city in the country for lightning activity according to Environment Canada s website. In particularly active years the City has lost thousands of dollars worth of sensitive electronic traffic control equipment. For this reason the City has conducted an earth resistivity study, developed new grounding methods using conductive concrete as an enhancement material and has established new engineering standards for grounding and bonding traffic signal equipment. The City called upon RO Associates to conduct a case study and to provide recommendations which have factored into the development of its new standards. It is important to note that while there are many similarities, Hamilton is governed by the Canadian Electrical Safety Code rather than the NEC; furthermore, an Ontario Provincial Standard exists which specifies grounding and bonding recommendations for traffic signal equipment; and finally the Electrical Safety Authority in Ontario permits double bonding of ground and neutral for traffic signal controllers in order to allow manufacturers to comply with the NEMA TS-1 specifications for traffic controllers (the document shows a N-G bond in the power supply portion of the traffic controller circuitry). The reader is cautioned to bear in mind that local standards and codes may vary and take precedence. During the inspection the RO Associates Engineer checked for proper wiring of the AC power distribution, surveyed the grounding scheme for code compliance, verified com- A 30 Amp breaker in the traffic control cabinet is supplied 120 Vrms, single-phase power from a 30 Amp, fused disconnect switch located in an enclosure near a utility power pole located approximately 100 from the cabinet (Photo 3). There is no incoming data communications cable from a cabinet at another intersection to this particular cabinet. Photo 2 A neutral-ground bond to both a driven rod and a buried plate is installed at the 30 Amp disconnect switch, which is proper for a first disconnecting means. The phase and neutral from the disconnect switch to the cabinet are both #10 AWG, insulated, Photo 3 stranded conductors. The equipment grounding conductor is a #6 AWG, green insulated stranded conductor. Measuring at the cabinet (Photo 4), phase-neutral voltage measured low but within allowed limits at Vrms with total voltage harmonic distortion of 3.7% thd. Most manufacturers specify 120 Vrms + 5%/ -10%. IEEE Standard 519 allows a maximum of 5.0% thd for voltage harmonic distortion. Neutral-ground voltage measured 2.7 mvrms. Phase current measured 2.9 Amps with total current harmonic distortion of 7.2% thd. Current in the neutral conductor measured only Continued on page 32
4 Continued from page Amp due to an additional N-G bond at the cabinet also causing a ground loop current of 2.0 Amps to flow in the equipment grounding conductor from the disconnect switch. There is also a small clearance from the neutral bar to the cabinet frame by means of isolating washers. 1.2 and 0.9 Ohm. Impedance to earth from the nearby signal light pole measured 3.7 Ohms proving that it is not bonded to the traffic control cabinet earth grounding system. The U.S. National Electrical Code recommends a maximum of 25 Ohms for touch safety and telecommunications and PLC industry standards require a maximum of 5.0 Ohms for logic reference purposes. A filter type, surge protective device was installed for transient overvoltage and lightning surge protection of the AC power supplied to the cabinet. An MOV type, surge protective device was installed for lightning surge protection of a data communications interface if utilized. Summary: Storm related damage to the City of Hamilton traffic control system inspected can be attributed to: Lack of a local earth ground reference for the traffic control cabinet Photo 4 No current was detected in the grounding electrode conductor to the driven rod and plate at the 30 Amp disconnect switch, however, as previously cited 2.0 Amps was measured in the equipment grounding conductor to the cabinet due to a N-G bond in the cabinet. #6 AWG, insulated, stranded bonding conductors from the signal light poles were supposed to connect to the grounding electrode conductor at the disconnect switch but were not bonded to the disconnect switch or the cabinet. An equipment grounding conductor to an aluminum signal light pole nearby the cabinet was observed to be cut. There was no local earth ground reference for the traffic control cabinet other then the concrete pad. The equipment grounding conductor from the disconnect switch was properly connected to the equipment ground bar in the cabinet but this bar is not intentionally bonded to the cabinet enclosure. A DC resistance of 0.6 Ohm was measured from the safety ground bar to the enclosure. Standard NEMA TS-1 defined connectors and cable harnesses provide power and data communications to the timer and conflict monitor. The enclosures of the timer and conflict monitor are intentionally grounded only by means of small gauge, green insulated conductors grounding the connector shells. DC resistance from each enclosure to the ground bar measured 0.01 Ohm and to the cabinet enclosure measured 0.1 Ohm. The data communications surge protective device is grounded to the enclosure and the shield of the protected cable is connected to ungrounded pin 1226 on a terminal block. Previous soil resistivity data for this intersection, with various probe spacing from 0.5 to 15 meters, resulted in readings from 19 to 45 Ohm-meters indicating the existence of a fairly low impedance soil at this location. Using the three-point, 62% fall-of-potential method, impedance to earth from the disconnect switch and the cabinet respectively measured Page 32 Multiple neutral-ground bonds at the disconnect switch and the traffic control cabinet Lack of an adequate earth grounding topology for the intersection Absence of a conductor bond for local earth grounding of the cabinet enclosure Inadequate sized equipment grounding conductors for the enclosures of the timer and conflict monitor. Failure to bond the equipment grounding conductors for the signal light poles to the traffic control cabinet earth grounding system No policy for grounding of master and slave, traffic control cabinet, data communications cable shields Possible filter type only surge protective device (SPD) for transient overvoltage and lightning surge protection of the incoming AC power distribution The significant distance between the 30 Amp disconnect switches and the traffic control cabinets at both sites inspected does not represent a single point ground and is of concern. When lightning strikes or induces a transient voltage rise into utility lines, a large earth potential rise will occur at or near power poles decreasing with distance. The concrete pad that the traffic control cabinets are mounted on represents a concrete encased electrode (Ufer Ground) and will rise differently in voltage than the grounded neutral and enclosure at the disconnect switch. This will cause a significant surge current in the equipment grounding conductor from the disconnect switch to the equipment ground bar in the cabinet. The multiple neutral-ground bonds at the disconnect switch and the traffic control cabinet are causing an objectionable Continued on page 34
5 steady-state current flow in the equipment grounding conductor. During a lightning strike to the utility medium voltage distribution, re-closers will momentarily open and close causing a fluctuation of this current creating a significant voltage spike across the equipment grounding conductor (e = L di/dt). Continued from page Relocate the 30 Amp, disconnect switch from locations on or near the utility power poles and re-install in a lockable, weatherproof enclosure on the exterior of the traffic control cabinet to eliminate the effects of earth potential rise during a lightning event when the utility medium voltage distribution is struck. There was no clearly defined or adequate earth grounding technique for the traffic control system inspected, employing a combination of driven rod and buried plate at the disconnect switch. Significant lightning induced voltages can appear across even small contact impedances due to the potential lightning equalization surge currents involved. For both touch safety and sensitive equipment immunity reasons, the cabinet enclosure must be grounded by means of an appropriate sized bonding conductor. The only equipment grounding conductors for the timer and the conflict monitor are contained in the small gauge wire cable harness. Small gauge wire has significantly more resistance and inductance to the flow of high frequency currents than larger gauge wire. The fast rise time (1-10 usec) and short pulse width ( usec) of lightning surge currents represent a high frequency event resulting in larger voltage rises across conductors they transit and equipment enclosures referenced to these conductors. The bonding conductor from the light poles to the disconnect switch / traffic control cabinet earth grounding system was cut. As grounded neutral and equipment grounding conductors are delivered to each traffic light from the traffic control cabinet, it is important to control instantaneous voltage differences and resulting surge currents between them caused by differing earth potential rise during a lightning event by means of appropriate sized bonding conductors. For effective shielding and avoidance of low frequency power currents flowing in data communications shields, it is important to ground shields at one end only. There appeared to be no standard policy of grounding shields. The shield at the intersection inspected was floating. Best practice is to ground shields only at the master location. The insertion loss indicated on the specification sheet for the AC power surge protective device indicated significant attenuation beginning around 50kHz which would correspond to the standard surge current test waveshape of 8x20 usec (1 / (20 x 10-6) = 50 khz. This would suggest a filter technique dependent upon frequency of the surge current for performance in limiting voltage surges. It could not be determined from the specification sheet whether the hybrid design included metal oxide varistors or silicon avalanche suppressor diodes normally used in surge protective devices that are not frequency dependent. Recommendations The following recommendations are intended to improve performance, reduce downtime and limit storm related damage to all traffic control systems located in Hamilton, Ontario: Page Per Canadian Electrical Code [10-700(2)] install two, 3.0 meter driven rods spaced 3.0 meters apart as close as possible (each within 1.0 meter) to the traffic control cabinet. It is recommended that the two rods be bonded by means of a minimum #2 AWG, bare, stranded, tinned copper conductor, encased in conductive cement (according to manufacturer instructions), at a minimum depth of 0.5 meter below grade. The use of metal plates as earth grounding electrodes should be avoided unless rods cannot be driven due to bedrock. A National Electrical Grounding Research Project concluded that the average earth ground impedance of a vertically driven 8 x 5/8 rod was 12 Ohms and a stranded copper plate buried at 30 was 152 Ohms. 3. Install an isolated, master ground bar (MGB) inside of the traffic control cabinet. Conductors connected to the MGB should be organized according to the PANI concept with surge producing conductors connected to the P zone, absorbing earth ground electrode conductors connected to the A zone, and in this case all other grounding conductors to the non-isolated and isolated N and I zones. Bond the MGB to the closest point of the driven ground rods and associated bonding conductor by means of a minimum #2 AWG, bare, stranded, tinned copper conductor that is connected to the A zone of the MGB. 4. Bond the neutral conductor in the disconnect switch to the enclosure of the disconnect switch and to the A zone of the MGB by means of a minimum #6 AWG, green insulated, stranded copper conductor. 5. Remove the bonding conductor between the neutral bar and equipment ground bar in the traffic control cabinet. Create a minimum 0.25 clearance between the phase, neutral and equipment ground bars from the traffic control cabinet enclosure. 6. Bond the enclosure of the traffic control cabinet to the N zone of the MGB by means of a minimum #8 AWG, green insulated, stranded copper conductor. 7. Bond the equipment ground bar to the I zone of the MGB by means of a minimum #8 AWG, green insulated, stranded copper conductor. 8. Bond the enclosures of the timer and conflict monitor to the equipment ground bar by means of minimum #10 AWG, green insulated, stranded copper conductors. The PANI concept need not be followed for the equipment ground bar. 9. Bond all signal light poles together and as they are possible strike points for lightning to the P zone of the Continued on page 36
6 MGB by means of minimum #2 AWG, green insulated, stranded copper if in conduit and bare, stranded, tinned copper if direct buried. This may be done in a daisy chain, loop configuration around the intersection with both ends of the loop connected to the P zone of the MGB. Unavoidable ground loop currents are not a concern in bonding conductors that reference different earth ground potentials, as they are in equipment grounding conductors. 10. All cable shields can potentially conduct lightning equalization currents. For master traffic control cabinets, ground the shields of all data communications cables to the P zone of the MGB. Float the shields at all slave master control cabinets. 11. Replace what appears to be a filter type, frequency dependent surge protective device (SPD) for transient overvoltage and lightning surge protection of the 30 Amp, 120 Vrms, single-phase power supply with a nonfrequency dependent SPD. Silicon avalanche suppressor diode (SASD) technology is recommended for its fast response time, low voltage clamping and non-degrading characteristics. The SPD should be fused and wired according to the recommendation of the manufacturer with leads as short as possible to the point of protection. Ground the SPD to the N-G bond in the disconnect switch or the P zone of the MGB depending upon point of application. Continued from page 34 was to keep transient energy away from and out of the controller. Unfortunately, this results in a grounding topology which is inferior from the perspective of step and touch potentials as well as electrostatic discharge. Furthermore, the function of the power supply SPD located inside the controller cabinet will be seriously compromised due to the long, high impedance path to earth via the service bond and ground connections. Finally, this topology fails to consider that transients will also enter the controller on the communications and signal cables and the SPD protecting these conductors will have no local, low impedance grounding path to earth. It is a common fallacy that electricity follows the path of least resistance, rather and in accordance with Kirchhoff s law, it follows all available paths in proportion to their relative impedances. Unless a perfect Faraday shield can be established, transient energy can always find its way into any control cabinet through various coupling mechanisms such as conduction and induction - on any wire or cable going in or out. The best protection strategy is to deal with it by establishing a bonded, equipotential earth reference with a single point, low impedance path to ground using the optimum termination sequence known as PANI. This approach will assure improved safety, efficient SPD function and the best possible protection and operation of sensitive electronic devices. 12. Ground the data communications SPD to the P zone of the MGB. Corrective Actions Since this report was filed by RO Associates, the City of Hamilton has completed four major tasks (1) the development of a grounding method using only a single rod buried in ground enhancement material which yields 5 ohms to earth; this is significant for retrofit applications where restricted surface area and the proximity to underground utilities in a dense urban environment limits the maximum size of a grounding array and the number of grounding electrodes that can be deployed (2) a draft version of our new grounding and bonding standards for traffic signal equipment is now in place for the construction of new signalized intersections (3) a custom, service entrance panel has been designed which will employ a high quality SPD and superior grounding and bonding terminal facilities (4) a stray voltage audit has been conducted to assess traffic signal and street-lighting hazards and their relationship to grounding and bonding practices. In 2010 a contractor will be hired to begin repairing and upgrading the existing traffic grounding and bonding infrastructure to comply with our new standards. Historical Note on Grounding Topology and Design Philosophy: Ontario Provincial Standards for grounding traffic signal controllers were based upon the philosophy of redirecting transient energy into the earth near the electrical service panel (which is usually mounted on a utility pole) and then locating the traffic signal control electronics far away from that point - with no local ground reference. The intent Page 36 The City of Hamilton endorses the design philosophy espoused by RO Associates which is in compliance with IEEE recommendations found in their Green and Emerald standards. Furthermore, the City of Hamilton no longer endorses or permits double neutral-ground bonding (at both the service entrance panel and in the traffic signal controller). Alan Rebeck Mr. Rebeck, Director of Engineering for RO Associates, a Smiths Interconnect Protection Technology Group company, holds two Degrees from Rutgers University, including a B.S. in Electrical Engineering. He is a member of the IEEE Power Engineering Society Standards Committee for Surge Protection, the 2008 NEC Task Force on grounding and bonding, the Lightning Protection Institute as well as a U.S. representative to the IEC Surge Protective Devices Standards Subcommittee. He is a regularly featured speaker to many technical associations and conventions throughout the world including the International Municipal Signal Association (IMSA) and has performed more than 300 power, grounding and lightning protection surveys at telecommunication sites and manufacturing plants in more than 30 countries. Daniel Lawlor Mr. Lawlor, Electrical Project Manager for the City of Hamilton, Traffic Engineering Section has an Electronics Engineering Technologist and a licensed electrician. He as over 25 years of hands on experience in the electrical and electronics field and is a member of the Ontario chapter of the IMSA. In 2008 he completed the Ground Systems Design and Testing course at the AVO Training Institute in Dallas, Texas. He has conducted extensive research into the subject of traffic signal equipment grounding and has developed new standards for the City of Hamilton. For course and consulting information, contact , bheinig@roassociates.com or visit com.
Type DH7091 Transient Protection Assembly
Type DH7091 Transient Protection Assembly D3P00801102 Installation Manual PN4.10:DH7091 Revision A June 1991 This manual supersedes the previous issue dated February 1990. In October 2001, company logos
More informationLIGHTNING AND SURGE PROTECTION
White Paper LIGHTNING AND SURGE PROTECTION Lightning and Surge Protection 01/20/17 1 of 7 www.murata.com APPLICATION NOTE: LIGHTNING AND SURGE PROTECTION Because wireless systems are typically located
More informationLIGHTNING PROTECTION
The University of New South Wales School of Electrical Engineering and Telecommunications Industrial and Commercial Power Systems Topic 8 LIGHTNING PROTECTION Aim is to protect: People Buildings and Contents
More informationWhite Paper. AC Surge Protection. Evaluation of Series Element Surge Protective Device for Protection of Electronic Equipment and Systems
White Paper AC Surge Protection Evaluation of Series Element Surge Protective Device for Protection of Electronic Equipment and Systems Richard Odenberg, Research & Advanced Applications, Founder of Transtector
More informationDANGER DANGER: is used in this manual to warn of high voltages capable of causing shock, burns, or death.
Installation/Operation Manual TABLE OF CONTENTS Page UNPACKING AND INSTALLATION Unpacking and Preliminary Inspection...2, 3 Model Number...9 LOCATION CONSIDERATIONS Environment, Equipment Performance,
More informationOutdoor Risk and Equipment Protection
Outdoor Risk and Equipment Protection The proper use of surge suppressors, lightening arrestors, and weatherproof enclosures are critical protection measures for all outdoor wireless and IP video devices.
More informationSession Two: Effective Surge Protection Installation
Abstract Session Two: Effective Surge Protection Installation Phillip Tompson Managing Director, Novaris Pty Ltd This paper provides an outline of how to effectively install surge protection to various
More informationENGR. MARITES R. PANGILINAN, P.E.E.
ENGR. MARITES R. PANGILINAN, P.E.E. WHAT IS LOW VOLTAGE INSULATION COORDINATION AND WHY IT IS IMPORTANT WHERE DO SURGES COME FROM HOW DO SPDs WORK/TYPE OF SPDs SPD SPECIFICATIONS SPD COORDINATION /CASCADING
More informationHyperLink Brand Weatherproof PTZ Camera Lightning and Surge Protector Model: AL-VDP Series
HyperLink Brand Weatherproof PTZ Camera Lightning and Surge Protector Model: AL-VDP Series Applications Pan-Tilt-Zoom (PTZ) analog video cameras Features Individual protection circuits for analog video
More informationBS th Edition wiring regulations Furse overview
BS 7671 18th Edition wiring regulations Furse overview Transient overvoltage protection TRANSIENT OVERVOLTAGE PROTECTION - RISK ASSESSMENT TO BS 7671 Furse electronic systems protection Enhanced solutions
More information2 Principle of lightning protection
2 Principle of lightning protection The system for protecting a building against the effects of lightning must include: bprotection of structures against direct lightning strokes; bprotection of electrical
More informationINTERNATIONAL STANDARD
INTERNATIONAL STANDARD IEC 62305-4 Edition 2.0 2010-12 Protection against lightning Part 4: Electrical and electronic systems within structures INTERNATIONAL ELECTROTECHNICAL COMMISSION XC ICS 29.020;
More informationSPECIAL SPECIFICATION 1864 Pole Mounted Cabinet
1993 Specifications CSJ s 0924-06-221,etc. & 0924-06-223 SPECIAL SPECIFICATION 1864 Pole Mounted Cabinet 1. Description. This specification describes the minimum acceptable requirements for a weatherproof
More informationTel: Web: Lightning and surge protection help pages
Lightning and surge protection help pages Effects of lightning on your home or office Modern Technology has progressed to the point where detecting and preventing surges, has become an exact science -
More informationTechnical Data Sheet Medium Current Power Surge Filters
Technologies Technical Data Sheet Medium Current Power Surge Filters Features High performance surge protector for an operating voltage of 0-220Vac Designed to withstand fault and over-voltage conditions
More informationSECTION SURGE PROTECTION DEVICES. A. Section includes Surge Protection Devices for low-voltage power, control, and communication equipment.
SECTION 26 43 00 SURGE PROTECTION DEVICES PART 1 - GENERAL 1.1 SUMMARY A. Section includes Surge Protection Devices for low-voltage power, control, and communication equipment. 1.2 DEFINITIONS A. ATS:
More informationMICHIGAN DEPARTMENT OF TRANSPORTATION
MICHIGAN DEPARTMENT OF TRANSPORTATION SPECIAL PROVISION FOR GROUNDING, BONDING, LIGHTNING PROTECTION AND SURGE PROTECTION FOR INTELLIGENT TRANSPORTATION SYSTEM EQUIPMENT ITS:CLC 1 of 5 APPR:LWB:DBP:07-31-13
More informationThe following standards are the basis of design, manufacture, and test of SPD equipment: Guide for Surge Voltages in Low-Voltage AC Power Circuits
ENGINEERING BULLETIN Manufacturing & Test Standards for SPDs APT SPD/TVSS are manufactured and tested in accordance with applicable industry standards. UL Marks are found on APT equipment. These are the
More informationPROTEC Z LV the universal solution for transient switching protection for LV motors, generators, transformer LV secundaries, VSD and UPS equipment
PROTEC Z LV the universal solution for transient switching protection for LV motors, generators, transformer LV secundaries, VSD and UPS equipment NTSA has developed the ultimate solution for protecting
More informationDesigning with Thermally Protected TCMOV Varistors for Type 1 and Type 2 UL1449 3rd Edition Applications
TCMOV Varistors for Type 1 and Type What is UL 1449? Underwriters Laboratories standard UL 1449 has become the primary safety standard for surge protective devices (SPDs). It describes the materials and
More informationElectrical Integration of PV Systems. Ridha Hamidi, Ph.D.
Electrical Integration of PV Systems Ridha Hamidi, Ph.D. 1 Many articles in the NEC are applicable to the electrical integration of a PV system, particularly Article 690. 2 The NEC defines the various
More informationGROUNDING & PROTECTION OF NEWER ELEMENTS in TELECOM
GROUNDING & PROTECTION OF NEWER ELEMENTS in TELECOM Newer Element within Telecom Network inevitably mean more electronics on the roadside, on poles and structure, on roof tops and on towers. This paper
More informationALLTEC PROTECTION PYRAMID TM FOR PHOTOVOLTAIC SOLAR FIELD
64 Catalyst Drive Canton, North Carolina, 28716 USA +1.828.646.9290 +1.828.646.9527 (Fax) +1.800.203.2658 (Toll Free) www.alltecglobal.com ALLTEC PROTECTION PYRAMID TM FOR PHOTOVOLTAIC SOLAR FIELD Photovoltaic
More informationWhite Paper Surge Current Characteristics: 570 Hybrid Surge Protective Device
White Paper Surge Current Characteristics: 57 Hybrid Surge Protective Device Surge Current Characteristics: 57 Hybrid Surge Protective Device This document describes the surge current mitigation characteristics
More information1993 SPECIFICATIONS CSJ , ETC. & SPECIAL SPECIFICATION ITEM 6132 ARTERIAL TRAFFIC MANAGEMENT SYSTEM
1993 SPECIFICATIONS CSJ 1685-05-068, ETC. & 1685-02-042 1.0 DESCRIPTION SPECIAL SPECIFICATION ITEM 6132 ARTERIAL TRAFFIC MANAGEMENT SYSTEM THIS ITEM DESCRIBES THE OPERATION AND INSTALLATION OF AN ARTERIAL
More informationInstallation Notes TII Model 341 Protector
Installation Notes TII Model 341 Protector (ATT-IS PEC 32918) for MERLIN Communications System In Range Out of Building (IROB) Station Installation By Trained Technician Only WARNING: Failure to follow
More informationAC Line Voltage Transients and Their Suppression
AC Line Voltage Transients and Their Suppression Application Note January 1998 AN9308.2 [ /Title (AN93 08) /Subject (AC Line Voltage Transients and Their Suppression) /Autho r () /Keywords (TVS, Transient
More informationAppendix D. EMC Installation Guidelines. Safety Considerations. Ferrite Absorbers and P-Clips. General Product Philosophy
Appendix D EMC Installation Guidelines General Product Philosophy The ZETA6xxx was not designed originally for EMC compliance. Therefore, it will require specific measures to be taken during installation.
More informationLightning and Surge Protection of Photovoltaic Installations. Leutron GmbH 2013 Leinfelden-Echterdingen, Germany
Lightning and Surge Protection of Photovoltaic Installations 1 Lightning and Surge Protection for PV Installations 2 Safeguard from Risks Ups, that was the insurance policy of my house!! 3 Why Lightning
More informationTRI-SERVICE ELECTRICAL WORKING GROUP (TSEWG) 07/16/08 TSEWG TP-3: SURGE PROTECTOR PERFORMANCE AND EVALUATION CRITERIA
TSEWG TP-3: SURGE PROTECTOR PERFORMANCE AND EVALUATION CRITERIA SURGE PROTECTION DESIGN. Parallel Versus Series Protection. Surge protectors within the scope of this UFC should normally be of the parallel
More informationLPI SST Surge Filters
LPI SST Surge Filters Features High performance surge protector for an operating voltage of 200-240Vac Designed to withstand fault and over-voltage conditions of up to 85Vac, as per IEC664 Impulse discharge
More informationMICHIGAN DEPARTMENT OF TRANSPORTATION
MICHIGAN DEPARTMENT OF TRANSPORTATION SPECIAL PROVISION FOR GROUNDING, BONDING, LIGHTNING PROTECTION AND SURGE PROTECTION FOR INTELLIGENT TRANSPORTATION SYSTEM EQUIPMENT ITS:CLC 1 of 6 APPR:MDW:JVG:06-08-18
More informationLiebert AccuVar (ACV Series) Surge Protective Device (SPD) (With Noise Filtering) GUIDE SPECIFICATIONS for a Parallel Surge Suppression System
Liebert AccuVar (ACV Series) Surge Protective Device (SPD) (With Noise Filtering) GUIDE SPECIFICATIONS for a Parallel Surge Suppression System Part 1 General 1.01 Summary A. These specifications describe
More informationTECH NOTE #: CPS-1 SUMMARY OF APPLICABLE UL AND IEEE STANDARDS
TECH NOTE #: CPS-1 SUMMARY OF APPLICABLE UL AND IEEE STANDARDS FOR SURGE PROTECTION DEVICES This Tech Note provides an overview of the key standards associated with surge suppressors and AC powerline filters.
More informationSPM Series Plug-in Surge Protector Type 2/3 (Test Class II/III) Single & Three Phase Surge Arresters
The SPM series of modular surge protection devices provides protection of equipment connected to incoming low voltage AC power supplies against the damaging effects of transient over voltages caused by
More informationAn Overview of Surge Protection for the Smart Grid IEEE PES/SPDC WG Matt Wakeham, Chair
An Overview of Surge Protection for the Smart Grid IEEE PES/SPDC WG3.6.13 Matt Wakeham, Chair The document content is of a general nature only and is not intended to address the specific circumstances
More informationGLOSSARY OF TERMS. Surge and Lightning Protection ERICO Inc.
GLOSSARY OF TERMS Surge and Lightning Protection ERICO Inc. Air Termination - shall mean that part of a lightning protection system designed to capture the lightning strike. Normally is mounted on the
More informationGE Digital Energy. Power Quality
GE Digital Energy Power Quality INSTALLATION, OPERATION AND MAINTENANCE MANUAL GE TRANQUELL Enhanced Thermal Protection (ETP) Series Wall Mounted Medium and High Exposure Surge Protective Devices (SPDs)
More informationPoint-of-Use Surge Protection
Point-of-Use Surge Protection Point-of-use surge protection consists of a power strip with surge protection circuitry incorporated. Point-of-use surge protection should be used anywhere expensive and sensitive
More informationSTATE OF NEW JERSEY BUREAUS OF ITS ENGINEERING AND SAFETY & DATA DEVELOPMENT DEPARTMENT OF TRANSPORTATION TRENTON, NEW JERSEY 08625
September 2011 STATE OF NEW JERSEY BUREAUS OF ITS ENGINEERING AND SAFETY & DATA DEVELOPMENT DEPARTMENT OF TRANSPORTATION TRENTON, NEW JERSEY 08625 MATERIAL SPECIFICATIONS FOR WEIGH-IN-MOTION SYSTEM The
More informationOperating Instructions
Introduction To protect the signal lines of field devices and systems in the cabinet against lightning. Pepperl+Fuchs covers the complete range of Surge Protection Barriers. Housing types Depending on
More informationIntroduction to Surge Protection
KL Automation Engineering Sdn Bhd Introduction to Surge Protection By Abu Bakar bin Yahya OBJECTIVE 1. To give awareness on lightning and surge effects. 2. To discuss on unexplained surge effect DEGRADATION
More informationInstallation Manual. APEX Series. Silicon and MOV Panel Protection. APEX Series
Installation Manual APEX Series Silicon and MOV Panel Protection APEX Series APEX Series Installation Guide 2 Table of Contents Mechanical Installation 3 Table One - Application Rating 3 Figure 1 - Mounting
More informationTotal Home Surge Protection for Point-of-Entry. FirstSurge TM. User Manual - Canada (English)
Total Home Surge Protection for Point-of-Entry FirstSurge TM User Manual - Canada (English) www.siemens.ca/surge Introduction Thank you for choosing the Siemens FirstSurge Residential Surge Protective
More informationNational Standard of The People s Republic of China
Translated English of Chinese Standard: GB/T17626.5-2008 Translated by: www.chinesestandard.net Wayne Zheng et al. Email: Sales@ChineseStandard.net ICS 33.100 L 06 GB National Standard of The People s
More informationSPM Series Plug-in Surge Protection
SPM Series Plug-in Surge Protection The SPM series of modular surge protection devices provides protection of equipment connected to incoming low voltage AC power supplies against the damaging effects
More information1. Section Lightning Protection for lightning protection system. D. The installation shall be in conformance with NEC Article 285.
SECTION 26 04 75 - SURGE PROTECTION DEVICES PART 1 - GENERAL 1.1 SUMMARY A. Applicable provisions of the General Conditions, Supplementary General Conditions and Special Conditions shall govern work performed
More informationEMC Installation Guide
A P P E N D I X B EMC Installation Guide General Product Philosophy Meeting requirements for electromagnetic compatibility (EMC) compliance will require specific measures to be taken during installation
More informationINTRODUCTION LIGHTNING MAGNITUDE AND FREQUENCY
TRANSIENT LIGHTNING PROTECTION FOR ELECTRONIC MEASUREMENT DEVICES Patrick S. McCurdy Presented by: Dick McAdams Phoenix Contact Inc. P.O. Box 4100, Harrisburg, PA 17111-0100 INTRODUCTION Technology advances
More informationINSTALLATION, OPERATION AND MAINTENANCE MANUAL GE TRANQUELL Series Wall Mounted Low and Medium Exposure Surge Protective Devices (SPDs)
ga GE Digital Energy Power Quality INSTALLATION, OPERATION AND MAINTENANCE MANUAL GE TRANQUELL Series Wall Mounted Low and Medium Exposure Surge Protective Devices (SPDs) 2020005003 (12/09) Page 1 of 18
More informationResidential/Commercial/Industrial
Thank You For Purchasing the BASIC POWER UNIT from the team! 120 Marshalls Creek Road East Stroudsburg, PA 18302 570-872-9666 Residential/Commercial/Industrial IF YOU EXPERIENCE A PROBLEM WITH YOUR PURCHASE,
More informationDeploying surge protective devices (SPDs) in photovoltaic systems. Technical Information
Deploying surge protective devices (SPDs) in photovoltaic systems Technical Information 2 00/09.08 Preface Preface Damages caused by overvoltage s are not only responsible for expensive repair costs; they
More informationSPM Series. Plug-in Surge Protection
SPM Series Plug-in Surge Protection The SPM series of modular surge protection devices provides protection of equipment connected to incoming low voltage AC power supplies against the damaging effects
More informationPower Quality of Commercial Buildings - Advanced
Buildings - Advanced Hartford Steam Boiler One State Street P.O. Box 5024 Hartford, CT 06102-5024 Tel: (800) 472-1866 www.munichre.com/hsb May 2017 Background Power quality is a general term used to describe
More informationMDSP-Series 90kA, 150kA, 300kA Modular Distribution Surge Protector Type 2 Class II Surge Arrester
These modular distribution panel protectors for three phase power systems are designed to prevent damage to electrical distribution systems from mainsborne transient voltages which can occur as the result
More informationDirty Power... A Guide to Surge Suppression & Filtering. Surge & Signal Protection for Business-Critical Continuity. EmersonNetworkPower.
Headquarters Surge & Signal Protection 328 Water Street Binghamton, NY 13901 T: 607-724-2484 T: 800-288-6169 F: 607-722-8713 Surge & Signal Protection for Business-Critical Continuity Dirty Power... A
More informationThe Solid-State Decoupler (SSD)
The Solid-State Decoupler (SSD) Installation Instructions Introduction The Solid-State Decoupler (SSD) is a solid-state DC isolation/ac grounding (i.e., coupling) device design ed for use in conjunction
More informationHazardous Area Protection
Hazardous Area Protection Global Solutions in Hazardous Area Surge and Lightning Protection Intrinsic Safety When instrumentation is installed in a potentially explosive environment steps must be taken
More informationTDS Transient Discriminating Surge Diverters
TDS Transient Discriminating Surge Diverters Surge Protection And Surge Ratings The stress, which an SPD will experience under surge conditions, is a function of many complex and interrelated parameters.
More informationIn the simplest terms, surge protective devices (SPDs) prevent damaging transient voltage surge levels from reaching the devices they protect.
How SPDs Work In the simplest terms, surge protective devices (SPDs) prevent damaging transient voltage surge levels from reaching the devices they protect. A useful analogy makes this clearer. Consider
More informationEngineering Notes. Transient Surges and Surge Suppressor Technologies: Comparing Apples to Oranges. Transient Surges Defined and Discussed 6
Engineering Notes TITLE PAGE Transient Surges and Surge Suppressor Technologies: Comparing Apples to Oranges Metal Oxide Varistor (MOV) versus Silicon Avalanche Suppressor Diode (SASD) Designs Discussion
More informationInstallation Instructions
Installation Instructions (Catalog Number 1771-OD) This document provides information on: Because of the variety of uses for the products described in this publication, those responsible for the application
More informationQuantum Chargers Enhanced AC Line Transient Immunity
Introduction Quantum Chargers Enhanced AC Line Transient Immunity By: Nasser Kutkut, PhD, DBA Advanced Charging Technologies Inc. This white paper outlines the most common AC power quality disturbances
More informationManual for overvoltage protection for LED luminaires rev 1
Kurtatsch, Italy, February 10, 2017 Manual for overvoltage protection for LED luminaires rev 1 Through the introduction of LED luminaires, substantial improvements have been achieved with respect to conventional
More informationOvervoltage Protection
Overvoltage Protection OVR Range FRSOX 0100 03 GB ABB Lightning Protection Group 1 Main causes of transient overvoltages The solution: ABB OVR Surge Protective Device Range Lightning strike A lightning
More informationSystems which use a conventional POTS subscriber line to dial a compatible system and transfer digital data.
PSTN Protection The demand for voice and data communications has never been greater. Today, virtually everyone in the developed world has access to a land-line telephone, which carries their voice or data
More informationGENERAL UL th EDITION BID SPEC: SURGE PROTECTIVE DEVICES Prepared by THOR SYSTEMS, INC.
[Refer to Engineering Notes at End of Spec] Section [16XXX] [264XXX] - SURGE PROTECTIVE DEVICES (SPDs) PART 1 - GENERAL 1.1 SCOPE A. This section includes Surge Protective Devices (SPDs) for low-voltage
More informationData Sheet. Surge protection devices - A technical overview
Data Pack K Issued March 1997 232-5985 Data Sheet Surge protection devices - A technical overview Introduction This data sheet covers the following topics: Types of electrical disturbance. Sources of surges
More informationLPI SG + SS480 Spark Gap Surge Filters
LPI SG + Spark Gap Surge Filters Features High performance surge protector for an operating voltage of 220-277Vac Encapsulated spark gap and technology capable of operation under fault /overvoltage conditions
More information700 Series 200 Amp Clamp Meters
700 Series 200 Amp Clamp Meters #61-700 #61-701 #61-702 1 2 3 6 5 7 4 8 1. Non-contact voltage (NCV) (#61-701 and #61-702) With the NCV tab on the tip of the clamp close to an AC voltage, press the NCV
More informationHUBBELL SPIKESHIELD Wired-In Branch Panels Surge Protective Device (SPD)
HUBBELL SPIKESHIELD Wired-In Branch Panels Surge Protective Device (SPD) Instruction Bulletin 8222-0513B Retain for future use. SPIKESHIELD Wired-In Branch Panels 8222-0513B 05/2012 Table of Contents Precautions...
More informationPOWER QUALITY (UNIT-3) ELECTRICAL TRANSIENT:
POWER QUALITY (UNIT-3) ELECTRICAL TRANSIENT: Transients are disturbances that occur for a very short duration (less than a cycle), and the electrical circuit is quickly restored to original operation provided
More informationGENERAL UL th EDITION DESIGN-BUILD SPEC: SURGE PROTECTIVE DEVICES Prepared by THOR SYSTEMS, INC.
[Refer to Engineering Notes at End of Spec] Section [16XXX] [264XXX] - SURGE PROTECTIVE DEVICES (SPDs) PART 1 - GENERAL 1.1 SCOPE A. This section includes Surge Protective Devices (SPDs) for low-voltage
More informationRL Line/Load Reactors
RL Line/Load Reactors Selection Table, Technical Details & Product Application Guide MTE HARMONIC COMPENSATED LINE/LOAD REACTORS help keep your equipment running longer by absorbing many of the power line
More informationINTRODUCTION TO SPECIFYING SURGE PROTECTION SURGE PROTECTION NOTE 1 INTRODUCTION TERMS PROBABILITY OF SURGES APPEARING:
INTRODUCTION TO SPECIFYING SURGE PROTECTION SURGE PROTECTION NOTE 1 BY PETER WALSH, PE INDUSTRIAL SOLUTIONS ENGINEER INTRODUCTION Surge Protective Devices (SPDs) can protect electrical equipment from harmful
More informationLightning and Surge Protection for PV Systems
Lightning and Surge Protection for PV Systems Application Note (AU) Phillip Tompson Introduction Like all electrical equipment photovoltaic systems can be damaged by both direct and indirect lightning
More informationASCO 920 Remote Control (RC) Switches
Maximum reliability and excellent value ASCO 920 Remote Control (RC) Switches ASCO 920 Remote Control Switch in Type Enclosure The ASCO 920 is designed as a feeder disconnect switch for load capacities
More informationFirst Year Operation Events for EgyptSat-1: Ground Control Station Lightening strike and Protection Measures"
First Year Operation Events for EgyptSat-1: Ground Control Station Lightening strike and Protection Measures" By Prof.Fatma Elhefnawi, Eng. Ahmed Yousef, Prof.Amal Zaki fatma.hefnawi@gmail.com Prof.Dr.Fatma
More informationWith the publication. Make the right connection: Bonding a shielded system. installation
Make the right connection: Bonding a shielded system installation With the publication of the IEEE 802.3an 10GBase-T standard in 2006, Augmented Category 6 (i.e., Category 6A) cabling systems are being
More informationSpecifications for Modular Sound Shadow Sound Masking Sound Management Group, LLC.
Specifications for Modular Sound Shadow Sound Masking Sound Management Group, LLC. 1.01 General Requirements This section details general requirements for plenum sound masking installations. 1.1 Contract
More informationLPI SG + SST Spark Gap Surge Filter
LPI SG + SST Spark Gap Surge Filter Features High performance surge protector for an operating voltage of 220-240Vac Encapsulated spark gap and SST capable of sustaining fault and over-voltage conditions
More informationEthernet Protection A Whole Solution Han Zou, ProTek Devices
Ethernet Protection ------ A Whole Solution Han Zou, ProTek Devices Introduction: As Ethernet applications progress from 10BaseT to 10Gigabit and beyond, IC components are becoming more complicated with
More informationLine Impedance Stabilization Network (LISN)
Model 3816/2 Line Impedance Stabilization Network (LISN) User Manual ETS-Lindgren Inc. reserves the right to make changes to any product described herein in order to improve function, design, or for any
More informationControlesta RCO-Compact
Commissioning NOTICE The details contained in these documents and data can be changed without prior advance notice No part of these documents may be reproduced or passed on without the specific written
More informationOVP2. The Over-Voltage Protector 2 (OVP2) Technical Literature
The Over-Voltage Protector 2 (OVP2) Technical Literature INTRODUCTION The Over-Voltage Protector (OVP) design has been established since 1999 as the premier explosion-proof (Division 1) protection device
More informationModel 7705 Control Module
www.keithley.com Model 7705 Control Module User s Guide PA-696 Rev. D / October 2006 A G R E A T E R M E A S U R E O F C O N F I D E N C E Safety Precautions The following safety precautions should be
More informationCONTENTS 3 EN :2006
3 EN 60950-1:2006 CONTENTS INTRODUCTION...9 0 Principles of safety...9 0.1 General principles of safety...9 0.2 Hazards...10 0.3 Materials and components...14 1 General...15 1.1 Scope...15 1.2 Definitions...17
More informationTHE SURGE PROTECTION SOLUTION
THE SOLUTION Unique product features and benefits never before offered in the surge protection industry POWER QUALITY INTERNATIONAL, LLC 2404 Merchant Ave., Odessa, Florida, USA 33556 (888) 539-7712 PowerQuality.net
More informationCode for Design Protection of Structures Against Lightning
UDC NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA i:f:t~a~:=jt*100 00%filt p GB 50057-2010 Code for Design Protection of Structures Against Lightning Issued on: November 3, 2010 Implemented on: October
More informationIt is acceptable to place all required information in the main element (such as G4010) and delete the sub-elements provided in this template.
6. ENGINEERING SYSTEMS REQUIREMENTS G40 SITE ELECTRICAL UTILITIES SYSTEMS REQUIREMENTS SITE ELECTRICAL UTILITIES TEMPLATE 02/18 Instructions for using this template: There are template files for each UNIFORMAT
More informationSOUTH CAROLINA ELECTRIC COOPERATIVES SECONDARY TYPE 1 SURGE PROTECTIVE DEVICE SPECIFICATIONS Updated/Revised: October 6, 2014
SOUTH CAROLINA ELECTRIC COOPERATIVES SECONDARY TYPE 1 SURGE PROTECTIVE DEVICE SPECIFICATIONS Updated/Revised: October 6, 2014 1.0 SCOPE This secondary Type 1 surge protective device specification covers
More informationSPECIFIC INTERCONNECTION PROTECTION REQUIREMENTS... 5
Central Hudson Gas & Electric Corporation (CHG&E) Interconnection Protection Requirements for Distributed Generators of Greater than 300 kva Connected in Parallel with the CHG&E Electrical Delivery System
More informationAC Line Voltage Transients and Their Suppression
Harris Semiconductor No. AN9308.2 January 1998 Harris Suppression Products AC Line Voltage Transients and Their Suppression Author: Martin P. Corbett Introduction The increasing usage of sensitive solid
More informationThe Polarization Cell Replacement (PCRH)
The Polarization Cell Replacement (PCRH) Installation Instructions Introduction The Polarization Cell Replacement for use in Hazardous Locations (PCRH) is a solid-state DC isolation/ac grounding (or coupling)
More informationMedium Voltage Metal-Enclosed Thyristor-Switched Harmonic Filter Banks
66 Carey Road Queensbury, NY 12804 Ph: (518) 792-4776 Fax: (518) 792-5767 www.nepsi.com sales@nepsi.com Medium Voltage Metal-Enclosed Thyristor-Switched Harmonic Filter Banks General NEPSI's activar, Medium
More informationLiebert TVSS: The First Line of Defense - Product Overview. Jim Tiesi
Liebert TVSS: The First Line of Defense - Product Overview Jim Tiesi INTERCEPTOR SURGE SUPPRESSION Overall Design True modular design Low impedance copper conduction plates Best in class performance Real-time
More informationSURGE PROTECTION OPTION
Reliable Continuous Energy PV FOR TELECOM Installation Guide Gen 4 PVT Panels ENHANCED SURGE PROTECTION OPTION Manual Rev 4.4 Apollo Solar -- Gen 4 PVT Enhanced Surge Protection Option Page - 1 - IMPORTANT
More informationSurge & Filter Protection Addressing your industrial power quality needs.
Surge & Filter Protection Addressing your industrial power quality needs. BULLETIN 983 INTRODUCING SURGE & FILTER PROTECTION SURGE & FILTER PROTECTION Rockwell Automation is pleased to introduce the Bulletin
More information10 Mb/s Single Twisted Pair Ethernet Process Industry Requirements Steffen Graber Pepperl+Fuchs
10 Mb/s Single Twisted Pair Ethernet Process Industry Requirements Steffen Graber Pepperl+Fuchs IEEE802.3 10 Mb/s Single Twisted Pair Ethernet Study Group 9/8/2016 1 Overview Introduction Current bus Infrastructure
More informationBulletin Installation of Solar Photovoltaic Systems Section 50; Rules: , , ; Tables 11 and 19 Issued July 2010
Ontario Electrical Safety Code - Bulletins 50-1-0 Bulletin 50-1-0 Installation of Solar Photovoltaic Systems Section 50; Rules: 84-020, 84-024, 84-030; Tables 11 and 19 Issued July 2010 Scope (1) Introduction
More information