Bubble of Protection Complete System Protection ITW Linx
Bubble of Protection Complete System Protection ITW Linx A Division of Illinois Tool Works Inc.
Overview ~ Why Use Surge Protection? ~ Types of Surges ~ Technologies ~ Standards ~ The “Bubble of Protection” ~ Bonding and Grounding ~ Example © 2003
Why Use Surge Protection? ~Safety a. Protect people from electric shock a. Protect equipment from damage a. Protect building wiring from excessive electrical current © 2003
Why Use Surge Protection? ~Safety ~National Electric Code a. National Fire Protection Association a. Telecom equipment under Article 800 4 Primary Protection at Building Entrance 4 Secondary protection © 2003
Why Use Surge Protection? ~Safety ~National Electric Code ~Savings a. Blown Equipment a. Service Calls a. Downtime a. Initial Investment with Net Savings © 2003
Why Use Surge Protection? ~Safety ~National Electric Code ~Savings ~Damaged Equipments Equals…. Headaches a. Lost Equipment a. Service Repairs a. System/Business Downtime a. Dissatisfied Customers a. Finger Pointing (Installer, Manufacturer, etc. ) © 2003
Why Use Surge Protection? ~Safety ~National Electric Code ~Savings ~Damaged Equipments Equals…. Headaches ~Who’s Concerned? a. Telephone and Power Companies a. Facility, Operations, and Telecom Managers a. Architects, Installers, Contractors, Technicians a. Everyone! © 2003
Types of Surges ~Lightning a. Most catastrophic of all surges a. Does not have to be a direct hit to cause damage a. A lightning strike within a few miles can be induced into aerial or buried cables a 10, 000 Volts a 145, 000 Amps (145 k. A) © 2003
Global Lightning Flashes 2000 © 2003
Lightning in the U. S. 1989 -1998 © 2003
Types of Surges ~ Lightning ~ Power Line Cross a Excess current on the Communications line a High Risk of Fire a Injury to personnel a Damage to equipment © 2003
Types of Surges ~ Lightning ~ Power Line Crosses ~ Induction a Current flow creates a magnetic field a Two conductors run parallel and close to one another a Field of one conductor can transfer energy to the other conductor a Example: Power is first restored following a blackout Field Current © 2003
Types of Surges ~ Lightning ~ Power Line Crosses ~ Induction ~ Electrostatic Discharge a Transfer of electrical energy from one material to another a Usually found in dry climates a Produces high voltage with low current 4 Feel sensation at 4 kv 4 Maximum Voltage = 30 k. V a Enough energy to damage integrated circuits (~35 V) © 2003
Shock Thresholds 1 m. A Perception Threshold 3 m. A Mild Shock 8 m. A Severe Shock (involuntary muscle movement) 10 m. A Freezing Threshold (can’t let go) 35 m. A Respiratory Paralysis 65 m. A Heart Filtration (no blood flow) © 2003
Technologies ~Voltage Limiting a. Gas Tube 4 Discharge gap between two metal electrodes 4 Poor control of peak voltage 4 Clamping voltages are too high 4 Discharge times are too slow 4 Deposits build on the discharge plates with each activating surge 4 OK for electromagnetic switches, but not for today’s electronics © 2003
Technologies ~Voltage Limiting a. Gas Tube a. Solid State 4 Provides fast, precise, and long lasting protection 4 Premium alternative to gas tube protectors 4 Fast clamping at low voltages 4 Performance can significantly reduce failure rates for both protector units and surge sensitive equipment 4 Improved reliability makes it ideal for critical service lines © 2003
Speed of a Surge How Fast Does Electricity Travel Through A Wire? Number of Feet in a Mile? 186, 000 Miles/Second 5, 280 Feet / Mile Speed (in ft/sec) Electricity Travels Through a Wire 1, 000, 000 ft/sec Time Required for Surge to Travel One Ft. 0. 000001 Sec. (1 Nanosecond) © 2003
Speed of a Surge Device Fuse Response Time Distance Surge Traveled Past Device Before It Responded 300, 000 ns 300, 000 ft 5, 000 - 10, 000 ft Carbon Block 5, 000 -10, 000 ns or 1 -2 miles. Gas Tube Solid-State 4, 000 -5, 000 ns 2 - 5 ns 4, 000 - 5, 000 ft Or 1 mile. 2 - 5 ft © 2003
Technologies ~Voltage Limiting a. Gas Tube a. Solid State ~Current Limiting a. Sneak Current Protector Fuses 4 Prevents the current that passes by the primary protector undetected from burning down building © 2003
Technologies ~Voltage Limiting a. Gas Tube a. Solid State ~Current Limiting a. Sneak Current Protector Fuses a. PTC’s 4 Positive Temperature Coefficient (PTC) 4 Automatically reset once the over current is removed 4 Service calls/costs are dramatically reduced 4 Cost of replacement fuses eliminated © 2003
Standards ~National Electric Code (NEC) a. National Fire Protection Agency for Safety a. Article 800 - Telecommunications a. All conductive paths entering or leaving a building shall be protected by a listed primary protector as soon as possible, but no more than 50 feet past the building entrance © 2003
Standards ~National Electric Code (NEC) ~Underwriters Laboratory (UL) a. Products listed 4 Do not start on fire or cause a fire to be started, and 4 Do not cause a physical safety hazard to the use © 2003
Standards ~National Electric Code (NEC) ~Underwriters Laboratory (UL) a. UL 497 - Primary 4 Designed to protect against Lightning and Power Crosses - 100 Amp, 10/1000 - 600 V, 350 A 4 Three Exceptions - Large metropolitan area - Less than 140 ft - <5 Thunderstorm days per year © 2003
Standards ~National Electric Code (NEC) ~Underwriters Laboratory (UL) a. UL 497 – Primary a. UL 497 A – Secondary 4 Installed in series between the primary protector and the equipment 4 Must safely limit over currents © 2003
Standards ~National Electric Code (NEC) ~Underwriters Laboratory (UL) a. UL 497 – Primary a. UL 497 A – Secondary a. UL 497 B – Isolated Loop (Fire Alarm or Data Circuit) 4 For lines that are contained within a building and not connected to the public network outside the building 4 These devices protect against transients usually caused by electrostatic discharge and electrical shock 4 NOT INTENDED FOR LIGHTNING PROTECTION © 2003
Standards ~National Electric Code (NEC) ~Underwriters Laboratory (UL) a. UL 497 - Primary a. UL 497 A – Secondary a. UL 497 B – Isolated Loop (Fire Alarm or Data Circuit) a. UL 1449 – Transient Voltage Surge Suppressor 4 AC Power listing at 330 V 4 For electrical safety, NOT equipment safety © 2003
Risk Assessment ~ Where is the facility (Lightning potential)? ~ What is the Power Quality? ~ Outside Extensions? ~ What is the Ground Quality? ~ How Critical is the System? ~ What Will It Cost to Replace the System? © 2003
Secondary Primary PBX Secondary Primary Protection Telco Demarcation CO LINES Secondary Typical Install CAMPUS BUILDING MAIN BUILDING © 2003
“Bubble of Protection” ~Backwards Approach ~Three potential conductive paths a 1) AC Power a 2) Communications Lines (Telecom) a 3) Ground System © 2003
Bubble of Protection C. O. P R I M A R Y © 2003
Final Layout © 2003
Bonding & Grounding ~ Grounding: Establish 0 V Reference ~ Bonding: Maintaining 0 V Reference a Two Point Resistance < 0. 1Ω ~ Direct attachment to the closest point in the building’s electrical service grounding electrode system is preferred ~ 90% of problems are due to improper grounding ~ Good grounds a Structural Steel a Electrical Service Panel © 2003
Bonding & Grounding ~ Ground Impedance < 1Ω a Tightness of Connections (Check Annually) a Length (Short as Possible) a Number of Bends (Straight as Possible) a Bend Radius (Generous) a Size/Gauge © 2003
Bonding & Grounding ~ Ground Impedance (Earth Gnd) < 1. 0 ohms ~ Single Point Ground a Racks a Cable Trays a Raised Floor a Conduits a Structural Steel a Equipment a Cold Water Pipe a AC Panel © 2003
Bonding & Grounding ~ Ground Impedance (Earth Gnd) < 1. 0 ohms ~ Single Point Ground ~ Protect or Ground Unused Pairs © 2003
Bonding & Grounding ~ Ground Impedance (Earth Gnd) < 1. 0 ohms ~ Single Point Ground ~ Protect or Ground Unused Pairs ~ Use proper gauge wire (AWG) a Receptacle ground for small systems a TMGB for large systems © 2003
Ground Size Primary Pairs 1 -2 3 -6 7 -25 Fuseless 12 10 6 Fused 14 14 6 Secondary a Not specified by UL or NEC a Check Manufacturer’s Specifications a Depends on size of system and current carry capacity © 2003
Example – Airport Installation The damaged phone switch © 2003
Example – Airport Installation A Good Single Point Ground But… © 2003
Example – Airport Installation In Another Room, the Ground Wire… IT’S NOT CONNECTED TO ANYTHING! © 2003
Don’t let this happen to your system © 2003
Questions? Contact ITW Linx 800 -336 -5493 www. itwlinx. com
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