Bubble of Protection Complete System Protection ITW Linx A Division of Illinois Tool Works Inc.

Bubble of ProtectionComplete System Protection

ITW LinxA Division of Illinois Tool Works Inc.

©2003

Overview Why Use Surge Protection?

Types of Surges

Technologies

Standards

The “Bubble of Protection”

Bonding and Grounding

Example

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Why Use Surge Protection? Safety

Protect people from electric shock Protect equipment from damage Protect building wiring from excessive

electrical current

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Why Use Surge Protection? Safety National Electric Code

National Fire Protection Association Telecom equipment under Article 800

Primary Protection at Building Entrance Secondary protection

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Why Use Surge Protection? Safety National Electric Code Savings

Blown Equipment Service Calls Downtime Initial Investment with Net Savings

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Why Use Surge Protection? Safety National Electric Code Savings Damaged Equipments

Equals….Headaches Lost Equipment Service Repairs System/Business Downtime Dissatisfied Customers Finger Pointing (Installer, Manufacturer, etc.)

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Why Use Surge Protection? Safety National Electric Code Savings Damaged Equipments

Equals….Headaches Who’s Concerned?

Telephone and Power Companies Facility, Operations, and Telecom Managers Architects, Installers, Contractors,

Technicians Everyone!

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Types of Surges Lightning

Most catastrophic of all surges Does not have to be a direct hit to cause

damage A lightning strike within a few miles can be

induced into aerial or buried cables 10,000,000 Volts 145,000 Amps (145kA)

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Global Lightning Flashes 2000

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Lightning in the U.S. 1989-1998

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Types of Surges Lightning

Power Line Cross Excess current on the Communications line High Risk of Fire Injury to personnel Damage to equipment

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Types of Surges Lightning

Power Line Crosses

Induction Current flow creates a magnetic field Two conductors run parallel and close to one another Field of one conductor can transfer energy to the other

conductor Example: Power is first restored following a blackout

Current

Field

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Types of Surges Lightning

Power Line Crosses

Induction

Electrostatic Discharge Transfer of electrical energy from one material to

another Usually found in dry climates Produces high voltage with low current

Feel sensation at 4kv

Maximum Voltage = 30kV

Enough energy to damage integrated circuits (~35V)

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Shock Thresholds

1mA Perception Threshold

3mA Mild Shock

8mASevere Shock (involuntary muscle movement)

10mA

Freezing Threshold (can’t let go)

35mA

Respiratory Paralysis

65mA

Heart Filtration (no blood flow)

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Technologies Voltage Limiting

Gas Tube Discharge gap between two metal electrodes Poor control of peak voltage Clamping voltages are too high Discharge times are too slow Deposits build on the discharge plates with each

activating surge OK for electromagnetic switches, but not for today’s

electronics

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Technologies Voltage Limiting

Gas Tube Solid State

Provides fast, precise, and long lasting protection Premium alternative to gas tube protectors Fast clamping at low voltages Performance can significantly reduce failure rates for both

protector units and surge sensitive equipment Improved reliability makes it ideal for critical service lines

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Speed of a Surge

How Fast Does Electricity Travel Through A Wire? 186,000 Miles/Second

Number of Feet in a Mile? 5,280 Feet / Mile

Speed (in ft/sec) Electricity Travels Through a Wire 1,000,000,000 ft/sec

Time Required for Surge to Travel One Ft.0.0000000001 Sec.

(1 Nanosecond)

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Speed of a Surge

Device Response TimeDistance Surge Traveled Past Device Before It Responded

Fuse 300,000 ns 300,000 ft

Carbon Block 5,000-10,000 ns5,000 - 10,000 ft

or 1-2 miles.

Gas Tube 4,000-5,000 ns4,000 - 5,000 ft

Or 1 mile.

Solid-State 2 - 5 ns 2 - 5 ft

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Technologies Voltage Limiting

Gas Tube Solid State

Current Limiting Sneak Current Protector Fuses

Prevents the current that passes by the primary protector undetected from burning down building

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Technologies Voltage Limiting

Gas Tube Solid State

Current Limiting Sneak Current Protector Fuses PTC’s

Positive Temperature Coefficient (PTC) Automatically reset once the over current is removed Service calls/costs are dramatically reduced Cost of replacement fuses eliminated

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Standards National Electric Code (NEC)

National Fire Protection Agency for Safety Article 800 - Telecommunications 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

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Standards National Electric Code (NEC) Underwriters Laboratory (UL)

Products listed Do not start on fire or cause a fire to be started, and Do not cause a physical safety hazard to the use

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Standards National Electric Code (NEC) Underwriters Laboratory (UL)

UL497 - Primary Designed to protect against Lightning and Power Crosses

100 Amp, 10/1000

600V, 350A

Three Exceptions Large metropolitan area

Less than 140ft

<5 Thunderstorm days per year

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Standards National Electric Code (NEC) Underwriters Laboratory (UL)

UL497 – Primary UL497A – Secondary

Installed in series between the primary protector and the equipment

Must safely limit over currents

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Standards National Electric Code (NEC) Underwriters Laboratory (UL)

UL497 – Primary UL497A – Secondary UL497B – Isolated Loop (Fire Alarm or Data

Circuit) For lines that are contained within a building and not

connected to the public network outside the building These devices protect against transients usually caused by

electrostatic discharge and electrical shock NOT INTENDED FOR LIGHTNING PROTECTION

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Standards National Electric Code (NEC) Underwriters Laboratory (UL)

UL497 - Primary UL497A – Secondary UL497B – Isolated Loop (Fire Alarm or Data

Circuit) UL1449 – Transient Voltage Surge Suppressor

AC Power listing at 330V For electrical safety, NOT equipment safety

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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?

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Typical Install

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MAIN BUILDING

CAMPUS BUILDING

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“Bubble of Protection” Backwards Approach Three potential conductive paths

1) AC Power 2) Communications Lines (Telecom) 3) Ground System

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Bubble of Protection

LINE

EQUIP

LINE

EQUIP

LINE

EQUIP

LINE

EQUIP

LINE

EQUIP

C.O.

PRI

MARY

LINE

EQUIP

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Final Layout

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Bonding & Grounding Grounding: Establish 0V Reference Bonding: Maintaining 0V Reference

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 Structural Steel Electrical Service Panel

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Bonding & Grounding Ground Impedance < 1Ω

Tightness of Connections (Check Annually) Length (Short as Possible) Number of Bends (Straight as Possible) Bend Radius (Generous) Size/Gauge

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Bonding & Grounding Ground Impedance (Earth Gnd) < 1.0 ohms

Single Point Ground Racks Cable Trays Raised Floor Conduits Structural Steel Equipment Cold Water Pipe AC Panel

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Bonding & Grounding Ground Impedance (Earth Gnd) < 1.0 ohms

Single Point Ground

Protect or Ground Unused Pairs

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Bonding & Grounding Ground Impedance (Earth Gnd) < 1.0 ohms

Single Point Ground

Protect or Ground Unused Pairs

Use proper gauge wire (AWG) Receptacle ground for small systems TMGB for large systems

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Ground Size

Pairs Fuseless Fused

1-2 12 14

3-6 10 14

7-25 6 6

Primary

Secondary Not specified by UL or NEC Check Manufacturer’s Specifications Depends on size of system and current carry

capacity

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Example – Airport Installation

The damaged phone switch

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Example – Airport Installation

A Good Single Point Ground But…

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Example – Airport InstallationIn Another Room, the Ground Wire… IT’S NOT CONNECTED TO ANYTHING!

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Don’t let this happen Don’t let this happen to your systemto your systemDon’t let this happen Don’t let this happen to your systemto your system

Questions?

Contact ITW Linx800-336-5493

www.itwlinx.com