Services for Business-Critical Continuity
n Avoid unnecessary damage to equipment n Ensure personnel safety n Reduce downtime when a fault does occur n Isolate faulty circuits without loss of power to other parts of the system n Identify under-protected equipment before it’s too late
Short Circuit and Coordination Studies from Emerson Network
Power Service are ideal for facilities undergoing power infrastructure enhancements or facilities that have experienced load changes.
Inadequately rated or uncoordinated protective equipment can cause extensive damage to your systems, lead to prolonged downtime, and even result in personnel injury.
Short Circuit Study — Determines the magnitude of fault current and whether equipment is properly rated to interrupt or withstand the short circuit.
Protective Device Coordination Study — Determines characteristics, settings and sizes to evaluate whether protective devices are coordinated to isolate faulty equipment in a manner which will maintain a balance between equipment protection and selective device operation.

Your critical electrical distribution system is the foundation of your entire operation. Knowing you have an accurate picture of your power system’s ability to safely handle fault conditions is key to achieving the level of availability that is necessary to sustain business continuity.
With our Short Circuit and Coordination Studies,
Emerson Network Power Service will provide a comprehensive, detailed and accurate assessment of your power system’s protective device capabilities.
4. Bringing Down Your Entire Operation
Due to poor breaker coordination the short circuit trips all the way back to the main breaker – shutting power down to your entire facility.
Utility Source
3. Causing Equipment Damage
At minimum, the short circuit destroys the improperly rated breaker. At worst, the arc causes damage to other equipment including switchgear.
1. A Fault Occurs
A faulty piece of equipment in one of your mini-computer rooms creates a
Short Circuit.
2. An Improperly Rated Breaker Arcs
The distribution breaker designed to localize the risk and de-energize the area is improperly rated. The short circuit arcs through the breaker, and escalates up the facility.

Purpose
Determine the short circuit current available at each component of the electrical system and confirm whether the component is rated to withstand and/or interrupt the current. Analyze all possible operating scenarios influenced by additions or changes to the electrical system.
What We Do: n Review panel and device data, feeder sizes and lengths, transformer nameplate information, generator and automatic transfer switch data
(where they exist) and utility source information.
n Perform short circuit analysis, protective device evaluation and protective device coordination.
Studies will be performed using SKM PowerTools for Windows software.
n Identify any suspect equipment, recommended corrective action and device settings to allow for selective coordination of protective devices consistent with system operation.
n Provide a summary table that compares the available fault currents to the withstand rating of the equipment and devices within the study.
n Test the devices at the recommended settings to assure operation within the manufacturer’s tolerances.
What You Get:
A detailed report that includes: n A full description of the basis, purpose and scope of the study.
n Tabulations of the data used to model system components and a corresponding one-line diagram.
n Descriptions of the scenarios evaluated and identification of the scenario used to evaluate equipment short circuit ratings.
n Tabulations of equipment short circuit ratings versus available fault duties. The tabulation identifies percentage of rated short circuit and clearly note equipment with insufficient ratings.
n Conclusions and recommendations.
A short circuit can create unforeseen, unacceptable problems for your facility. Ensuring the proper rating and coordination of your breaker systems reduces unexpected downtime and the risk of equipment damage from short circuit risks.
Purpose
Coordination Studies are performed to ensure minimum service interruption under overload and short circuit conditions.
It will ensure the protective device closest to the overload or short circuit condition is the one that operates in order to isolate the failure as quickly as possible. If the circuit breaker or other protective devices are improperly set too low, then the protective devices may trip unnecessarily causing critical loads to be dropped. Conversely, if protective devices are improperly set too high then the protective device closest to the failure may not trip at all, causing another protective device further upstream to trip –- the result, an outage to a much larger part of your distribution system and possibly even a complete blackout of your facility.
What We Do: n Evaluate and select proper settings or sizes for relays, breakers and fuses.
n Compare the operating levels and times of the protective devices to withstand levels and times that the equipment can sustain without damage or failure.
n Identify and recommend corrective action for under-protected equipment.
What You Get:
A detailed report that includes: n The basis, description, purpose and scope of the study plus a corresponding one-line diagram.
n Time-current curves demonstrating the coordination of time-overcurrent protective devices.
n Tabulations of protective devices identifying circuit location, manufacturer, type, range of adjustment, IEEE device number, current transformer ratios, recommended settings or device size, and referenced time-current curve.
n Conclusions and recommendations.

Batteries
DC Power
Generators
Mission Critical
Cooling
Switchgear
Cr itic al S pac e In fras truc ture
UPS
Emerson Network Power Service
Global Headquarters
610 Executive Campus Drive
Westerville, Ohio 43082 USA
800 LIEBERT or 614 841 6400 Phone
614 841 6405 FAX service@ liebert.com Email liebert.com
Customer Response Center
800 LIEBERT Phone
While every precaution has been taken to ensure accuracy and completeness in this literature, Emerson Network Power
Service and Emerson Electric Power Co. assume no responsibility, and disclaim all liability for damages resulting from use of this information or for any errors or omissions.
Emerson Network Power Service is a division of Emerson
Electric Power.
© 3/2006 Emerson Network Power Service
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