Eaton offers an extensive range of arc flash and coordination studies, including:

Data collection

Eaton performs electrical field studies, arc flash and coordination analysis for new or existing electrical power distribution systems. In addition to electrical power distribution equipment, data collection types include motor, transformers, cable, generators, utility and others. Eaton power system study engineers may request facility electrical system data or can be contracted to collect it for an organization.

Short-Circuit and Protective Device Evaluation Study

For this study, typical conductor impedances based on IEEE Std. 141-1993 are utilized, with transformer design impedances used when test impedances are not available. The study includes:

• Calculation methods and assumptions
• Selected base per unit quantities
• One-line diagram of the system being evaluated
• Source impedance data, including electric utility system and motor fault contribution characteristics

A calculation of short-circuit momentary and interrupting duties for a three-phase bolted fault is made for the following locations:

• Electric utility’s supply termination point
• Incoming switchgear
• Unit substation primary and secondary terminals
• Low voltage switchgear
• Motor control centers
• Standby generators and automatic transfer switches
• Branch circuit panelboards
• Other significant locations throughout the system

For grounded systems, a bolted line-to-ground fault current study will be provided.  

Protective Device Coordination Study

• Proposed protective device coordination time-current curves will be displayed on log-log
• Included on each curve sheet will be a complete title and one-line diagram with legend identifying the specific portion of the system covered
• The device characteristic curves will be terminated at a point reflecting maximum symmetrical or asymmetrical fault current to which device is exposed
• Identification of the device associated with each curve by manufacturer type and function, and generated using a commercially available software program

Arc flash analysis summary details

The arc flash analysis considers each medium and low voltage system location within the scope of the work. Per IEEE standards, no detailed calculations will be performed for 120/208V locations supplied by a transformer smaller than 125 kVA; however, labels will be provided for these locations stating that the incident energy is less than 1.2 cal/cm². For detailed calculations, the software determines the available fault currents for each location and the clearing time of the device protecting the same location. From these determinations, the potential incident energy is calculated for each location. Arc flash computations include both line and load side of main breaker calculations, where necessary.