Through and precise data concerning the system under analysis is indispensable for power system studies. Developing a precise model necessitates gathering input data, typically sourced from existing documentation, field data collection, or a combination of both methods.
Field data collection often involves extracting information directly from the nameplates of electrical equipment. However, obtaining power system data in the field should only be undertaken by qualified personnel. This task may entail accessing energized equipment by removing access panels to gather additional details not available on the nameplate, such as cable sizes and feeder quantities.
The duration of data collection varies based on several factors, including:
- Size and complexity of the electrical system.
- Physical limitations regarding access.
- Quality of available data from existing documentation.
- Availability of personnel for data collection.
The duration of data collection varies based on several factors, including:
- Size and complexity of the electrical system.
- Physical limitations regarding access.
- Quality of available data from existing documentation.
- Availability of personnel for data collection.
While every facility and situation present unique challenges, the following steps can serve as approximate guidelines for the data collection process and over this process we
- Examine available documentation, such as single-line diagrams (SLD) and physical layout drawings, including site plans. While these may be electronically accessible in many cases, older facilities might rely on hard copy documents. Reviewing this information, even if not entirely current, can significantly streamline on-site fieldwork, particularly for arc-flash studies. Helpful documents for such studies include existing single line diagrams and previous electrical system studies, including short circuit, coordination, and arc-flash studies.
- Consult with site staff to address any known documentation issues or system changes they are aware of. Record any available previous system studies, along with shop drawings, bills of materials, and test reports.
- Develop a preliminary single line diagram based on available documentation to gain an overall understanding of the system. Identify any additional data required, noting areas where field data collection is necessary. This preliminary diagram aids in identifying missing data and preparing necessary data collection forms.
- For larger systems, consider creating a rough physical map or layout of key components, such as transformers, sources, switchgear/switchboards, and distribution points (MCCs, panels, etc.). It is essential to utilize inputs from plant engineers, electricians, or existing drawings to develop this preliminary map.
- Based on the preliminary single line diagram and physical layout sketch, compile a list of required data and plan for on-site data collection. Employ data collection forms or templates to streamline the process and ensure accurate record-keeping.
- Coordinate with plant team for the site visit and enlist the assistance of a site electrician familiar with the facility’s layout. Note any challenges regarding equipment access or potential interference with plant operations.
- Utilize a digital camera during data collection to capture detailed images of equipment and nameplates. These visuals can provide valuable context and aid in understanding equipment data.
- Record equipment ratings from nameplates and photograph them whenever feasible.
- Document the range of available settings and current settings for equipment with adjustable settings, noting the status of switching devices (open or closed).
- Develop a comprehensive single line diagram illustrating all equipment, such as utility connections, transformers, cables, switches, circuit breakers, fuses, and loads. Ensure accurate interconnection representation and label each equipment item with its corresponding ID name and relevant data.
- Engage with plant personnel to leverage their knowledge of the facility, seeking input from multiple individuals as needed.
- Verify data from previous studies, settings, or drawings, as the facility may not have been updated or equipment settings may have changed.
- Clarify the purpose and scope of data collection before commencing, ensuring alignment with the study objectives and areas to be modeled.
- Strive to collect all necessary data during each area visit to minimize the need for subsequent site visits or data requests. Capture photographs of equipment whenever possible.
Upon gathering electrical system data, a comprehensive electrical system model is created, and equipment details are inputted into specialized software tailored for power system analysis. Subsequently, a detailed report is generated. The engineer overseeing the study meticulously reviews and approves the final output.
Get answers and advice
Our goal is to answer all your questions in a timely manner.