Electrical Distribution Modeling and Power System Studies at a Large Industrial Facility

The client needed a 5-year update on their arc flash labels per NFPA 70E requirements. 

Additionally, the client didn’t have a facility-level EasyPower model and needed this for studies and documentation. They required modeling all the way down to the 208V level on 45kVA and greater transformers to meet their existing corporate specifications.

They also didn’t have consistent documentation of their 200+ MCCs, which made it difficult to figure out which MCCs had space for additional loads.

Delta Wye Engineering was contracted to create an extensive facility model in EasyPower, provide accurate arc flash labels, MCC elevation views, and recommendations around the following:

1. Replacing or upgrading equipment which is overdutied, from the short circuit study.
2. Operation and switching methodology around system contingencies, from the load flow study.
3. Protection relay setting changes to improve coordination and reduce arc-flash incident energy.
4. Maintenance mode settings to reduce arc-flash incident energy during required maintenance procedures.

We conducted 2 week-long site visits to ensure the electrical system data was accurately gathered and modeled.

• A power system model was provided, modeled down to 45 kVA and higher transformers, that feed 208V and higher 3-phase loads. On-site verification was completed for transformers, panels, and MCCs. Testing reports were utilized to verify relay and LV breaker setpoints. SLDs were also created in the new EasyPower model for each substation and provided to the facility.
• A short circuit study resulted in 31 equipment recommendations (8 recommendations at 13.2 kV, 3 recommendations at 2.4 kV, and 20 recommendations at 600 V). The client has started to replace some of these overdutied items, with plans to tackle the rest. This initiative will protect personnel and equipment from being damaged during a fault.
• A load flow study was performed to identify weak points of their distribution system during contingency events. We determined that during islanding or loss of utility transformers, there wasn’t any functional contingency system to bring the power system back to a stable state. We determined that adding a functional load shedding scheme would result in less lost revenue due to blackouts during contingencies such as utility lightning strikes, or loss of utility tie transformers.
• 44 relay and LV breaker settings changes recommended - A coordination study provided the facility with updated TCCs, while making 44 recommendations on relay and LV breaker setting changes to reduce arc flash incident energy or improve coordination.
• 1500 arc flash labels produced - An arc flash study accounted for normal operation, alternate feeds, and maintenance modes. Much of the equipment did not have arc flash labels, but with the updated model approximately 1500 labels were provided to the facility to ensure live work is conducted with the proper PE and to inform personnel of the shock hazards and AF risks. Recommendations were made to reduce arc flash incident energy to below 8cal/cm^2 on 24 pieces of equipment.

We supported the client’s manufacturing facility with a comprehensive power system study and facility wide audit.  

This major update to the facility’s electrical model aimed to ensure accurate modeling for the entire system from the HV utility down to 208V panelboards. Arc flash labels were created and provided to the entire facility, with millions of sq. ft of buildings. 

The study also included field verification of all MCCs and 208V panelboards. All MCCs were modeled using EasyPower’s MCC modeling feature. 

The scope included: 

1. Combining all existing EasyPower models into one comprehensive facility model with a single utility tie connection.

2. Auditing the entire model from 15kV down to 208V during two separate week-long trips, with 2-3 engineers on-site each time.

3. Incorporating recent projects, protection relay setpoints, transformer nameplate information, utility fault data, and field collected data into the updated model.
4. Updating load flow data to match loading from the last 12 months of operations.

A report was compiled with the performed short circuit, coordination, arc flash, and load flow studies, each summarized with recommendations to improve the power system. The updated model was returned, and arc flash labels were shipped to the facility at the end of the project. 

This project ran approximately 1 year from kickoff to final delivery to accommodate various outage schedules and review cycles. 

Kickoff and plan 

• We held a 90-minute kickoff on-site with the senior electrical engineers and corporate electrical engineer to confirm scope, deliverables, site access, and safety requirements. We scheduled additional virtual meetings on an as-needed basis, for deliverable reviews, technical feedback, etc.
• Project was delivered on a fixed price basis, with no change orders.

On-site work 

• We visited the facility 2 times for 18 total days. 

• We completed a site audit of 200+ motor control centers (MCCs), creating elevation views that match the physical layouts.
• While on site we verified transformers, panels, medium-voltage MCCs, and low-voltage MCCs against nameplates and drawings.

• Recent projects (Caustic Area Improvement, Woodyard electrical upgrades, 2.4 kV switchgear replacement) were field-verified and incorporated into the model.

Data and model updates 

• The client shared drawings and records via Microsoft OneDrive and SharePoint. 
• Historian data for a 12-month period was analysed to determine typical full-load operation (about 93 MW) for adjusting the load flow study.

• Generator impedances, transformer ratings, current transformer ratios, and cable data were verified from test reports, oil analysis reports, nameplates, and facility drawings.
• We created a complete set of single-line diagrams for the entire facility that could be printed from EasyPower onto legible 11x17 drawings. 

Collaboration cadence 

• There were frequent conversations to keep the project momentum via emails, phone calls, and meetings. 

• Typical response time was less than 1 day for all requests. 

Review and feedback 

• After completing the on-site MCC audits and model updates from site trips, we issued a progress electrical distribution report within five months.
• After gathering review from the site staff, we delivered a revised report.
• The client reviewed the complete draft and provided feedback, with most feedback collected during a virtual technical review meeting where we walked through the full report, identifying and explaining the most pertinent issues.
• After collecting all client feedback, the final report, model, SLDs, and labels were issued within 1 month.

Closeout and handoff 

• Final deliverables included the updated model, the power system study report (short-circuit, load flow, coordination, and arc-flash), a full set of 11x17 single line diagrams, and ~1,500 arc flash labels. 

• Arc flash study
• Short Circuit Study
• Load Flow Study
• NFPA 70E and IEEE 1584
• Coordination Study
• Power system modeling

• Transformers
• 208V Panelboards
• LV MCCs
• MV MCCs
• Protection Relays

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