Power System Study

The facility was past the 5 year NFPA 70E requirement for an arc flash study, so an  update was needed to stay in compliance with NFPA legislation. The client had an electrical engineer on staff, but doing a site-wide arc flash study was beyond his expertise and he’s always swamped with just keeping the place running. 

Further, the engineer knew of many motors that had been changed, and projects that had been completed since >5 years ago, but the model wasn’t up to date. 

He reached out to us after we were recommended for our high-quality work and ease of collaboration. Our team had completed site-wide arc flash studies at several other facilities for the same corporation.

We supported the client’s manufacturing facility with a comprehensive medium-voltage (MV)  power system study. 

This once-in-five year update to the facility’s electrical model aimed to ensure accurate arc flash incident energy (AFIE) labels were created and provided to the facility. 

The study also modeled all MV motors, verified that MV equipment was properly rated and coordinated, and identified opportunities to enhance electrical reliability and personnel safety.

A report was compiled with the performed short circuit, coordination, and arc flash studies, each study provided recommended improvements for the power system. The updated model was returned, and arc flash labels were shipped to the facility at the end of the project.

The client shared that the team at Delta Wye Engineering made a complex, infrequent study feel smooth and manageable. They appreciated our proactive communication and the way we kept the project moving even when their availability was limited. Our expertise was highly valued and left them enthusiastic about continuing the partnership in the future. 

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

This once-in-five year update to the facility’s electrical model aimed to ensure accurate arc flash incident energy (AFIE) labels were created and provided to the entire facility, with millions of sq. ft of buildings.

The study also modeled all MV motors, verified that MV equipment is properly rated and coordinated, and identified opportunities to enhance electrical reliability and personnel safety.

The scope included:

1. updating the EasyPower® model with 187 individually field-verified MV motors, 
2. auditing the model by field-verifying any mismatches between the facility SLDs and model, providing drawing redlines where applicable
3. incorporating recent projects, field relay setpoints, and Entergy utility fault data into the updated model, 

A report was compiled with the performed short circuit, coordination, and arc flash 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.

Key findings included:

• the identification of certain overdutied equipment, 
• recommended relay setting changes to resolve miscoordination and reduce AFIE on critical 2.4kV PDCs, 
• potential maintenance mode adjustments to decrease incident energy levels where possible. 

This project ran 17 weeks from kickoff to final delivery.

Kickoff and plan

• We held a 90-minute kickoff on-site with the senior electrical maintenance 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.

On-site work

• We visited the facility 1 time for 4 total days.
• While on site we walked down all electrical rooms, the HV substation, and all process areas that contained MV motors. 
• Data collected for the model included: transformer nameplates, all MV motor nameplates, all MV breaker nameplates, and MV protective device settings.
• In cases where data between the one-lines and the existing model didn’t match, we performed field audits to get accurate data. This was performed for several MV cables, overhead distribution lines, smaller distribution transformers, transfer switches, and various other electrical equipment.

Data and model updates

• The client shared drawings and records via Microsoft OneDrive.
• We incorporated new projects, field-verified relay setpoints, and utility fault data. We then reconciled the model to single-line diagrams with redlines where needed.
• We field-verified 187 motors, and updated the model accordingly.

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

• We delivered final redlines to the facility’s single-line-diagrams 10 weeks after project kick-off.
• We delivered the fully complete draft report after 11 weeks with draft short-circuit results, coordination plots, and arc-flash incident energy results, and recommendations for improvements.
• The client reviewed and provided feedback on the draft report within 2 weeks. Feedback came through a virtual meeting with a list of items to review. PDF markups were made during the virtual meeting.
• We completed the final deliverables 4 weeks after receiving feedback on the draft.

Closeout and handoff

• Final deliverables included the updated model, the report (short-circuit, coordination, and arc-flash study results with recommendations), and updated single-line diagram redlines, and 1062 arc-flash labels.