Service Solutions

Site Survey

Performing an on-site survey of your electrical system is the first step to creating or updating a single-line diagram. Trained HVM technicians collect information to determine the elements that need to be deleted or added in the overall schematic. Doing this creates a building block of knowledge. Once the survey is complete, our team will create a new, professional single-line diagram for your records.

Single-Line Development

The single-line diagram is the blueprint for electrical system analysis. It is the first step in preparing a critical response plan, allowing you to become thoroughly familiar with the electrical distribution system layout and design in your facility. Our engineering team will create a detailed single-line diagram that clearly documents your electrical distribution system design, giving you the documents necessary for electrical system analysis, maintenance, and future modifications.

Single-Line Review and Update

In many facilities, loads are continually added or removed in small increments. The net effect is not always seen until some part of the system becomes overloaded or exhibits other problems. Following a site survey, HVM engineers will update existing single-line diagrams or complete electrical system drawings as needed. This update will incorporate any changes to the infrastructure, note load changes, add missing components, and correct inaccurate information.

Compliance and Safety Check

Many electrical systems transform over time, causing concern for safety issues. That’s why NFPA 70E requires an accurate single-line diagram for each facility. HVM's highly trained professionals put their end-to-end expertise and knowledge of electrical industry code regulations to use to ensure compliance and safeguard your business.


  • Enhanced safety happens as reviews, surveys and checks identify potential risks before a problem occurs
  • Improved effectiveness of critical response plans is possible with an up-to-date schematic of your electrical distribution system
  • Ensured compliance with code regulations happens as single-line diagrams are updated or created
  • More effective future engineering services, which enable performance optimization, are possible when you have accurate system information


  • Extensive experience with site surveys and single-line review, updates and development across all industries
  • End-to-end expertise and knowledge of electrical codes and standards to ensure compliance and safeguard operations
  • Deep infrastructure expertise across the entire electrical system from generation and transmission to distribution and secondary distribution infrastructures
  • Technical knowledge base from completing thousands of jobs over the last 50+ years
  • Documented quality program to ensure standardized and consistent service delivery everywhere you operate
  • Superior safety ratings, safe work practices, and award-winning safety programs
  • Industry-leading customer satisfaction and Net Promoter Score
  • Nationwide staff of registered professional engineers
  • A leader in staffing Level 3 & 4 NETA-Certified technicians
  • Participate and lead standard development including NFPA, IEEE, and NETA
  • Customer resolution center available 24x7x365 for emergency support
  • Comprehensive test equipment calibration program
  • Standardized data acquisition tool deployed across our global service organization, ensuring consistent, standardized data collection across each equipment type anywhere in the world
  • State-of-the-art equipment and diagnostic software and tools
  • Easy-to-read technical reports, compatible with industry standards
HVM Home Page