The Industrial Technology Group’s Power Engineering team provides expert development of one-line and three-line drawings to support the design, construction, and maintenance of electrical systems. These drawings serve as essential tools for engineers, contractors, and facility managers, ensuring that every aspect of a power system is clearly documented and easily understood.
One-Line Drawings
One-line drawings offer a simplified overview of an electrical power system. They illustrate the main components—such as transformers, switchgear, panels, and feeders—and show how power flows through the system. This high-level representation helps teams visualize system layout, identify key connections, and plan for safe and efficient operation.

Three-Line Drawings

Three-line drawings provide a more detailed view of the electrical system, showing each phase of power distribution along with wiring, protection devices, and control elements. These drawings are essential for construction and maintenance activities, offering the precision needed for accurate installation, troubleshooting, and compliance with electrical codes and standards.
Why It Matters
Accurate one-line and three-line drawings are critical for:
Safety and Compliance: Meeting industry standards and regulatory requirements.
System Planning: Supporting design decisions and load analysis.
Maintenance: Simplifying troubleshooting and system updates.

Expertise and Quality
ITG’s Power Engineering team combines technical expertise with industry best practices to deliver clear, compliant, and reliable documentation. Each drawing is developed with precision to ensure that electrical systems operate safely and efficiently throughout their lifecycle.










