Substations & Switchyard

Mesa’s Power Delivery design capability encompasses all transmission/distribution voltage levels, from extra high voltage to distribution levels, as well as both open air-insulated and metal clad designs. The highly qualified and experienced Mesa staff of engineers and designers provides a full range of Power Delivery services to our clients. Mesa has employees with a combined total experience of over 5,500 years for many utilities across the U.S.

In the past five years, Mesa has documented cost savings exceeding $11M to a large electric utility. These savings have come in the form of improvement in unit costs, providing new and better methods and techniques, and proposal of new technology.

Civil Engineering

  • Erosion Control
  • Permitting
  • Roadway Design
  • Site Development
  • Site Plans
  • Site Survey (Sub-Contract Partner)
  • Soil Retention Structures
  • Soils/Drainage/Grading
  • Specifications

Extra High Voltage (500kV Substation) Experience

  • Last five years over 50-500kV substation projects
  • Includes 9 PCB, 9 MOD, and 10 transformer bank replacement projects
  • Includes addition of new 500 kV Bay
  • Replacement of 500 kV relaying at 2 stations

Physical (Outdoor) Design

  • Our Physical Design Group develops the following types of engineering documents:
  • Electrical Equipment General Arrangements for the Switchyards and Substations
  • Site Grading and Drainage
  • Structures/Foundations
  • Oil Containment Design
  • Equipment Plans, Elevations, and Sections
  • Control House Layout
  • Grounding Studies & Soil Resistivity Analysis
  • Conduit/Grounding Drawings
  • Bills of Material
  • Cable Schedules

Protection Schemes (Commonly Used)

  • Bank Differential
  • Breaker Failure Protection
  • Bus Differential
  • Capacitor Bank Protection
  • Distance Protection
  • Line Differential
  • Over-current protection
  • Over/Under Voltage protection
  • Over/Under frequency and load-shedding protection
  • Pilot Relaying Protection

Protection & Control (Indoor) Design

Our P&C Design Group develops the following types of engineering documents:

  • Single Line Diagrams
  • Three Line Diagrams
  • Panel Front Views
  • Elementary Diagrams (AC & DC)
  • Equipment & Switchboard Wiring Diagrams
  • Nameplates and Wiring Tags
  • Isolation & Restoration Work Plans
  • Detailed Work Descriptions
  • Battery Studies
  • Bills of Materials

Telecommunication Design

Our Telecommunication Design Group is responsible for communications between Substations/ Switchyards, including:

  • Digital Microwave Radio
  • Power Line Carrier Relaying
  • Fiber Optic Transport Systems
  • GPS Radio
  • Spread Spectrum Radio
  • Cellular Phone – Radio Frequency Electromagnetic Field Measurement
  • Wide Area Ethernet
  • Battery & Charger Systems
  • High Voltage Protection for Telephone Lines
  • Telemetering
  • Telephone Systems
  • Bills of Materials

Our Telecommunication Design Group develops the following types of engineering documents:

  • Single Line
  • Connection Diagrams
  • Jumper & Cable Diagrams
  • Line-to-set Connection Diagrams
  • Panel Arrangement
  • Bill of Material
  • Cable Schedules/Indices

Relay Settings & Programming

SEL Relays:



ABB Relays:



Areva Relays (formerly GEC):



GE Relays:


Relays Settings & Programming Steps:

  1. Gather Documents and Data
  2. Verify Model and Fault levels
  3. Revise MathCAD template
  4. Finalize preliminary settings through the relay setting curves in the model software
  5. Build relay settings files from final calculated settings and desired logic.
  6. Independent check and review of all assumptions, calculations and settings.

Oil Containment Experience

Phase 1 Study:

  • Station Evaluation
  • Spill Prevention Control & Countermeasure (SPCC) Plan

Phase 2 Detailed Design:

  • Containment & Diversionary Structures
  • Storage


Phase 3 Implementation

  • Remediation
  • Construction
  • Construction Management
  • Procedures
  • Inspection
  • Maintenance
  • Operation
  • Training

Transmission & Distribution

  • Experienced in Transmission-to-transmission Design
  • Experienced in Transmission-to-distribution Design
  • Extensive Station Distribution Experience

System Planning, Studies & Analysis

  • Load Flow Analysis
  • Short Circuit Analysis
  • Load Growth Projections
  • Economic Best Practices
  • Grounding Analysis
  • Software Experience
  • Etap, Milsoft’s Light Table & Windmill, Aspen, CAPE, CDEGS, and WinIGS

SCADA Design & Programming

Mesa is experienced with the following RTUs:

  • SEL-3530, SEL-2440, SEL-2411, SEL Axion RTAC,
  • Cooper SG4250
  • DAQ
  • Dymec Star
  • GE D-20 and GE D-20MX
  • Landis & Gyr
  • Integration with relays, breakers, metering, other SCADA systems


Electrical Panel Fabrication

  • Relay Panel Fabrication
  • SCADA Panels Fabrication
  • Instrument Tag Engineering Service
  • Complete Documentation
  • Installation/Start-up Assistance
  • Procurement Services


Substation & Switchyards Experience

  • Over 230 Professional, Technical, and Administrative Employees
  • 49 Registered Professional Engineers working in Power Delivery Substation
  • Over 2000 years of substation and switchyard experience


2000 years can be broken down as follows:

  • 40 years of TPS Planning Experience
  • 1700 years of Design Experience
  • 175 years of Communications
  • 90 years of Field Testing and Construction
  • Completed over 7,500 substation design projects over the last 10 years.


Types of Projects

  • Breaker Replacement
  • Line Relay Replacement
  • “Greenfield” Station
  • Transformer Bank Replacement/Addition
  • Metering Upgrades
  • Capacitor Bank
  • Reactor Bank