Substation Engineer

Ryan Mahoney

Why this role is hard · Ryan Mahoney

Finding a solid junior substation engineer is tough because the role demands sharp technical judgment before they have years of field experience. We look for people who can read single line diagrams without guessing, select standard breakers from approved lists, and walk field crews through voltage drop calculations in plain terms. The real test comes during a mock layout review where cable clearances bump into existing conduit, separating those who actually understand spatial constraints from those who just memorized textbook protection math. We hire for steady hands and quiet confidence rather than flashy software certifications or rehearsed interview answers. A strong candidate will openly admit what they do not know and ask for the regional design manual instead of guessing through a clearance check.

Core Evaluation

Critical questions for this role

The competency and attitude questions below are where the hiring decision is made. They run in the live interview rounds and are calibrated to the level selected above.

17 Competency Questions

1 of 17
  1. Discipline

    Control Systems, Compliance & Strategic Operations

  2. Job requirement

    Industrial Automation & SCADA Integration

    Configures basic HMI screens, maps data points, and troubleshoots communication faults.

  3. Expected at Junior

    Focuses on foundational point mapping and basic screen configuration; proficiency 2 ensures reliable execution of standardized automation tasks with guidance.

Interview round: Hiring Manager Technical - Core Engineering & Design

Walk me through how you mapped data points or configured basic HMI screens for a substation monitoring system.

Positive indicators

  • Follows point list templates strictly
  • Cross-references tags accurately
  • Applies operator interface standards
  • Verifies communication links before submission

Negative indicators

  • Maps points from memory without templates
  • Ignores established tagging standards
  • Configures screens without interface guidelines
  • Skips communication verification

14 Attitude Questions

1 of 14

Active Listening

The disciplined practice of fully concentrating on, comprehending, and thoughtfully responding to verbal and non-verbal communication from technical teams, field personnel, regulators, and stakeholders. For a Substation Engineer, it involves synthesizing disparate operational insights, safety observations, and cross-functional requirements to inform system design, mitigate risk, and ensure seamless project execution without prematurely imposing theoretical assumptions.

Interview round: Recruiter Screen - Role & Culture Fit

How would you approach a design review meeting where multiple stakeholders provide overlapping feedback on your single-line diagram?

Positive indicators

  • Proposes a structured capture method for multi-voice input
  • Identifies need to resolve conflicts before drafting
  • Validates understanding through real-time paraphrasing

Negative indicators

  • Attempts to address all feedback simultaneously without filtering
  • Assumes priority without consulting project leads
  • Leaves conflicting notes unresolved in the deliverable

Supporting Evaluation

How candidates earn the selection conversation

The goal is to reduce effort for everyone by collecting more useful signal before adding more interviews. Lightweight application prompts and structured screens help the panel focus live time on the candidates most likely to succeed.

Stage 1 · Application

Filter at the door

Runs the moment a candidate hits Submit. Disqualifying answers end the application; everything else is captured for review.

Video-Response Questions

1 of 2

Application Screen: Video Response

Describe a situation where a contractor or field technician flagged a practical installation constraint that conflicted with your preliminary design. Walk me through how you communicated your decision to either modify the design or maintain the original specification, ensuring their operational concerns were addressed.

Candidate experience

REC
0:42 / 2:00
1Record
2Review
3Submit

Response time

2 min

Format

Recorded video

Stage 2 · Resume Screening

Read the resume against fixed criteria

Reviewers score every application that clears the door against the same criteria. Stronger reviews advance to live interviews; weaker ones are archived without further screening.

Resume Review Criteria

8 criteria
Demonstrates ability to perform power system calculations and model electrical behavior using industry-standard simulation tools.
Produces electrical schematics, grounding layouts, or equipment arrangement drawings that align with established transit or utility standards.
Participates in multidisciplinary engineering workflows, aligning electrical deliverables with civil, mechanical, or SCADA teams.
Develops or executes verification protocols for electrical equipment prior to energization.

Is the resume complete, well-organized, and free from formatting, spelling, and grammar mistakes?

Does the resume show relevant prior work experience?

Does the cover letter or personal statement convey clear relevance and familiarity with the job?

Does the resume indicate required academic credentials, relevant certifications, or necessary training?

Stage 3 · During Interviews

Where the hire is decided

Interview rounds use the competency and attitude questions outlined above, then add tests, work simulations, and presentations that reveal deeper evidence about how the candidate thinks and works.

Presentation Prompt

Walk us through your approach to designing a high-voltage equipment layout for a constrained urban substation pad where civil grading limits footprint options and maintenance crews require strict clearance zones. Slides are optional; you may talk through your reasoning step-by-step.

Format

approach-walkthrough · 20 min · ~2 hr prep

Audience

Hiring manager, lead protection engineer, and civil/site coordinator

What to prepare

  • Review your past experience with urban pad layouts or similar spatially constrained high-voltage designs
  • Prepare to discuss your mental model for balancing electrical code clearances, grounding grid requirements, and physical access needs

Deliverables

  • A verbal walkthrough of your design reasoning
  • Optional 2-3 reference sketches or past layout excerpts (redacted as needed)

Ground rules

  • Use only work you are permitted to share
  • No need to produce new drawings during the session
  • Focus on your decision-making process and tradeoff evaluation

Scoring anchors

Exceeds
Proactively identifies hidden constraints, proposes multiple viable layout strategies with clear tradeoff analysis, and demonstrates strong safety/maintenance foresight.
Meets
Walks through a logical layout process, addresses key clearance and access constraints, and shows baseline understanding of code compliance and cross-trade coordination.
Below
Proposes a generic layout without considering site constraints, struggles to explain safety clearances, or cannot articulate how they would resolve spatial conflicts.

Response time

20 min

Positive indicators

  • Surfaces assumptions about soil, clearance, and maintenance access early
  • Asks high-information clarifying questions about site constraints before proposing a layout
  • Explains how they would validate design choices against safety codes and constructability feedback
  • Demonstrates awareness of how layout impacts future maintenance and safety compliance

Negative indicators

  • Jumps straight to a standard template without addressing site-specific constraints
  • Ignores civil grading or maintenance access tradeoffs
  • Fails to articulate how they would handle conflicting clearance requirements
  • Relies heavily on jargon without explaining the underlying engineering rationale

Work Simulation Scenario

Scenario. You are assigned to perform short-circuit fault level calculations for a new urban substation pad. The project manager has provided a preliminary single-line diagram, but the existing utility grid data is outdated, and civil constraints limit the pad footprint, potentially affecting grounding and switchgear selection.

Problem to solve. Determine the approach to complete accurate fault calculations, identify missing data, and propose a switchgear rating baseline that accounts for both electrical safety and spatial constraints.

Format

discovery-interview · 40 min · ~2 hr prep

Success criteria

  • Surfaces critical missing data points before starting calculations
  • Articulates assumptions and validation steps clearly
  • Balances safety margins with physical site constraints

What to review beforehand

  • Basic IEC 60909 fault calculation methodology
  • Switchgear rated duty considerations
  • Urban substation spatial constraint tradeoffs

Ground rules

  • Ask clarifying questions to gather necessary context
  • Think out loud about your analytical process
  • You are not expected to produce final calculations, but to define your approach

Roles in scenario

Utility Data Coordinator (informed_partner, played by hiring_manager)

Motivation. Ensure the engineering team does not over-spec equipment due to conservative guesses, while maintaining grid safety.

Constraints

  • Historical grid impedance data is 5 years old
  • Utility cannot provide a new study for 3 weeks due to backlog
  • Project timeline requires preliminary switchgear ordering in 10 days

Tensions to introduce

  • Push back on requests for data that isn't available yet
  • Provide honest answers if asked about typical fault current ranges for similar substations
  • Mention that the utility recently upgraded a nearby transformer but hasn't updated the public database

In-character guidance

  • Answer questions directly and factually
  • Do not volunteer information unless explicitly asked
  • Acknowledge the candidate's technical reasoning if sound

Do not

  • Do not solve the fault calculation for the candidate
  • Do not steer them toward a specific software or methodology
  • Do not withhold standard industry data if they ask the right clarifying question

Scoring anchors

Exceeds
Systematically maps data gaps, proposes validated interim assumptions, and clearly communicates how spatial constraints will impact grounding and equipment selection while maintaining safety margins.
Meets
Identifies key missing data, asks relevant clarifying questions, and outlines a reasonable calculation approach with basic assumptions.
Below
Jumps to conclusions without asking for system parameters, guesses values arbitrarily, or fails to address the timeline and spatial constraints.

Response time

40 min

Positive indicators

  • Asks high-information questions about grid topology, transformer impedance, and fault contribution sources
  • Explicitly states assumptions and how they will be validated
  • Proposes a pragmatic interim approach given timeline constraints

Negative indicators

  • Guesses fault current values without asking for system data or assumptions
  • Freezes when faced with missing utility data instead of structuring an information-gathering plan
  • Ignores spatial constraints when discussing switchgear selection

Progression Framework

This table shows how competencies evolve across experience levels. Each cell shows competency at that level.

Control Systems, Compliance & Strategic Operations

4 competencies

CompetencyJuniorMidSeniorPrincipal
Industrial Automation & SCADA Integration

Configures basic HMI screens, maps data points, and troubleshoots communication faults.

Integrates multi-vendor RTU/PLC networks, optimizes polling architectures, and implements cybersecurity baselines.

Designs enterprise SCADA architecture, integrates data historians, and leads automation upgrade programs.

Drives IIoT/edge computing adoption, autonomous grid control frameworks, and enterprise digital transformation strategies.

Safety, Regulatory Compliance & Risk Management

Applies compliance checklists, documents safety observations, and participates in incident reviews.

Conducts HAZOP/FMEA analyses, leads regulatory audits, and develops site-specific safety protocols.

Develops corporate compliance frameworks, manages regulatory reporting, and oversees enterprise risk mitigation programs.

Shapes corporate risk strategy, influences industry regulatory standards, and establishes sustainability and resilience compliance mandates.

Strategic Asset Lifecycle & Fleet Electrification Planning

Tracks asset inventory, supports budget forecasting, and assists with electrification feasibility studies.

Develops lifecycle cost models, creates electrification roadmaps, and evaluates technology adoption trade-offs.

Aligns capital planning with operational goals, manages vendor portfolios, and oversees multi-year infrastructure scaling.

Sets enterprise electrification strategy, drives sustainable infrastructure investment frameworks, and leads cross-agency policy alignment.

Testing, Commissioning & Maintenance Protocols

Executes standardized test procedures, records results, and documents punch-list items.

Develops comprehensive commissioning plans, troubleshoots complex system failures, and optimizes test sequences.

Manages commissioning across multiple sites, standardizes maintenance strategies, and coordinates with operations teams.

Establishes enterprise testing standards, implements AI-driven predictive maintenance programs, and drives reliability-centered maintenance frameworks.

Power Systems & Substation Design

4 competencies

CompetencyJuniorMidSeniorPrincipal
High-Voltage Equipment & Layout Design

Drafts equipment layouts and single-line diagrams under supervision using established standards.

Independently optimizes spatial arrangements and equipment specifications to balance fault clearance, maintenance access, and cost.

Leads cross-functional design reviews and resolves complex spatial or equipment compatibility conflicts across multiple projects.

Defines enterprise layout standards, evaluates next-generation HV equipment, and drives innovation in compact and modular substation design.

Power System Analysis & Load Flow Modeling

Runs basic load flow and short-circuit models using predefined templates.

Conducts complex stability, harmonic, and arc-flash analyses to validate design margins.

Validates simulation models against field telemetry and leads system expansion studies.

Develops advanced modeling methodologies, grid resilience frameworks, and predictive capacity planning tools.

Protection & Control Systems Engineering

Sets relay parameters, drafts protection coordination curves, and documents control logic under senior guidance.

Designs complex protection coordination schemes and implements IEC 61850 communication architectures.

Oversees protection system integration, cybersecurity hardening, and cross-vendor interoperability testing.

Architects next-generation digital substation protection, adaptive control strategies, and industry standard contributions.

Utility Interconnection & Grid Integration

Prepares interconnection applications, gathers utility data, and supports basic load impact studies.

Negotiates interconnection agreements, resolves technical constraints, and coordinates with utility engineers.

Coordinates multi-utility interconnection projects, manages grid impact studies, and aligns technical deliverables with regulatory timelines.

Defines strategic grid integration policies, leads large-scale DER hosting capacity studies, and shapes regional interconnection standards.