Solar O&M Prep

OMAT Operations and Maintenance: Tasks and Knowledge Items

21.7% of the OMAT exam

Operations and Maintenance is 21.7% of the exam across six tasks — the most tasks of any domain, and the only domain where the four content areas are performance, monitoring, test equipment and fault diagnosis rather than knowledge of components. Task 3 alone lists nine instruments. This is the part of the blueprint that is genuinely about the job title, and it is worth noticing that it is only about a fifth of the exam: candidates who study only this domain are studying a fifth of the test.

Task 1: Performance Parameters

  1. Local conditions (e.g., weather, soiling, temperature, windspeed, irradiance)
  2. Site conditions (e.g., shading, orientation, utility voltage and frequency)
  3. Equipment and performance (e.g., system losses, inverter compatibility, inverter voltage [AC and DC])
  4. IV curve characteristics (e.g., short circuit, open circuit, maximum power point [MPP])
  5. Battery voltage
  6. Battery state of charge (SOC)

Task 2: System Monitoring Equipment and Applications

  1. Monitoring methods (e.g., app- and web-based, on-site)
  2. Data acquisition and control (e.g., DAS, SCADA)
  3. Instrumentation transformers (e.g., current transformers [CT], potential transformer [PT])
  4. Revenue grade meter
  5. Weather monitoring systems (e.g., albedometer, pyranometer, anemometer, thermometer)
  6. Battery temperature sensors
  7. Amp hour meter

Task 3: Electrical Test Equipment and Application

  1. Multimeters (e.g., current, voltage, resistance, continuity)
  2. Insulation testing devices (e.g., megohmmeter)
  3. IV curve tracer
  4. Infrared thermometer
  5. Irradiance meter
  6. Battery capacity testing devices (e.g., load tester)
  7. Hydrometer
  8. Refractometer
  9. Thermal camera

Task 4: Deviations from Expected Performance

  1. Test conditions (e.g., Standard Test Conditions [STC], nominal operating cell temperature [NOCT])
  2. Installation deficiencies
  3. Electrical faults (e.g., arc fault, ground fault)
  4. Production losses and their causes (e.g., weather, pollution, shading, animals, soiling, system degradation)
  5. System curtailment (e.g., export limitation, load control)

Task 5: Maintenance of PV Systems

  1. Scopes of work (e.g., preventative and reactive maintenance, inspections, cleaning, vegetation management, remote monitoring)
  2. Record keeping (e.g., system logging, data sheets, user manuals, as-built plan set, maintenance plan, photography)
  3. Visual inspection
  4. Equipment replacement (e.g., installation practices, lockout/tagout, service life)
  5. Equipment-specific maintenance requirements (e.g., lockout/tagout, torque requirements, cleaning)

Task 6: System Commissioning

  1. Visual inspection (e.g., Quality Assurance Quality Control [QAQC], installation checklists)
  2. Testing (e.g., thermography, string voltage, polarity)
  3. Proper operation of equipment (e.g., inverter operation, monitoring/communication, disconnects)
  4. Documentation (e.g., commissioning forms, manufacturer checklists, photo checklists, permission to operate [PTO])