NABCEP PVCMS case studies
NABCEP PVCMS · Put your knowledge to work in context.
The NABCEP PV Commissioning & Maintenance Specialist (PVCMS) is a board certification for photovoltaic professionals who make decisions about the operations, commissioning and maintenance of PV systems. NABCEP describes PVCMS Specialists as combining the skill sets of operations, maintenance and commissioning tasks into one job specialty, and states that exceptional application of verification protocols and preventive and corrective maintenance operations is key to this Board Certification. The NABCEP PVCMS case studies are 5 cases and about 2,682 words.
1Performance Guarantee Dispute After Irradiance Drift
Your firm operates a 1.62 MWDC / 1.25 MWAC community solar array under a five-year O&M agreement. The contract guarantees a weather-adjusted performance ratio (PR) of 80.0%, measured monthly using the site's secondary-standard pyranometer and a reference cell.
620 words, about 3 min2Staircase I-V Curve at Commissioning Sign-Off
During commissioning of a 486 kWDC rooftop system, you are reviewing field test results before the utility witness test. The array has three 125 kW string inverters, each with 12 strings of 13 bifacial 450 W modules at 25° tilt and 180° azimuth.
547 words, about 3 min3Rain-Triggered Isolation Fault at a Public Carport
A 208 kWDC carport array at a municipal fleet yard has tripped on inverter 'isolation fault' three times in six weeks, each time within 24 hours of rain. The inverter is a 100 kW three-phase string unit with integrated GFDI and a 0.5 A residual current monitor.
527 words, about 3 min4Soiling Wash Decision at a Tracker Site
At a 4.9 MWDC single-axis tracker site in a semi-arid region, monthly performance reports show PR falling from 82.1% in March to 77.9% in June. The site has a soiling station, but its glass coupon was installed 18 months ago and is cleaned quarterly on the same schedule as the arrays.
478 words, about 2 min5Re-Commissioning After Hail Damage and Inverter Replacement
Following a hailstorm, a 740 kWDC commercial rooftop array lost 38 modules on two strings, and one 60 kW inverter was replaced under warranty. The EPC's crew installed same-model replacement modules and re-terminated 14 MC4 pairs, then re-landed the DC feeders at the new inverter and updated the string plan.
510 words, about 3 min