Articles 625, 690, 705, 706.
3
hours
0.3
CEUs
Codes and Standards
1.7.3
This course covers material relevant to the following ICC certification exams:
Articles 625, 690, 705, 706.
Format
On-Demand Online
Delivery
Self-Paced
Access
24/7 After Enrollment
Certification
Certificate of Completion
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Contact our support teamUnderstand the electrical characteristics that make a photovoltaic array a distinct hazard
A photovoltaic array is unlike almost any other source in the electrical code: as long as light reaches the modules, the array produces power, whether or not anyone wants it to. There is no equivalent of opening a main breaker to render the whole system safe. That single fact — the source itself cannot be switched off — is why solar PV earns its own dedicated body of requirements.
Every PV installation is really two systems joined at an inverter. The array and its home-run conductors carry direct current, a steady one-directional flow; past the inverter, the output behaves like ordinary alternating current feeding a panel. The distinction matters because DC faults do not self-interrupt the way AC faults do — an arc can sustain itself, since DC current never crosses through zero the way AC does many times each second. That is why DC-side conductors, connectors, and disconnects carry their own design, listing, and arc-flash-aware requirements.
Picture a reviewer opening a submittal for a rooftop array on an existing building. Before evaluating any single detail, the first task is tracing the one-line diagram and separating it conceptually into its DC and AC halves — locating exactly where the array output stops behaving like a DC source and starts behaving like an ordinary AC source at the inverter. Only then does evaluating disconnects, labeling, and conductor protection make sense, since each applies differently on either side of that line.
The most persistent error is applying ordinary-circuit thinking to the DC side — assuming a downstream disconnect, such as at the inverter, leaves every upstream conductor de-energized the way a service disconnect would. It does not: the array keeps producing voltage on its own conductors as long as light reaches the modules. A related mistake is treating DC connectors as interchangeable with AC branch-circuit components, when DC arcing behaves differently. The correction: evaluate every DC-side component against DC-specific requirements, and never assume a downstream disconnect renders upstream array conductors safe.
Code Reference: NEC Articles 625, 690, 705, 706 - The code establishes minimum requirements for solar pv system design to ensure public health, safety, and welfare. Requirements vary based on occupancy classification, construction type, and building height and area.
Apply load-calculation principles to electric-vehicle charging installations
Electric-vehicle charging equipment behaves differently from almost any load a building's electrical system typically sees: a vehicle plugged in to charge draws power steadily over an extended stretch, rather than cycling on and off the way ordinary loads do. Spare capacity that comfortably absorbs intermittent plug loads cannot be assumed to absorb a charging load the same way, since a sustained, near-maximum draw places a different demand on conductors, overcurrent protection, and the service itself. Recognizing charging equipment as a continuous load is the starting judgment behind this module.
Charging equipment is generally grouped into recognizable tiers: a slow tier for unattended overnight charging from an ordinary outlet-style connection, a faster dedicated-circuit tier common to homes and workplaces, and a high-power tier — reserved mainly for commercial and public settings — that delivers direct current straight to the vehicle rather than relying on its onboard charger. Because charging equipment is so often installed outdoors or in publicly accessible locations, it relies on dedicated ground-fault personnel protection, the same protective concept behind GFCI protection elsewhere in the code. And because a building may host several stations at once, an energy-management approach that actively coordinates each station's draw is a recognized alternative to sizing service for every station's full simultaneous draw.
Consider an owner adding several charging stations to an existing parking structure never designed with vehicle charging in mind. The reviewer's job is not just confirming each station is wired correctly in isolation, but confirming the added continuous load was actually folded into a fresh look at service capacity — not assumed to fit existing headroom. Where the design proposes managing load actively across stations rather than sizing for the full simultaneous total, the reviewer verifies that method is documented, not informal.
A common failure is treating an added station like a minor receptacle addition, without re-examining whether the service was ever sized for a sustained, near-maximum draw. A related failure is proposing energy management to justify a smaller service without documenting how it actually limits the load, and personnel protection is sometimes skipped on the assumption a charging station is no different from an ordinary receptacle. The correction: treat every charging addition as a load-calculation question first, verify the continuous-load impact, substantiate any management claim, and address personnel protection on its own terms.
Code Reference: NEC Articles 625, 690, 705, 706 - The code establishes minimum requirements for ev charging station installation to ensure public health, safety, and welfare. Requirements vary based on occupancy classification, construction type, and building height and area.
Understand the fire-safety principles that govern energy storage system installations
A battery energy storage system introduces a hazard fundamentally different from an ordinary electrical fire. An electrical fire is typically driven by something external to the current path — a loose connection overheating, insulation failing. A battery in thermal runaway is different: once a cell fails internally, the failure generates heat faster than it can be carried away, driving further failure in neighboring cells in a self-sustaining, escalating chain that needs no external ignition source to keep going. That distinction is why energy storage systems receive their own dedicated body of requirements.
Because a runaway event can release flammable or hazardous gases as it progresses, where a storage system sits and how it is ventilated is not an ordinary clearance question — it is a question of managing where those gases go and how far a failure can propagate before reaching occupied space or combustible material, and separation from living or working space follows the same logic. Disconnects carry their own wrinkle: unlike an ordinary appliance, a battery does not stop being a hazard once isolated from the building's circuits, because the stored chemical energy inside it does not disappear when the electrical connection opens.
Imagine an inspector examining a battery unit added to the mechanical room of an existing building. Rather than checking it against a generic equipment checklist, the inspector works through questions specific to stored chemical energy: is the unit sited and separated to limit how a failure could propagate toward occupied space, is ventilation suited to what that battery chemistry could release, and is there a clear means to disconnect the unit from both its load and its charging source.
A frequent mistake is evaluating a storage installation with the same clearance thinking applied to ordinary equipment, without separately asking how a thermal-runaway event specific to that chemistry would actually propagate. Ventilation is sometimes treated as a generic mechanical requirement rather than one tied to the gases a given technology could release under failure, and disconnects are occasionally provided only on the charging side, leaving no clear way to isolate the battery from its load. The correction: evaluate location, ventilation, and disconnects against the specific failure behavior of the installed chemistry, not a generic equipment standard.
Code Reference: NEC Articles 625, 690, 705, 706 - The code establishes minimum requirements for energy storage system integration to ensure public health, safety, and welfare. Requirements vary based on occupancy classification, construction type, and building height and area.
Apply rapid-shutdown, grounding, and interconnection safety requirements for PV systems
Module one established that a PV array cannot simply be switched off like a utility service. Rapid shutdown answers the safety problem that creates: responders working on or near a roof carrying live PV conductors need a defined, reliable way to bring those conductors to a low-hazard condition quickly, without tracing the array's wiring under emergency conditions. The concept only works if people can find it — which is why standardized labeling at the building exterior and at every disconnect is treated as inseparable from the rapid-shutdown function itself. A rapid-shutdown system nobody can locate provides little practical benefit over having none.
An array is also a large, distributed metallic structure spread across a roof rather than one contained enclosure, which is why grounding and bonding the framework back to the building's grounding system is its own dedicated concern. Interconnection is a related but separate concept: once the inverter output joins the building's electrical system, it is effectively backfeeding power onto that system alongside the utility, and the connection has to be engineered against what the existing distribution equipment can safely carry. The same interconnection must reliably separate the PV system from the utility whenever utility power is lost, so a de-energized line is never endangered by continued backfeed.
During a field inspection of a completed rooftop PV installation, the inspector confirms a permanent label is actually present at the service equipment and correctly identifies where the rapid-shutdown initiation point is located — not simply that a rapid-shutdown feature exists somewhere. The inspector then verifies the array's metallic framework is bonded back to the building's grounding system at every required point, and confirms the point where the inverter joins the building's system was engineered, not simply spliced in wherever was convenient.
The most consequential field deficiency here is a rapid-shutdown label that is missing, illegible, or does not match where the initiation device is located — a defect that looks minor but undermines responder safety. A related failure is grounding and bonding treated as an afterthought, with sections of the frame left unbonded; on the interconnection side, the recurring error is a connection point chosen for construction convenience rather than engineered against existing equipment capacity. The correction: verify labeling matches the field, confirm bonding continuity across the array, and confirm the interconnection was calculated, not assumed.
Code Reference: NEC Articles 625, 690, 705, 706 - The code establishes minimum requirements for solar pv system design to ensure public health, safety, and welfare. Requirements vary based on occupancy classification, construction type, and building height and area.
Verify EV charging, PV, and storage installations during plan review and field inspection, especially in existing buildings
Solar PV, EV charging, and energy storage are frequently added to buildings never originally designed around them, which sets this course apart from a typical new-construction review. New construction lets a designer plan service capacity and interconnection from a blank sheet; a retrofit forces a reviewer to treat the existing electrical system as a fixed constraint the addition has to fit within, or as something that itself needs upgrading. That distinction is easy to lose sight of when a proposed addition looks straightforward on paper, which is exactly why it deserves deliberate attention.
Across all three systems the same philosophy recurs: know where the isolation points are, and make sure anyone who might need them — a responder, a maintenance worker, an inspector returning years later — can find and understand them without guesswork. Plan review tests that philosophy on paper: the design's impact on existing service capacity, whether interconnection was engineered rather than assumed, and whether rapid-shutdown, disconnects, and grounding were treated as designed requirements, not afterthoughts. Field inspection tests the same philosophy against reality: labeling present and accurate, disconnects functional and reachable, rapid-shutdown initiation doing what its label claims.
Consider a reviewer evaluating a battery storage system proposed for the mechanical room of an older multi-family building that also recently added rooftop PV. On paper, the addition looks like a simple equipment swap. Working through the retrofit questions first, the reviewer notices what the submittal glossed over: the service was never re-evaluated after the earlier PV interconnection, and the labeling package does not clearly show how a responder would isolate either system independently. Because the review caught both gaps on paper, the design goes back for correction before installation, rather than surfacing as a hazard in an emergency.
Across all three systems the same failures recur: a service never re-sized for an added continuous EV load; a backfeed path connected without engineering it against existing equipment capacity; a storage system sited or ventilated without regard to its failure behavior; grounding treated as incidental rather than verified at every connection; and rapid-shutdown or disconnect labeling that is missing or does not match what was installed. Each is far cheaper to catch on paper than in the field. The correction: verify existing capacity was actually reassessed, and verify every isolation point is labeled, functional, and reachable.
Code Reference: NEC Articles 625, 690, 705, 706 - The code establishes minimum requirements for ev charging station installation to ensure public health, safety, and welfare. Requirements vary based on occupancy classification, construction type, and building height and area.
This course examines how photovoltaic systems, electric-vehicle charging equipment, and battery energy storage systems are treated as a distinct category of installation under the National Electrical Code. Each introduces a hazard ordinary branch-circuit rules were never designed around: an array that cannot be switched off at will, a charging load sized for sustained rather than intermittent draw, and stored chemical energy capable of a self-sustaining thermal failure. Because these systems are so often added to buildings not originally designed around them, the course also emphasizes the retrofit lens — verifying that existing service capacity, interconnection, grounding, and disconnect labeling were actually reassessed, not assumed.