Solar power plants form a chain starting with 1000 V or 1500 V DC arrays and connected to the grid via inverters, transformers, and medium-voltage switchgear. In rooftop solar power plants, this chain is connected to existing plant panels. The arc flash study treats the AC and DC sections of this chain separately.

Sections evaluated in GES

• Medium voltage switchgear and power plant transformers
• AC output of inverters and AC collection panels.
• Connection point to the main distribution panel of the facility in rooftop solar power systems.
• DC string boxes and DC inputs of inverters
• Battery storage system, if any.

Calculation approach

IEEE 1584-2018 defines incident energy calculation for three-phase AC systems at voltages between 208 V and 15 kV and frequencies of 50/60 Hz. Single-phase and DC systems are not included in the model; the standard only refers to methods in the literature (Ammerman, Das, Doan, Klement) for DC (clauses 4.11 and 4.12). The AC components of the solar power plant are calculated within this scope; the fault current contribution of the inverters is modeled using manufacturer data.

DC sections (battery banks, DC side of inverters, PV arrays, DC distribution) are not calculated using IEEE 1584. In these sections, incident energy is calculated separately using DC methods from the literature and reported separately from AC results; the method and assumptions used are clearly stated in the report. In PV arrays, the short-circuit current is radiation-dependent and close to the operating current; therefore, the protection device on the DC side may not clear the fault quickly, and this is taken into account in the calculation.

Data requested in the GES study

• AC and DC single-line diagram
• Panel, array, and summing box structure (number of panels per array, number of parallel arrays)
• Inverter brand, model, and fault current data.
• Transformer and MV switchgear data, grid short-circuit power at the connection point.
• Types and values of DC and AC protection elements.

For solar power plant inspection and photovoltaic installation requirements. Photovoltaic (GES) system inspection You can check out our page.

Reducing incident energy

The calculation results are used not only for selecting PPE but also for reducing risk at its source. The report provides panel-specific recommendations; commonly applied methods include:

• Reconfiguring protection settings to take incident energy into account.
• Fast-trip (maintenance mode) settings enabled during maintenance.
• Arc detection relays (light and current sensing)
• Remote switching and remote racking of withdrawable breakers.
• Isolator and quick-shutoff systems in DC collection boxes

De-energized work always comes first; energized work is permitted only when justified and under an energized electrical work permit.

The scope of AES Innovation

We conduct arc flash analysis end-to-end, including data collection, modeling, incident energy calculation, reporting, and labeling. Reports can be prepared in Turkish, English, or bilingually. For general process and pricing factors, please contact us. arc flash analysis and labeling You can check out our page.

Frequently Asked Questions

Will there be arc flash on the DC side of the GES?

Yes. Arcs can occur in 1000 V and 1500 V DC arrays, and the DC arc may not extinguish spontaneously; the DC sections are evaluated using a separate method.

Will a rooftop solar power system affect my current arc flash study?

It could have an impact. Since connecting a solar power plant can alter the facility's short-circuit currents and protection system, the existing work may need to be updated.

How is the inverter contribution taken into account?

The inverter is modeled using the manufacturer's fault current data; if data is unavailable, this is stated as accepted in the report.