Industry · solar and battery storage
Solar arc flash study that treats AC and DC hazards the right way
US arc flash studies, PE-reviewed, quoted in 24 hours. Ready before commercial operation, not after.
- PE-reviewed
- Built on current NFPA 70E-2027
- IEEE 1584-2018
- Field engineers travel to every US state
- Written quote in 24 hours
A solar arc flash study calculates incident energy on both sides of the inverter: the DC array, combiners and battery racks, and the AC collection system, transformers and switchgear. IEEE 1584-2018 covers only three-phase AC, so AFSC applies the DC methods NFPA 70E-2027 references to the DC side and states each method in the report.
Why now
The deadlines that drive a solar or storage study
Commissioning and COD
Labels and PPE rules should be in place before the plant is energized and the operations team takes over.
Battery storage added to a PV site
A new BESS adds DC sources and changes AC fault levels at the point of interconnection.
Owner or lender requirements
Owners, lenders and their engineers can ask for a documented study before handover or refinancing.
Hazards and governing standards for PV and storage
| Reference | Scope |
|---|---|
| NFPA 70E-2027 | Arc flash risk assessment, labels and PPE, including DC methods in Annex D and DC PPE categories |
| IEEE 1584-2018 | Three-phase AC incident energy only |
| NEC (NFPA 70) Articles 690 and 691 | Photovoltaic systems and large-scale PV plants |
| NEC (NFPA 70) Articles 480 and 706 | Batteries and energy storage systems |
| NFPA 855 | Installation of stationary energy storage systems |
IEEE 1584-2018 model range, and why DC falls outside it
IEEE 1584-2018 was built from three-phase AC test data. Inside the ranges below, its incident energy model applies. Outside them, including any DC system, a different method is needed.
| Parameter | Range covered |
|---|---|
| System type | Three-phase AC at 50 or 60 Hz |
| Voltage | 208 V to 15 kV |
| Bolted fault current | 500 A to 106 kA (208 V to 600 V); 200 A to 65 kA (601 V to 15 kV) |
| Conductor gap | 6.35 mm to 76.2 mm (208 V to 600 V); 19.05 mm to 254 mm (601 V to 15 kV) |
| Working distance | 305 mm (12 in) or more |
| DC systems | Not covered |
Commercial operation date set? Label before energization.
Send the single-line diagram and your COD. A fixed price and a plan that fits commissioning come back within one business day.
Typical scope at a solar or storage site
| Equipment | Method and output |
|---|---|
| PV strings and combiners | DC method, incident energy in cal/cm², labels on each combiner |
| Inverters | DC input and AC output assessed separately |
| BESS racks and containers | DC method with battery data from the manufacturer |
| Collector system and transformers | IEEE 1584-2018 up to 15 kV; other methods above it |
| Point of interconnection | Utility fault data and the main breaker |
What a typical project looks like
Illustrative scenario, no client named and no figures claimed: a solar plant adding battery storage needs labels before the new system is energized. Engineers model the existing array and the new racks together, gather battery fault data from the manufacturer, and install DC and AC labels during commissioning, before the operations team takes over.
BESS arc flash study, where the battery sets the numbers
A BESS arc flash study depends on the battery's own fault current and how fast the protection clears it, which only the manufacturer's data can provide. DC arcs do not pass through current zero the way AC arcs do, so they can be harder to interrupt. We model each rack and container and label DC and AC sides separately.
DC arc flash study methods, explained
A DC arc flash study uses methods referenced in NFPA 70E-2027 Annex D, such as the maximum power method, because IEEE 1584-2018 does not cover DC. These methods tend to be conservative, which can push PPE higher than needed. We state the method used for every DC result and flag where better data would safely lower it.
Frequently asked questions
Question not here? Ask an engineer
Do solar farms and battery storage sites need an arc flash study?
Yes. Solar farms and battery storage sites have energized DC and AC equipment that technicians service, so NFPA 70E-2027 requires an arc flash risk assessment and labels. Utility-owned plants may fall under OSHA 29 CFR 1910.269 instead, but either way the incident energy must be estimated and documented before crews work on live equipment.
Does IEEE 1584-2018 apply to DC systems like solar and battery storage?
No. IEEE 1584-2018 covers three-phase AC systems from 208 V to 15 kV only. The DC side of a solar or storage site, including strings, combiners and battery racks, needs DC methods such as those in NFPA 70E-2027 Annex D. The AC collection system and transformers can still use IEEE 1584-2018.
Which method do you use for the AC collection system above 15 kV?
Collector systems often run above the IEEE 1584-2018 range, so those buses use other recognized methods for higher voltages. We state the method for each bus in the report, and keep the PE review consistent across DC, low voltage AC and medium voltage AC results.
What data do you need from the battery manufacturer?
We need the battery's short-circuit current, internal resistance and the clearing characteristics of the DC protection, from the manufacturer's datasheets or test reports. If the data is incomplete, we use conservative assumptions, flag them in the report and show how better data would change the result.
Can labels go on before commercial operation?
Yes, and that is the right time. We model from the design single-line and equipment data, verify the installed equipment during commissioning, and install labels before energization. The operations team then takes over a site where every panel already shows its hazard.
How fast can we get a price?
Within 24 hours. Send the single-line diagram, inverter and battery models, and your commissioning schedule, and an engineer returns a fixed written price with a dated plan that fits your path to commercial operation. We price from those documents alone, with no trip to the array.
Get your arc flash study quoted
Tell us about your facility. An engineer replies within one business day with scope, timeline and price.
- IEEE 1584-2018 and NFPA 70E-2027, PE-reviewed
- Labels and training in the same scope
- Field engineers travel to any US state