Field guide
Arc Flash Labels for Switchgear: 600 V Class and Up
Is a label required?
Yes. Switchgear is serviced energized as a matter of practice — racking, testing, metering — and it sits at the top of the incident-energy range, so the label question is not whether but how accurate. NEC 2026 §110.16 covers it as non-dwelling service or feeder equipment, and NFPA 70E §130.5(H) requires the field label after the assessment. If any equipment in the building deserves a careful calculation rather than a table lookup, it is the switchgear lineup.
What the label shows for this equipment
Switchgear labels show the same required fields — nominal voltage, incident energy, arc-flash boundary, PPE level, assessment date, available fault current with its as-of date, and a study or label ID — with two practical differences. Large lineups take 6×8 in labels where the reading distance is longer, and multi-section lineups need per-section values: the main section and the furthest feeder section do not share a clearing time, and sharing a label would be wrong. Electrode configuration is VCB or VCBB for most metal-clad construction.
NFPA 70E table-method rows for this class
| Equipment class row | Max fault current | Max clearing time | PPE category |
|---|---|---|---|
| 600 V class metal-clad switchgear | 35 kA | 0.50 s | 4 |
Rows come from NFPA 70E-2018 Table 130.7(C)(15)(a), cells cross-verified against multiple independent reproductions. If your fault current or clearing time exceeds the row, the table does not apply — an IEEE 1584-2018 calculation is the path, which is what the calculator runs.
Notes specific to this equipment
The verified 600 V switchgear table row assigns Category 4 only while every row condition is met; it does not estimate incident energy. For calculated switchgear, report the incident energy directly and select a system rated at least that value—do not map the number back to a category. High calculated values should trigger review of relay clearing, maintenance settings, current-limiting options, remote operation, and de-energization. Medium-voltage equipment follows its applicable calculated or table-method scope; verify the current edition and equipment details.
What to collect before you calculate
Per lineup and section: one-line with the protective-device stack and settings (breaker frame, trip unit, relay curves — the clearing time at the arcing current is the number that decides everything here), available fault current at the lineup from the utility letter or point-to-point calculation, bus gap and enclosure dimensions, and whether a maintenance-mode setting exists and who is authorized to enable it. For relay-protected gear, the coordination study or relay settings file replaces breaker faceplate photos.
Other equipment guides
- Electrical panels and panelboards
- Transformers
- Motor control centers
- Disconnects
- Industrial control panels
Get the label numbers for your equipment in the free arc flash calculator — panel specs in, a reviewable record and label preview out. The master field list lives at arc flash label requirements; sizes and stock at the arc flash label template page.
Direct answers
Frequently asked questions
What PPE category does the NFPA 70E table assign to 600 V switchgear?
Category 4 — for 600 V class metal-clad switchgear at up to 35 kA available fault current and 0.50 seconds clearing. That row tells you the table expects high energy here; many real lineups compute outside it and need the incident-energy calculation.
Why can switchgear exceed 40 cal/cm²?
Clearing time is often the decisive input. Switchgear can sit close to a stiff source while an upstream relay or breaker takes longer to clear. Faster relaying, validated maintenance settings, current-limiting equipment, remote operation, and de-energization should be evaluated by the engineer and equipment owner.
What size label does a switchgear lineup take?
Public specifications put 6×8 in labels on large switchgear lineups where the label must read from a distance; individual sections take the standard 4×6 in. Each electrically distinct section gets its own values.
Source trail
Sources
Standards references identify the applicable document or section where possible. Standards text may require licensed access. Report a factual issue through the process on our corrections page.