Arc energy and lock-out check

Defaults are invented (14 A, 64 V arc, 1.0 s clearing, an 8 kW array, 5 arc events). The 750 J and 2.5 s limits and the five-minute delay are the figures printed in a SolarEdge application note (v1.0, April 2025) for UL 1699B (2018) and IEC 63027. The note gives no formula: the clearing-time maths assumes constant arc power and is our arithmetic. The ledger assumes the inverter restarts itself after each of the first four events, as the SMA and Huawei pages describe. SolarEdge's North America note says a qualified person must re-enable inverters, so the ledger does not fit that case. Check your inverter manual.

1. Arc energy

Arc voltage (V)

Arc current (A)

Time to interrupt (s)

2. Lock-out ledger

Array output when it trips (kW)

Restart delay after each arc (min)

Arc events in 24 hours (whole number)

Hours until a manual reset (if locked)

Design aid only. It does not model arc detection. It compares one arc with the two quoted limits and counts lost output.