IEC 60601-1-2 Edition 4.1: Voltage Dips Are Now a Two-Voltage Test
Medical equipment · 3 min read · 29 cited facts
IEC 60601-1-2:2014+A1:2020 — Edition 4.1, published 1 September 2020 — runs voltage dips, short interruptions and voltage variations at both the minimum and the maximum rated input voltage. For the wide-range 100 to 240 V supply that most medical equipment uses, that is two complete runs of the profile rather than one, and it roughly doubles the source time budgeted for that clause.
The amendment also updated the normative reference to IEC 61000-4-11:2004+A1:2017, and the regulatory clock has already run out on the old edition: the FDA stopped accepting Edition 4.0 declarations of conformity in support of premarket submissions after 17 December 2023; a test report generated on a rig configured for the 4.0 clause set no longer supports a US submission on its own.
The profile you run twice
| Parameter | Value | Clause |
|---|---|---|
| Dips, Class 2 | 0%/½ cycle, 0%/1 cycle, 70%/25 (50 Hz) or 30 (60 Hz) cycles | 61000-4-11 Table 1 |
| Dips, Class 3 | adds 40%/10–12 cycles and 80%/250–300 cycles | 61000-4-11 Table 1 |
| Interruptions | 0% for 250/300 cycles | 61000-4-11 Table 2 |
Every row runs once at the minimum rated input and again at the maximum. The disturbance levels do not change between the two passes — the operating point does — so the cost is schedule rather than equipment: settling, sequencing and documentation for two complete profiles where Edition 4.0 planned one.
What the generator still has to do
The generator requirements come from IEC 61000-4-11 §6 and the medical overlay does not relax them: dip edges of 1–5 µs, peak inrush drive of 500 A on 220–240 V supplies and 250 A on 100–120 V supplies, and phase-of-dip control. The two-voltage requirement makes the inrush figure matter twice, because recovery from a dip at either operating point presents a discharged rectifier-capacitor front end to the source.
Scope, before anything is specified: IEC 61000-4-11 applies to equipment drawing up to 16 A per phase (61000-4-11 §1). Above that, IEC 61000-4-34 applies, and the generator question changes with it.
The new test that is not a source test
Edition 4.1 added immunity to proximity magnetic fields, run to IEC 61000-4-39:2017. It needs a field generator, not a programmable AC source, and a quotation that bundles one with the dip bench is quoting equipment you do not need for this clause. Conducted immunity also widened, from signal cables longer than 3 m to signal cables longer than 1 m — again, not a power-input test. Neither change belongs in the AC source budget.
Budgeting the 60601-1-2 immunity clause?
Tell us the supply's rated input range and per-phase current. The two-voltage requirement sets the test time; the inrush requirement sets the source.
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