Testing medical device power to IEC 61000-4-11 / -4-13 / -4-14

Immunity testing runs the opposite way round to most power test: you are not supplying medical power supplies and powered devices cleanly, you are attacking them. Running on mains AC, often with battery backup, what you have to demonstrate is immunity to mains disturbance where failure has patient consequences. IEC 61000-4-11 / -4-13 / -4-14 defines the attack — voltage dips and interruptions, inrush drive capability — and deliberately leaves 400 Hz to other standards. The demanding part is rarely the voltage. It is aC source with 500 A peak inrush drive, 1–5 µs dip edges, phase-of-dip control, and full per-phase arbitrary waveform synthesis with independent harmonic and interharmonic amplitude and phase control.

What you are testing

Device under test: medical power supplies and powered devices
Bus: mains AC, often with battery backup
Who buys this: medical device manufacturers approaching market approval

What IEC 61000-4-11 / -4-13 / -4-14 does not cover

400 Hz
DC bus transients
reliability duration testing

If your programme needs those, they come from a different standard and often different hardware.

The limits this test has to reproduce

The failure consequence changes the test discipline rather than the test levels. Traceability and repeatability carry as much weight here as the disturbance itself.

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
Generator rise/fall	1–5 µs	61000-4-11 §6
Voltage fluctuation	Class 2 ΔU ±8% U_n; Class 3 ΔU ±12% U_n	61000-4-14

The clauses medical programmes actually face, as published in IEC 61000-4-11 / -4-13 / -4-14. See every limit in IEC 61000-4-11 / -4-13 / -4-14. Certification work should be run against the published standard.

What decides the rig here

The requirements that separate a system that can run this programme from one that only meets the headline numbers.

Traceability weighs as much as the level

Every setpoint and measured response has to survive audit. The data path is part of the qualification, not an accessory to it.

Battery-backed designs need the handover tested

The interesting failure is rarely the disturbance itself — it is the transition to and from backup power.

Repeatability is a safety argument

A test that passes intermittently is not evidence. Run-to-run variance is a finding in this sector, not noise.

Send us the clauses you have to satisfy

We will come back with the source and load capability that covers them — and tell you plainly if something in your spec needs hardware we would not supply.

Talk to an engineer