ⓘ Replacement notice: CISPR 24 (EN 55024) has been replaced by CISPR 35 (EN 55035) as the immunity standard for multimedia equipment. New product compliance submissions should use EN 55035. Compatible Electronics maintains accreditation for EN 55024 to support legacy products and markets still in transition.
What is EN 55024 / CISPR 24?
EN 55024 is the European harmonized edition of CISPR 24, specifying the immunity characteristics, limits, and methods of measurement for information technology equipment (ITE). It is the immunity companion standard to CISPR 22 (EN 55022), and together they formed the complete EMC compliance standard set for ITE prior to the introduction of the multimedia equipment standards CISPR 32 and CISPR 35.
EN 55024 has been superseded by EN 55035 (CISPR 35) for most multimedia equipment. However, EN 55024 remains relevant for: legacy products still in the approval pipeline, certain markets where the transition has not yet occurred, and products where older versions of the standard are still referenced in applicable regulations. Compatible Electronics remains accredited for EN 55024 testing alongside EN 55035.
Immunity Requirements Under EN 55024
EN 55024 references the IEC 61000-4 basic immunity standard series. For ITE, the following phenomena and test levels apply:
1
ESD (IEC 61000-4-2)
±4 kV contact, ±8 kV air discharge. ESD testing verifies that the equipment does not malfunction when subjected to electrostatic discharges from human operators.
2
Radiated RF (IEC 61000-4-3)
3 V/m, 80 MHz to 1 GHz (with additional spot frequencies). Verifies the equipment operates correctly in the presence of radio frequency fields from nearby transmitters.
3
EFT/Burst (IEC 61000-4-4)
±1 kV on power lines, ±0.5 kV on I/O lines. Simulates switching transients from inductive loads on the supply circuit.
4
Surge (IEC 61000-4-5)
±0.5 kV (L-L) / ±1 kV (L-E) on mains ports. Simulates overvoltages from lightning and mains switching events.
5
Conducted RF (IEC 61000-4-6)
3 V (r.m.s.), 150 kHz to 80 MHz. Tests immunity to conducted RF disturbances induced onto power and signal ports.
6
Voltage Dips (IEC 61000-4-11)
Voltage reductions and short interruptions at defined durations. Tests ability to withstand brief mains supply disturbances.
| Standard Version | Locations Accredited |
|---|
| EN 55024 (2010) | Lake Forest/Silverado, Brea, Newbury Park |
| CISPR 24 (2010) + A1 (2015) | Lake Forest/Silverado, Brea |
| IEC/CISPR 24 (1997) and EN 55024 (1998) + A1 (2001), A2 (2003) | Newbury Park |
