IEC 60255-22-2

Overview

IEC 60255-22-2 is the IEC standard that defines electrostatic discharge (ESD) tests for measuring relays and protection equipment used in power system protection. Based on IEC 61000-4-2, it sets general requirements and test methods to verify that relays, control, monitoring and process-interface devices do not mal-operate when energized and subjected to ESD. The standard emphasizes realistic test set‑ups, defined test severity levels, and clear reporting so manufacturers and test labs can demonstrate immunity and operational reliability.

Key topics

• Scope and applicability: Applies to measuring relays and protection equipment and associated control/monitoring/process interface devices used in power system protection.
• Test objectives: Confirm that equipment under test (EUT) remains functional and does not produce unintended operations (nuisance tripping, false alarms, loss of protection) during and after electrostatic discharges.
• Test methodology: Uses the ESD principles and discharge modes defined in IEC 61000-4-2 (contact and air discharge) and adapts them to relay/protection equipment test conditions.
• Test set-up and instrumentation: Specifies realistic mounting, grounding, cabling and monitoring arrangements to reproduce operational conditions while applying ESD stresses.
• Severity levels and improvements: Defines required test severity levels and documents recent updates that raise test severity, refine test set-up, and improve test reporting.
• Monitoring and criteria: Requires observation and recording of malfunctions, temporary disturbances and permanent failures; pass/fail criteria focus on absence of unacceptable mal-operation.
• Test reporting: Requires clear test reports describing test configuration, levels applied, observed behavior, and conclusions on immunity.

Applications

• Product development and design validation for protection relays, numerical relays, and interface modules.
• Type testing and compliance verification by manufacturers and independent EMC test laboratories.
• Procurement specifications and acceptance testing for utilities and system integrators to ensure equipment reliability in substations and control centers.
• Failure analysis and mitigation planning to reduce the risk of nuisance trips and protection outages due to ESD.

Who uses this standard

• Relay and protection-equipment manufacturers
• EMC and type-testing laboratories
• Protection and control engineers in utilities and industry
• Certification bodies and compliance officers
• Procurement teams specifying immunity requirements for substation equipment

Related standards

• IEC 60255 series (measuring relays and protection equipment)
• IEC 61000-4-2 (Electrostatic discharge immunity test) - primary reference for test techniques and discharge modes

Keywords: IEC 60255-22-2, electrostatic discharge tests, ESD immunity, measuring relays, protection equipment, IEC 61000-4-2, power system protection, EMC testing.