Suitable PPE against the thermal effects of arc faults must be worn – especially during maintenance when the switchgear installation cannot be shut down. 1) Switchgear assemblies or simply assemblies as per IEC 61439-2:2021; i.e. up to a rated operational voltage of 1,000 V AC or 1,500V DC 2) Among other things, operation is the actuation of main current devices, such as circuit breakers, fuse switches / load disconnectors or motor starter combinations Further technical measures for the protection against arc faults possible, such as dedicated switch tripping setting for exclusively in maintenance situations, setting optimisation of the switch for hazard reduction (reducing arc fault energy). Internal subdivision, insulation of the live components for risk minimisation (probability of occurrence lower). 3) Among other things, maintenance is the cleaning, renovation or replacement of devices or parts of switchgear assemblies. 4) Availability is the period of time in which the switchgear assembly is available for operation / the maximum period of time the power may be out. Assessments and estimates are provided by the operator. 5) Note the settings of tripping characteristics and actual turn-off time of the protective devices. Note the selectivity calculation here. This turn-off time must not exceed the test result of the "passive arc fault protection". The operator is responsible for the set-up. (Status while devising this dialogue guideline 02/2023) 6) Fire risk is the minimisation and prevention of fires in the switchgear assembly through disconnection within the millisecond range. This ensures preventive fire protection. * Class A arc fault protection (protection of people) 5 * Class B arc fault protection (protection of persons and assemblies) 5 * Class C arc fault protection (protection of persons and assemblies) 5 No special requirement for arc fault protection Redundant switchgear* assembly recommended. New and separate assessment of the protection goals for the protection of people and systems! Additional equipment of an active arc fault system recommended * Class C AND active arc fault protection integrated and tested as per IEC 61439-2:2021 With user/manufacturer agreement for testing with open door or cover. In addition: Suitable PPE against the thermal effects of arc faults IEC 61482-2 APC 1 or APC 2/ PPE1, 2, 3 or 4 * Class C AND active arc fault protection integrated and tested as per IEC 61439-2:2021 Doors and covers properly closed DEHNshort DEHNcare DEHNshort * Class C AND active arc fault protection integrated and tested as per IEC TS 63107 Doors and covers properly closed. The active arc fault protection should be certified to VdS 2344 (fire protection technology systems) and 2349 (reliable electrical installation) in order to be accepted by property insurers. DEHNshort Switchgear assembly as per IEC 61439-2:2021 Proof of inspection as per IEC TR 61641:2014 in arc faults* No measures necessary Technical measures necessary (standard requirements) Technical measures necessary (strict requirements) Technical measures necessary (very strict requirements) for DEHNarX analysis Assessment of hazards and risks e.g. as per DGUV-I 203-077 or IEEE 1584 (2018) & NFPA 70E (2021) Shutdown always possible Shutdown not possible Distance On the switchgear installation 2–4 hours 7–10 days 2–4 weeks 1–2 months Seconds/minutes, not tolerable Personal protection Personal protection Assembly protection Assembly protection Maintenance 3 Assembly open Operation 2 Assembly closed Availability 4 Tolerable downtime Fire protection Fire risk reduction 5 inside a switchgear assembly IEC 61439-2:2021 when planning new installations Dialogue guideline: Protection measures against arc faults Maintenance 3 Assembly open Shutdown always possible Shutdown not possible Operation 2 Assembly closed Distance On the switchgear installation Availability 4 Tolerable downtime Seconds/minutes, not tolerable 2–4 hours 7–10 days 2–4 weeks 1–2 months Fire protection Fire risk reduction 5 No measures necessary No special requirement for arc fault protection Operation 2 Assembly closed Distance Switchgear assembly as per IEC 61439-2:2021 Operation 2 Assembly closed No measures necessary Technical measures necessary (standard requirements) Technical measures necessary (strict requirements) for DEHNarX analysis Assessment of hazards and risks e.g. as per DGUV-I 203-077 or IEEE 1584 (2018) & NFPA 70E (2021) Operation 2 Assembly closed On the switchgear installation Switchgear assembly as per IEC 61439-2:2021 Proof of inspection as per IEC TR 61641:2014 in arc faults* No measures necessary No special requirement for arc fault protection * Class A arc fault protection (protection of people) 5 Switchgear assembly as per IEC 61439-2:2021 Proof of inspection as per IEC TR 61641:2014 in arc faults* Technical measures necessary (standard requirements) Switchgear assembly as per IEC 61439-2:2021 Proof of inspection as per IEC TR 61641:2014 in arc faults* Technical measures necessary (strict requirements) * Class C AND active arc fault protection integrated and tested as per IEC 61439-2:2021 Doors and covers properly closed DEHNshort Maintenance 3 Assembly open Shutdown always possible No measures necessary No special requirement for arc fault protection Switchgear assembly as per IEC 61439-2:2021 Maintenance 3 Assembly open Shutdown not possible Technical measures necessary (very strict requirements) * Class C AND active arc fault protection integrated and tested as per IEC 61439-2:2021 With user/manufacturer agreement for testing with open door or cover. In addition: Suitable PPE against the thermal effects of arc faults IEC 61482-2 APC 1 or APC 2/ PPE1, 2, 3 or 4 for DEHNarX analysis Assessment of hazards and risks e.g. as per DGUV-I 203-077 or IEEE 1584 (2018) & NFPA 70E (2021) Switchgear assembly as per IEC 61439-2:2021 DEHNshort PSAgS Proof of inspection as per IEC TR 61641:2014 in arc faults* No special requirement for arc fault protection Switchgear assembly as per IEC 61439-2:2021 1–2 months Availability 4 Tolerable downtime * Class B arc fault protection (protection of persons and assemblies) 5 2–4 weeks Proof of inspection as per IEC TR 61641:2014 in arc faults* Switchgear assembly as per IEC 61439-2:2021 Availability 4 Tolerable downtime * Class C arc fault protection (protection of persons and assemblies) 5 7–10 days Proof of inspection as per IEC TR 61641:2014 in arc faults* Switchgear assembly as per IEC 61439-2:2021 Availability 4 Tolerable downtime Proof of inspection as per IEC TR 61641:2014 in arc faults* Switchgear assembly as per IEC 61439-2:2021 * Class C AND active arc fault protection integrated and tested as per IEC 61439-2:2021 Doors and covers properly closed DEHNshort 2–4 hours Availability 4 Tolerable downtime Redundant switchgear* assembly recommended. New and separate assessment of the protection goals for the protection of people and systems! Additional equipment of an active arc fault system recommended Seconds/minutes, not tolerable Switchgear assembly as per IEC 61439-2:2021 Availability 4 Tolerable downtime Fire protection Fire risk reduction 5 * Class C AND active arc fault protection integrated and tested as per IEC TS 63107 Doors and covers properly closed. The active arc fault protection should be certified to VdS 2344 (fire protection technology systems) and 2349 (reliable electrical installation) in order to be accepted by property insurers. Switchgear assembly as per IEC 61439-2:2021 DEHNshort Proof of inspection as per IEC TR 61641:2014 in arc faults*