Mechanical and equipment engineering, control technology, equipment engineering, railway applications / vehicle construction, the small HA 3 / HA 4 are used wherever space is limited, service-friendly screw connection, simple cable connection through straight cable entry into the contacts, use for railway applications - fire protection in rail vehicles: testing according to EN 45545-2. Requirement set R22 and R23. Hazard level HL1, HL2 and HL3.,
