Electrical plug connector with radially actuated secondary locking, and electrical plug-in connection system

An electrical plug connector, comprising:

• a plug contact at one end of a cable,
• a contact carrier,
• a plug housing,
• a primary locking element, and
• a secondary locking element,
• wherein the plug contact is accommodated in the contact carrier,
• wherein the contact carrier is accommodated in the plug housing,
• wherein both the primary locking element and the secondary locking element are each configured so as to fix the plug contact in the contact carrier against removal from the contact carrier by pulling in an axial direction parallel to a longitudinal direction of the cable,
• wherein the secondary locking element is configured as a separate component which is displaceable relative to the contact carrier,
• wherein the secondary locking element, the contact carrier and the plug contact are configured such that the secondary locking element is brought from a pre-fixed intermediate position into a fixed end position by displacement in a radially inward direction relative to the contact carrier, the secondary locking element being reversibly detachably held on the contact carrier in the pre-fixed intermediate position and the secondary locking element being firmly held on the contact carrier in the fixed end position and bearing, at least in areas, against the plug contact such that the plug contact is fixed in the contact carrier by the secondary locking element against the removal from the contact carrier by pulling in a direction parallel to a longitudinal direction of the cable.