Add-on unit for emergency release according to EN 81-21

The add-on unit N21-11AEO is designed to retrofit the monitoring of an emergency release triangle at shafts with insufficient protective room. It is mounted through an emergency release opening so that a KRONENBERG triangular key e.g. type C160 can be inserted through the existing triangle.


  • electrical monitoring of the emergency release by positively driven normally closed contact and additional signal contact (normally open contact)
  • mounting in front of the emergency release opening, therefore ideal for retrofitting of swing and automatic doors
  • actuation with Kronenberg triangular key (accessories – please order separately); the triangular key is pushed through the switch on the existing triangle
  • compact dimensions
  • robust housing made of stainless steel
  • no visible fixing elements
  • emergency release possible at any time
  • function independent of direction of rotation

Order information codes

Technical data

norms EN 81-20, EN 81-21, EN 81-50
switching capacity 24 V DC / 2 A
contact material fine silver
connection by slot nut max. 2.5 mm²
level of protection IP40
ambient air temperature -10 °C up to +75 °C
weight 300 g