Safe Box electronic evaluation SIL3

Safe Box is an extension of the redundant absolute shaft information systems LIMAX3R and LIMAX4R. It serves as an additional component for monitoring the position and speed of the car, as well as the shaft and cabin doors. The system ensures important safety-relevant requirements in the shaft, e.g. limit switch function, speed limitation, also relative to the distance to the shaft end, door-bridging function for leveling and readjust with open doors, detection of unintended car movement with open doors. In case of error, the safety circuit will be opened and/or the clasp brake will be triggered. The Safebox is SIL3 certified by TÜV and complies the requirements of the EN81-20/50 norm.

  • Safety function unit for the redundant shaft information systems LIMAX3R or LIMAX4 R
  • Replaces electromechanical components in the elevator shaft
  • Up to 3 pairs of safety relay pairs for safety-relevant switching and control functions
  • Up to 5 safety inputs, 1 electronical output and 1 safety circuit input
  • CANopen interface DS406, others on request,
  • RS485 for sensor communication
  • EC type examination tested (EN 81-20/50)
  • TÜV certification for SIL3

Product inquiry


Housing materialaluminium
Housing dimensions
(W x B x H)
203 x 125 x 66 mm
Signal cable (SCA and PIO)standard: 2 m, optional: 1.0 or 5.0 m
Connectionssensor: pluggable M 12 socket, SCA, PIO cable: open cable ends, optional with plug connector
Weightapprox. 2000 g (without cable), cable: approx. 60 g/m


Power supply voltage24 VDC, -25 % / +20 % (stabilized)
Residual ripple< 100 mVpp
Current consumptionmax. 500 mA
Battery voltage12 VDC ± 20 %
InterfacesCANopen - DS406, other on request, RS485 for sensor communication
Number of safe inputs5
Number of safety circuit inputs1
Number of electronic outputs1


Number of safety relays3 (OC, NOC, SGC)
Voltage110 VAC / 220 VAC / 24 VDC
Contact load max. 1 A
Response time< 55 ms


Achieved SIL SIL3
Fulfilled standardsEN81-20
Type-examination EC according to EN81-20



Storage temperature-20 ... +70 °C 
Operating temperature0 ... +65°C, -25 ... +85 °C on request
Humiditiy95 %, non-condensing
Operating heightmax. 2000 m above sea level
Protection classIP54 (according to EN60529), higher on request
Interference emission/ immunity EN 12015 / EN 12016
Vibration/ shock resistanceEN 60068-2-6 / EN 60068-2-27 / EN 60068-2-29
Delay by motor brake> 1.7 m/s²
Delay by lift control< 1.2 m/s²
Buffer dimensioning> 0.63 m/s² (inspection speed)




Flyer Safe Box


Safe Box

CANopen Specifications

LIMAX Safe SG/SC protocol description of the CANopen interface