Click to enlarge - 440R-N23112-23_Product


The Allen-Bradley Guardmaster Minotaur MSR126R/T is a safety monitoring relay that provides the very basics for safety control systems in a 22.5 mm package.

The MSR126R/T is designed for connection to a single channel safety gate, a single channel e-stop or a light curtain that provides cross fault detection. The MSR126.1R/T is designed for connection to a dual channel safety gate or e-stop, as it performs cross fault detection across the inputs.

The MSR126R and MSR126.1R are designed for applications where a monitored manual reset is required. Monitored manual reset requires the use of a momentary normally open switch to activate the outputs.

The MSR126T and MSR126.1T are designed for applications where automatic/manual reset is required.

The outputs are only two normally open safety-rated outputs. The safety outputs have independent and redundant internal contacts to support the safety function.


LED Indicators

Green Power On
Green K1 Closed
Green K2 Closed


Safety Ratings
Standards EN 954-1, ISO 13849-1, IEC/EN 60204-1, IEC 60947-4-1, IEC 60947-5-1, ANSI B11.19, AS 4024.1
Safety Classification Cat. 4 per EN 954-1 (ISO 13849-1), SIL CL3 per EN IEC 62061, PLe per ISO 13849-1
Functional Safety Data ⋆ 
Note: For up-to-date information, visit
PFHD: < 1.45 x 10-9
MTTFd: > 398 years
Suitable for performance levels Ple (according to ISO 13849-1:2006) and for use in SIL3 systems (according to IEC 62061) depending on the architecture and application characteristics
Certifications CE Marked for all applicable directives, cULus, c-Tick, and BG
Power Supply
Input Power Entry 24V AC/DC, 115/230V AC
Power Consumption 4 W
Safety Inputs 1 N.C., 2 N.C., or LC
Input Simultaneity Infinite
Input Resistance, Max. 90 W
Reset Auto./Manual or Monitored Manual
Power On Delay/
Recovery Time
300 ms/100 ms
Response Time 15 ms
Safety Contacts 2 N.O.
Thermal CurrentIlth Max 6 A in one current path (nonswitching)
Rated Impulse withstand Voltage 2500V
Switching Current @ Voltage, Min. 10 mA @ 10V
Fuses, Output External 6 A slow blow or 10 A fast acting
Electrical Life (Operations) (With surge suppression)
250V AC/6 A/1500VA cosf = 1…0.1 M
250V AC/2.5 A/625VA cosf = 1…0.5 M
250V AC/1.5 A/375VA cosf = 0.35…0.3 M
250V AC/5 A/1250VA cosf = 0.6…0.1 M
24V DC/2 A/48 W = 1 M
10V DC/0.01 A/0.1 W = 2 M
Mechanical Life 2,000,000 operations
Utilization Category UL: B300, 5 A/250V AC, 24V AC, 6 A/24V DC
Resistive: AC-1 6 A/250V AC  
Resistive: DC-1 6 A/24V DC  
Inductive: AC-15 6 A/250V AC 6 A/125V AC
Inductive: DC-13 3 A/24V DC 6 A/24V DC @ 6 ops/min
Environmental and Physical Characteristics
Enclosure Type Rating/
Terminal Protection
IP40 (NEMA 1), DIN 0470/
IP20, DIN 0470
Operating Temperature [C (F)] -5…+55 ° (23…131 °)
Vibration 10…55 Hz, 0.35 mm
Shock 10 g, 16 ms 100 shocks
Mounting 35 mm DIN Rail
Weight [g (lb)] 24V DC: 160 (0.35); 115/230V AC: 215 (0.47)
Conductor Size, Max. 0.2…4 mm2 (24…12 AWG)
⋆ Usable for ISO 13849-1:2006 and IEC 62061. Data is based on the following assumptions:
- Mission time/Proof test interval of 20 years
- Functional test at least once within six-month period

Product Selection

Inputs Safety Outputs Auxiliary Outputs Terminals Reset Type Power Supply Cat. No.
Light Curtain or Single Channel (MSR126T) 2 N.O. None Fixed Auto./Manual 24V AC/DC 440R-N23117
115V AC 440R-N23116
230V AC 440R-N23115
Dual Channel 2 N.C. (MSR126.IT) 24V AC/DC 440R-N23114
115V AC 440R-N23113
230V AC 440R-N23112
Light Curtain or Single Channel (MSR126R) Monitored Manual 24V AC/DC 440R-N23123
115V AC 440R-N23122
230V AC 440R-N23121
Dual Channel 2 N.C. (MSR126.IR) 24V AC/DC 440R-N23120
115V AC 440R-N23119
230V AC 440R-N23118

Approximate Dimensions

Dimensions are shown in mm (in.). Dimensions are not intended to be used for installation purposes.

Click to enlarge - 440R-N231#_Dim

Block Diagram

Click to enlarge - 440R-N23112-23_Block Diagram

Typical Wiring Diagrams

Click to enlarge - 440R-N23112-23_Wiring 01   Click to enlarge - 440R-N23112-23_Wiring 02
115/230V Supply, 24V DC Light Curtain,
Monitored Manual Reset, Monitored Output
  Dual Channel E-Stop Input,
Monitored Manual Reset, Monitored Output
Click to enlarge - 440R-N23112-23_Wiring 03   Click to enlarge - 440R-N23112-23_Wiring 04
Single Channel Safety Gate,
Automatic Reset, No Output Monitoring
  Dual Channel E-Stop, Automatic Reset,
No Output Monitoring