• DIN Rail Mounting
  • Space Saving 3-Channel Design
  • Compatible with Migatron’s RPS-409A-IS, RPS-
  • 409A-IS2 and RPS-409A-IS3 Ultrasonic Sensors

  • ATEX, IECEx, & UL/cUL Approvals
Image of ZSB-409A Safety Barrier.
The ZSB-409A is a 3-channel dc positive polarity zener safety barrier for use in intrinsic safety applications. The 3-channel design has one 24 V dc channel and two 10 V dc channels. The ZSB-409A is compatible with Migatron’s RPS-409A-IS, RPS-409A-IS2 and RPS-409A-IS3 ultrasonic sensors, and combines all of the connections into one convenient package. The ZSB-409A provides for the safe operation of an intrinsically safe electrical apparatus installed in a hazardous gas or dust environment classified as Zone 0, 1, 2, 20, 21, or 22 for ATEX/IECEx, and Class I, II, or III for UL/cUL.
The ZSB-409A safety barrier is intended for indoor or outdoor use in locations where the temperature does not exceed the specified range (Ta) of the safety barrier. The safety barrier must be installed in a safe area; typically in racks or control cabinets with an appropriate level of protection from dust and liquids. The ZSB-409A is designed for easy installation onto standard 35 mm DIN-Rail, and is fitted with an insulated wire for making the ground connection. Refer to Control Drawing No. Ex05121109 for further information on installation.


Safe Area Terminal Connections

Channel#TerminalsSupply Voltage
maximum (V dc)
Fuse Rating
17 & GND25.550320 (terminals 7 to 3)
25 & GND10.4502718 (terminals 5 to 1)
36 & GND10.4502718 (terminals 6 to 2)

GND = Safe Area ground terminals are 8, 13, 14, 15, & 16

The maximum voltage Um applied to a non-intrinsically safe apparatus or an intrinsically safe associated apparatus/equipment is 250 V rms or dc.

  • Entity Parameters:
  • See Control Drawing No. Ex05121109
  • Connections:
  • Cage terminals, each maximum 12 AWG solid/stranded
    wire type Cu, torque 5-7 Lb. In. (0.6-0.8 Nm)
  • Ambient Temperature:
  • -40°C ≤ Ta ≤ +60°C (-40°F ≤ Ta ≤ +140°F)
  • Humidity:
  • 0 – 95% Non-Condensing
  • Housing Material:
  • Polyamide
  • Protection:
  • Model ZSB-409A must be installed inside an end-use enclosure with suitable
    ratings for the environment, with at least an ingress protection rating of IP20.
  • Mounting:
  • DIN-Rail
  • Weight:
  • approximate 270 g (9.5 oz.)
  • Dimensions:
  • Length = 99 mm (3.9″), Width = 22.5 mm (0.9″), Height = 114.5 mm (4.5″)

Explosion Protection and Approvals:

(ATEX) DEMKO 13 ATEX 1214149X(IECEx) IECEx UL 13.0030X(UL/cUL) File # E226209
I M(1) [Ex ia Ma] I[Ex ia Ma] IClass I, Division 1, Groups A, B, C, and D;
II (1) G [Ex ia Ga] IIC[Ex ia Ga] IICClass II, Division 1, Groups E, F, and G; and
II (1) D [Ex ia Da] IIIC[Ex ia Da] IIICClass III, Division 1
ZSB-409A3-Channel DC Positive Polarity Zener Safety Barrier
F24-7942744DIN-Rail (6″ section) – Sold Separately
F33-5441504DIN-Rail Grounding Block – Sold Separately
View Data Sheet