OMRON D4B — Limit Switches

Omron D4B: safety limit switch with metal housing, direct opening NC contacts, IP67, Ithe 20 A, −40 to 80 °C.

Omron D4B — Safety limit switch with metal housing (direct opening)

Status: In production

Brand: Omron

Product: Safety limit switch with metal housing (direct opening)

Safety: Direct opening NC contacts (EN60947-5-1, TÜV Rheinland)

Degree of protection: IP67 (EN60947-5-1)

Mechanical durability: 30,000,000 operations min. (snap-action)

Conventional enclosed thermal current (Ithe): 20 A

Operating temperature: −40 to 80 °C (no icing)

Request a quote for price and stock

Omron D4B is a series of safety limit switches in a rugged metal housing. Its direct opening mechanism and TÜV approval make it suitable for both safety and non-safety applications. The direct opening mechanism on the NC contacts forcibly opens the contacts when faults such as contact welding occur. Lever setting safety is ensured by a gear that engages the operating position indicator plate and the lever. The head seal structure is strengthened (TÜV: IP67; UL: NEMA 3, 4, 4X, 6P and 13). The standard type operates from −40 to 80 °C. Certified standards: UL, CSA, EN (TÜV) and CCC.

Actuators include roller lever (resin or stainless steel roller), adjustable roller lever, adjustable rod lever, plunger and roller plunger; built-in switches are 1NC/1NO snap-action, 1NC/1NO slow-action and 2NC slow-action. The conduit opening is G1/2 (PF1/2) or M20 and wiring is made on a screw terminal block. On roller lever models the operating direction can be set to left, right or both without tools, and the head can be mounted in four directions. Snap-action models reach 30,000,000 mechanical operations min. Adjustable lever models are, by construction, general-purpose limit switches.

Omron D4B technical specifications

General
Housing materialAluminium
ConnectionScrew terminal block (M3.5)
Conduit openingG1/2 (PF1/2) or M20, 1 conduit, bottom
Protection against electric shockClass I (with ground terminal)
StandardsEN60947-5-1, EN50041, EN60204-1, EN ISO 14119
ApprovalsTÜV Rheinland, UL508, CSA C22.2 No.14, CCC (GB/T14048.5)
WeightApprox. 250 g
Safety ratings
Direct opening mechanismOn NC contacts, certified to EN60947-5-1; not on adjustable roller lever and adjustable rod lever models
Electrical characteristics
Utilization category AC-152 A / 400 V
Conventional enclosed thermal current (Ithe)20 A
Rated insulation voltage (Ui)600 V
UL/CSA ratingA600
Impulse withstand voltageSame polarity: 2.5 kV (snap-action), 4 kV (slow-action); different polarity: 4 kV; terminal to ground 4 kV
Conditional short-circuit current100 A
Short-circuit protection10 A fuse type gI or gG (IEC60269)
Inrush current30 A max.
Contact resistance25 mΩ max.
Insulation resistance100 MΩ min. (at 500 VDC)
Contact gapSlow-action: 2 × 2 mm min.; snap-action: 2 × 0.5 mm min.
Rated frequency50/60 Hz
Mechanical and connection
Mechanical durability30,000,000 operations min. (snap-action), 10,000,000 operations min. (slow-action)
Electrical durability500,000 operations min. (10 A resistive load at 250 VAC)
Operating speed1 mm/s to 0.5 m/s
Operating frequencyMechanical 120 operations/minute, electrical 30 operations/minute
Vibration resistance (malfunction)10 to 55 Hz, 0.75 mm single amplitude
Shock resistanceDestruction: 1,000 m/s² min.; malfunction: 300 m/s² min.
Environmental
Degree of protectionIP67 (EN60947-5-1); UL: NEMA 3, 4, 4X, 6P, 13
Operating temperature−40 to 80 °C (no icing)
Operating humidity95% max.
Pollution degree3 (EN60947-5-1)

Omron D4B models

CodeActuatorContactsConduitDirect openingOperating force (OF max.)
D4B-2111NRoller lever (resin roller)1NC/1NO, snap-actionG1/2Yes9.41 N
D4B-2116NAdjustable roller lever1NC/1NO, snap-actionG1/2No9.41 N
D4B-2171NRoller plunger1NC/1NO, snap-actionG1/2Yes18.63 N
D4B-2A11NRoller lever (resin roller)2NC, slow-actionG1/2Yes9.41 N
D4B-2A15NRoller lever (stainless steel roller)2NC, slow-actionG1/2Yes9.41 N
D4B-4111NRoller lever (resin roller)1NC/1NO, snap-actionM20Yes9.41 N
D4B-4117NAdjustable rod lever1NC/1NO, snap-actionM20No2.12 N
D4B-4170NPlunger1NC/1NO, snap-actionM20Yes18.63 N
D4B-4511NRoller lever (resin roller)1NC/1NO, slow-actionM20Yes9.41 N
D4B-4A71NRoller plunger2NC, slow-actionM20Yes18.63 N

Key features

  • Direct opening mechanism on NC contacts certified to EN60947-5-1 (TÜV)
  • Rugged aluminium housing, IP67 and NEMA 3, 4, 4X, 6P, 13
  • 30,000,000 mechanical operations min. on snap-action models
  • Operating temperature −40 to 80 °C on the standard type
  • Gear-engaged lever setting and tool-free left/right operation selection
  • Terminal block for direct wiring, G1/2 or M20 conduit

D4B ordering codes

Part numberDescription
D4B-2111NRoller lever (17.5 mm dia. resin roller), 1NC/1NO snap-action, G1/2
D4B-2116NAdjustable roller lever, 1NC/1NO snap-action, G1/2 (no direct opening)
D4B-2171NRoller plunger, 1NC/1NO snap-action, G1/2
D4B-2A11NRoller lever (resin roller), 2NC slow-action, G1/2
D4B-2A15NRoller lever (stainless steel roller), 2NC slow-action, G1/2
D4B-2A71NRoller plunger, 2NC slow-action, G1/2
D4B-4111NRoller lever (resin roller), 1NC/1NO snap-action, M20
D4B-4115NRoller lever (stainless steel roller), 1NC/1NO snap-action, M20
D4B-4116NAdjustable roller lever, 1NC/1NO snap-action, M20 (no direct opening)
D4B-4117NAdjustable rod lever, 1NC/1NO snap-action, M20 (no direct opening)
D4B-4170NPlunger, 1NC/1NO snap-action, M20
D4B-4171NRoller plunger, 1NC/1NO snap-action, M20
D4B-4511NRoller lever (resin roller), 1NC/1NO slow-action, M20
D4B-4A11NRoller lever (resin roller), 2NC slow-action, M20
D4B-4A71NRoller plunger, 2NC slow-action, M20

Other Omron Limit Switches

  • OMRON D4N — Miniature safety limit switch with plastic housing (direct opening)
  • OMRON WL-N — Two-circuit limit switch series (DPDB)

Models from other brands: Limit Switches

Is this limit switch right for your application?

Share the motion to be detected (direction, speed, stroke), the required actuator (roller lever, plunger, rotary head), the contact configuration, the cable entry, ambient conditions and any safety requirement (positive opening); let’s select the right limit switch together.

Request a quote Back to Limit Switches

All product specifications are subject to change without notice. Source: Omron Europe, industrial.omron.eu/en/products/d4b and model pages (D4B-2111N, D4B-2116N, D4B-2171N, D4B-2A11N); D4B-_N Safety Limit Switch datasheet CSM_D4B-_N_DS_E_10_12 (files.omron.eu) (accessed 25 September 2026).