3SU1156-6AA40-1BA0

1. Overview

The Siemens 3SU1156-6AA40-1BA0 is a complete indicator light device from the SIRIUS ACT 3SU1 product family. It is a 22mm round, metal-housing pilot light in green color, equipped with a flat smooth lens and an integrated LED module rated for 24V AC/DC operation. The "-1BA0" suffix designates spring-loaded (push-in) terminals, distinguishing it from the more common "-1AA0" screw-terminal variant. It is sold as a complete assembly including the metal front ring/holder and the LED module, ready for panel mounting without further accessory purchases. The 3SU1156 series occupies Siemens' metal-bodied tier of the SIRIUS ACT portfolio, above the 3SU1152 plastic variants, and below multi-position or illuminated-pushbutton derivatives.

2. User Sentiment

The SIRIUS ACT 3SU1 indicator light family is widely regarded in industrial automation as a reliable, premium-quality pilot light solution. Professionals favor the robust metal construction, the high ingress-protection ratings (IP66/IP67/IP69K), and the modular snap-on design that enables one-handed installation without tools. The integrated LED module approach is appreciated for consistent illumination and long service life. The spring-loaded terminal variant (1BA0) is particularly valued in high-vibration environments and for faster panel wiring compared to screw-terminal versions. No significant negative sentiment has been identified for this model; occasional commentary notes that Siemens pricing is premium relative to generic alternatives, though durability and certification compliance justify the cost in industrial settings.

3. Real-World Applications

SIRIUS ACT 3SU1156 green indicator lights are deployed extensively in:

• Machine tool panels: "Machine running" or "power on" status indication on CNC and turning centers.
• Process control cabinets: Status indication for pumps, motors, and conveyor systems.
• Pharmaceutical and food processing: IP69K rating makes them suited for washdown environments requiring high-pressure cleaning.
• Hazardous area equipment: ATEX certification enables use in Zone 2/22 explosive atmospheres.
• Building automation and HVAC: Compact 22mm format fits standard panel cutouts common across global facilities.
• Water treatment and utilities: Corrosion-resistant metal housing withstands oils and caustic cleaning agents. The spring-loaded terminal variant (1BA0) is preferred in applications with vibration or where rapid wiring changes occur, such as modular machine panels.

4. Technical Specifications

• Type: Complete indicator light device (front element + holder + LED module), 22mm round
• Housing material: Metal (shiny/polished finish)
• Lens: Flat, smooth, green
• Supply voltage: 24V AC/DC (integrated LED module)
• Terminal type: Spring-loaded (push-in) terminal — distinguishes 1BA0 from 1AA0 screw terminal
• Mounting hole diameter: 22.3mm
• Protection rating: IP66 / IP67 / IP69K (front face); IP20 (terminals)
• Standards/Certifications: ATEX (IEC 60079-11:2011), CE, UL (series-level)
• Installation: Snap-on one-handed assembly; SIRIUS ACT modular system
• Related 230V variant: 3SU1156-6AA40-1AA0 (screw terminal, 230V AC) — same form factor
• Dimensions (approx.): ~61.5mm L × 39mm W × 40mm H (complete assembly)
• Series siblings: 3SU1156-6AA20 (red), 3SU1156-6AA30 (yellow), 3SU1156-6AA60 (white)
• PROFINET: Optional via SIRIUS ACT system accessories

5. Ordering & Compatibility

The 3SU1156-6AA40-1BA0 is a Siemens standard catalog item available through Siemens Industry Mall, authorized distributors (Kempston Controls, automation24, Conrad Electronic, TME, Newark/Farnell), and industrial automation suppliers globally. The SIRIUS ACT 3SU1 system is designed for 22.3mm panel cutouts, compatible with standard IEC/NEMA panel designs. The complete-device format (3SU1156) means no additional LED module or holder purchase is required. For 230V AC applications on the same panel, the 3SU1156-6AA40-1AA0 is the direct equivalent. Plastic-housing lower-cost alternative is 3SU1152-6AA40-1BA0. The modular system also allows separate ordering of front elements (3SU1001 series) and LED modules for retrofits. Ribbon cable piercing accessories and PROFINET communication modules are available as system extensions.

6. Known Issues

No significant issues reported for this specific model. General notes from the series: the snap-on holder design, while convenient for installation, requires correct alignment during assembly to ensure IP rating integrity. The spring-loaded terminal variant may require a small flat screwdriver or insertion tool depending on wire gauge. Some distributors note that 24V and 230V variants share identical external appearance — verify part number suffix carefully when ordering to avoid voltage mismatch.