Siemens · SIRIUS ACT 3SU1 Series

3SU1156-6AA40-1BA0

Active
UL CSA CE

SIRIUS ACT Green LED Indicator Light 24V

Part number: 3SU1 - 1 - 56 - 40 - 1BA0
Siemens SIRIUS ACT 3SU1 Series Introduced circa 2013
Siemens 3SU1156-6AA40-1BA0 — SIRIUS ACT Green LED Indicator Light 24V

Green LED indicator light, Siemens SIRIUS ACT series. 22mm cutout, 24V AC/DC, IP66/IP67/IP69K.

Common Applications

Green LED indicator from the SIRIUS ACT range. Shows running/active status on Siemens automation panels. The integrated LED accepts 24V DC — connects directly to Siemens S7 PLC digital outputs or ET 200SP distributed I/O. Found on motor control centers in automotive plants, pharmaceutical clean rooms, and food/beverage production lines using Siemens automation. The smooth green lens provides uniform illumination visible from several meters away.

Specifications

Certifications
UL, CSA, CE
Color
Green
Cutout Diameter
22mm
IP Rating
IP66/IP67/IP69K
LED Color
Green
LED Voltage
24V AC/DC
Material
Metal
Mounting Type
Panel

You'll Also Need

This is a modular component. For a complete assembly, you may also need:

Installation Quick Reference

Panel cutout: 22mm. Insert from the front, secure with mounting nut.

LED module: Check the voltage rating matches your supply (typically 24V DC or 230V AC). Connect to PLC digital output or relay contact for status indication.

Color meaning (IEC 60204-1): Green = normal/running. Red = fault/danger. Yellow = warning/caution. Blue = mandatory action. White = neutral/general.

Dimensions

Front 22mm cutout panel hole diameter Side panel contact ~45mm depth

Troubleshooting

Light is dim or flickering

Check supply voltage matches the LED module rating. Low voltage causes dimming. If voltage is correct, the LED module is failing — replace it. LED modules have finite life (typically 50K-100K hours).

Light doesn't turn on

Verify voltage at the terminals with a multimeter. Check the PLC output or relay driving the light. LED modules are polarity-sensitive on DC circuits — try reversing the leads.

Where to Buy

Price range

$2.01 — $6.94

across 3 distributors

Quick Specs

Certifications
UL, CSA, CE
Color
Green
Cutout Diameter
22mm
IP Rating
IP66/IP67/IP69K
LED Color
Green

What People Are Saying

+

“Siemens indicators are reliable. Match the LED voltage to your PLC output. Follow IEC 60204-1 color coding — your maintenance team will appreciate consistent standards.”

Reddit r/electricians 18 upvotes View thread →

Data Sources

Specifications and product data sourced from the following references.

Siemens 3SU1156-6AA40-1BA0 Product Page

https://sieportal.siemens.com/en-ww/products-services/detail/3SU11566AA401BA0

Accessed March 29, 2026

Source