6EP1961-2BA11 3A Selectivity Module 4-Channel

Introduction to the Siemens 6EP1961-2BA11 SITOP PSE200U Selectivity Module

When a short circuit or overload occurs in a 24 V DC control circuit, the entire system can shut down unexpectedly. The 6EP1961-2BA11 from Siemens solves this problem by selectively isolating only the faulty channel, keeping critical loads powered. As part of the SITOP PSE200U series, this 4-channel selectivity module ensures reliable power distribution in industrial control panels.

With an input rated at 24 V DC and a total input current of 12 A, the module distributes power to four outputs, each rated at 3 A. The threshold value for each output is adjustable from 0.5 A to 3 A via a potentiometer, allowing precise coordination with downstream circuit breakers. A common signaling contact provides a single point for monitoring all channels, simplifying panel wiring and diagnostics.

Key Features and Technical Specifications of the 6EP1961-2BA11

The 6EP1961-2BA11 offers several features that enhance protection and operational flexibility:

• Four independent outputs, each with a rated current of 3 A at up to 60 °C.
• Adjustable output current from 0.5 A to 3 A per channel.
• Response delay of maximum 5 seconds, with switch-off characteristics for overcurrent and short-circuit conditions.
• Three-color LED per output for clear status indication: green for output switched through, yellow for manual off, red for overcurrent shutdown.
• Common signaling contact (changeover contact, rated 0.1 A/24 V DC).
• Remote reset function via a non-electrically isolated 24 V input (signal level "high" at >15 V).
• Galvanic isolation between input and output at switch-off: No.
• Efficiency of 97%, with typical power loss of 9 W at rated output.
• Input voltage range: 22 ... 30 V DC, with overvoltage capability up to 35 V.
• Output voltage follows input voltage minus approximately 0.2 V.
• IP20 protection class, suitable for enclosure mounting.
• Operating temperature range: -25 ... +60 °C with natural convection.
• Dimensions: 72 × 80 × 72 mm (W × H × D), net weight 0.2 kg.
• Mounting on DIN rail EN 60715 35x7.5/15.

One distinctive spec is the ability to set the response threshold individually for each output. This allows engineers to match the module's protection to the exact load characteristics, preventing nuisance tripping while ensuring fast fault clearance.

Applications and Use Cases for the 6EP1961-2BA11

In a typical PLC cabinet, the module distributes power to multiple field devices, such as sensors, actuators, and controllers. If a short circuit occurs on one branch, the affected output switches off within milliseconds, while the other channels continue to supply power. This selective behavior minimizes downtime and helps maintain production continuity.

Furthermore, the adjustable threshold allows coordination with upstream protective devices, ensuring that the closest breaker to the fault operates first. This selectivity is crucial in large installations where multiple levels of protection exist.

Installation and Setup of the 6EP1961-2BA11

Mounting the 6EP1961-2BA11 is straightforward: snap it onto a standard DIN rail EN 60715 35x7.5/15. Ensure adequate spacing for ventilation: keep at least 50 mm free above and below the module. The module can be lined up side by side with other SITOP components, with zero clearance required on the left and right.

Electrical connections are made via screw terminals. The input accepts +24 V and 0 V connections, with two terminals each for 0.5 ... 16 mm² (for +24 V) and 0.5 ... 4 mm² (for 0 V). Each output has one terminal for 0.5 ... 4 mm². The remote reset input and signaling contact also use screw terminals for 0.5 ... 4 mm². For sequential connection of outputs, a DIP switch allows setting a delay time of 25 ms, 100 ms, or a "load optimized" mode, which is useful when starting capacitive loads.

Before wiring, verify that the input voltage is within the 22 ... 30 V DC range and that the total input current does not exceed 12 A. Set the threshold for each output using the potentiometer, and test the response by simulating an overload.

Maintenance and Reliability of the 6EP1961-2BA11

With an MTBF of 755,915 hours at 40 °C, the module offers high reliability. Regular inspection of the LED indicators can reveal channel status at a glance. Since the module has no user-serviceable parts, maintenance is limited to periodic checks of terminal tightness and ensuring that ambient temperature stays within -25 ... +60 °C. The module is designed for natural convection, so avoid obstructing airflow.

The high efficiency of 97% reduces heat generation, contributing to a longer service life and lower energy costs. The module also has an Environmental Product Declaration, with a total Global Warming Potential of 290.7 kg CO2 eq, reflecting Siemens' commitment to sustainability.

Compatibility and Integration

The 6EP1961-2BA11 is part of the SITOP PSE200U family and is designed to work with Siemens SITOP power supplies. It can be used in any 24 V DC system that meets the input requirements. The common signaling contact can be wired to a PLC input to provide remote monitoring of all four channels. The remote reset input allows automatic or manual resetting of tripped outputs without opening the panel.

For marine applications, the module holds approvals from ABS and DNV, making it suitable for shipboard installations. It also carries CE, UL, and EAC approvals, and a CB certificate, ensuring broad acceptance in global markets.

Troubleshooting and Common Issues with the 6EP1961-2BA11

If an output trips, the red LED indicates an overcurrent condition. Check the load for a short circuit or excessive current draw. The module switches off after approximately 5 seconds for currents between 1.0 and 1.5 times the set value, or after about 100 ms for currents above 1.5 times the set value. If the input voltage drops below 20 V, the module performs an immediate switch-off in about 0.5 ms.

If an output does not reset, verify that the remote reset signal is high (>15 V) and that the input voltage is above 20 V. The yellow LED indicates that the output was switched off manually. Use the remote reset function to re-enable the output.

For persistent issues, consult the Siemens manual or contact AutoDCSTech for technical support.

Product Support and Availability

The Siemens 6EP1961-2BA11 is available from AutoDCSTech. Contact our team for pricing and lead times. We offer fast worldwide shipping and dedicated technical support to help you integrate this module into your system.