Siemens 3TY7480-0A Auxiliary Contact Block for 3TF48

The Siemens 3TY7480-0A is an auxiliary contact block designed to snap onto the side of 3TF48 series contactors. It adds one normally open (NO) and one normally closed (NC) contact to the main switching device, expanding its functionality for control circuits and status feedback.

Product Specifications

• Contact configuration: 1 NO + 1 NC (double break)

• Rated thermal current (Ith): 10 A

• Rated insulation voltage (Ui): 690 V

• Switching capacity (AC-15): 230 V / 6 A; 400 V / 3 A

• Switching capacity (DC-13): 24 V / 2.5 A

• Mechanical endurance: 10 million operations

• Electrical endurance: 1 million operations at rated current

Design and Mounting

The 3TY7480-0A features a snap-on mechanism without tools. It attaches to the left or right side of the 3TF48 contactor, extending the overall width by 9mm. The contact block is clearly marked with NO/NC symbols and a mechanical indicator that shows the contact state (green = NO open, red = NO closed).

Terminal and Connection

Screw-type terminals suitable for 1 x 0.5–2.5 mm² solid or stranded wire (with ferrule). Terminal screws are captive and recessed for safety. The block also accepts fork or ring lugs (M3.5). A finger-safe design meets IP20 protection.

Compatibility

Specifically intended for Siemens 3TF48 contactors (e.g., 3TF4800, 3TF4810, 3TF4820). It can also be used on 3TC contactors when an adapter is used. For other contactor frames, refer to 3TY7 series family.

Electrical Life and Reliability

Silver-nickel contacts provide low contact resistance and high resistance to welding. The block is sealed against dust ingress, ensuring reliable operation in polluted industrial environments. No maintenance required under normal conditions.

Typical Applications

Add auxiliary contacts to signal contactor status to a PLC (NO for run indication, NC for overload trip feedback), or to create latching circuits, interlocking sequences, and light indication. It is also used for switching low-power loads such as PLC input modules, pilot lights, and small relays.

Installation Example

To install, snap the block onto the contactor’s side profile until it clicks. Then connect the desired control wires. The block does not require additional grounding. It can be removed with a screwdriver by pressing the release latch.

Standards

IEC 60947-5-1, EN 60947-5-1, UL 508, CSA C22.2 No. 14. CE marked, RoHS compliant. Operating temperature -25°C to +60°C, storage -40°C to +80°C.

Conclusion

The Siemens 3TY7480-0A auxiliary contact block is a practical, durable accessory to expand the signalling capacity of 3TF48 contactors, enhancing flexibility in control panel design.