SIEMENS 3RV2902-4AP0 Undervoltage Release

1. Product Name

SIEMENS 3RV2902-4AP0 Undervoltage Release

2. Product Introduction

The SIEMENS 3RV2902-4AP0 is an undervoltage release accessory designed for use with Siemens SIRIUS 3RV2 motor protection circuit breakers (MPCBs). Its primary function is to automatically open (trip) the connected circuit breaker when the supply voltage drops below a preset threshold, thereby providing protection for downstream equipment, such as ‌SIEMENS MOTOR‌ drives and control systems, from potential damage or unsafe operation under low-voltage conditions.

3. Product Description

The SIEMENS 3RV2902-4AP0 is an essential add-on module from the SIRIUS 3RV accessory range, engineered to enhance the safety and functionality of motor protection assemblies. Designed for use with 3RV2 series circuit breakers in sizes S00, S0, and S2 , this undervoltage release acts as a voltage-sensitive trip device. It continuously monitors the line voltage connected to its auxiliary circuit. If the voltage falls below a specified value (rated for AC 230V/50Hz and AC 240V/60Hz ), the release triggers and mechanically opens the main contacts of the connected motor protection circuit breaker, isolating the circuit. This function prevents ‌SIEMENS MOTOR‌ systems and other sensitive loads from starting or operating under under-voltage conditions, which can lead to motor overheating, reduced torque, or component failure. By ensuring disconnection during a voltage drop or loss of power, the device helps protect equipment from subsequent issues when power returns, such as unexpected simultaneous restart of multiple motors. The release features a snap-on mounting mechanism for quick and secure attachment to compatible breakers and includes ring cable lug connections for reliable wiring. With its compact design (90mm in height and 19mm in depth ), it integrates seamlessly into control panels, contributing to a robust protection scheme for ‌SIEMENS MOTOR‌ applications, complementing the overload and short-circuit protection offered by the main breaker. It carries approvals such as CE, UL, and CSA ^.

4. Product Model

5. Product Advantages

• ‌Enhanced System Protection:‌ Prevents motors and equipment from operating under potentially damaging undervoltage conditions, safeguarding ‌SIEMENS MOTOR‌ drives from overheating and stress.

• ‌Safety and Process Control:‌ Ensures that circuits remain open when voltage is too low or absent, preventing unexpected automatic restarts upon power restoration, which enhances personnel safety and process control.

• ‌Easy Installation:‌ Features a snap-on mounting design for quick and straightforward attachment to compatible SIRIUS 3RV2 circuit breakers, reducing installation time and effort.

• ‌Compact and Integrated Design:‌ Its small footprint allows for space-saving integration within control cabinet layouts without significantly increasing panel size.

• ‌Versatile Compatibility:‌ Specifically designed for use with 3RV2 circuit breakers of sizes S00, S0, and S2 , making it a flexible accessory for expanding the functionality of existing motor protection setups.

• ‌Reliable Performance and Certification:‌ Operates reliably under specified ambient temperatures and holds major international approvals (CE, UL, CSA) ^, ensuring compliance with global standards.

6. Homepage Link & Website Insights

‌Homepage Link:‌ www.wheat-auto.com

‌Website Insights:‌
Based on the  provided for the homepage of www.wheat-auto.com, this site belongs to ‌Changzhou Wheat Automation Technology CO., LTD‌. The company describes itself as ‌"a high-tech company engaged in electronic products"‌ established in May 2012. The site's structure and content reveal key aspects of its business model:

• ‌Business Nature:‌ It positions itself as a  (foreign trade independent website)‌, indicating its primary focus is on international B2B trade.

• ‌Operations:‌ The presence of a ‌"Request a Quotation"‌ page as a prominent call-to-action, along with standard corporate sections like "Brand," "Applications," and "Support," strongly suggests the company operates as a ‌distributor, supplier, or solutions provider in the industrial automation sector‌. Its core activity likely involves sourcing electronic and automation components (which could include Siemens products like accessories and circuit breakers) and supplying them to industrial clients worldwide.

• ‌Platform Function:‌ The website appears to function more as a ‌corporate portal and lead-generation tool‌ than a detailed e-commerce catalog. Its purpose is to introduce the company's capabilities, attract business inquiries, and facilitate direct contact and quotation requests from potential customers, rather than providing in-depth technical specifications for specific part numbers.

7. Usage Scenarios 

The SIEMENS 3RV2902-4AP0 undervoltage release is deployed in scenarios where undervoltage protection for motor circuits is critical:

• ‌Motor Control Centers (MCCs):‌ Installed on 3RV2 MPCBs protecting ‌SIEMENS MOTOR‌ drives in pumps, fans, and compressors to prevent auto-restart after a power dip, enhancing safety and equipment protection.

• ‌Critical Process Lines:‌ In manufacturing or processing plants where an unexpected simultaneous restart of multiple motors after a voltage sag could damage equipment or disrupt the process.

• ‌Safety-Critical Applications:‌ In systems where machinery must remain off until nominal voltage is stably restored to ensure operator safety, such as on conveyor lines or large machine tools.

• ‌Energy Management Systems:‌ As part of a load-shedding or priority shutdown scheme during low grid voltage conditions to protect sensitive motors and other vital equipment.

• ‌Building Automation:‌ Used in HVAC control panels to safeguard large compressor or fan motors from damage due to prolonged undervoltage operation.