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The ABB 1VCR004290G0005 Under Voltage Release – MU is a protection and control accessory used with compatible ABB circuit-breaker equipment. It monitors the control voltage supplied to the release mechanism and affects the breaker operating state when that voltage falls below the required level.
In practical switchgear service, an undervoltage release is commonly used where a circuit breaker must not remain closed after loss or significant reduction of its control supply. For example, in a motor control center, distribution panel, or industrial switchboard, the release can initiate the breaker opening function when the associated control circuit is de-energized.
The 1VCR004290G0005 is therefore part of the breaker operating mechanism rather than a standalone protective relay. Correct identification of the compatible breaker, release arrangement, control-voltage circuit, and mechanical installation is important when replacing this component.
| Parameter | Specification |
|---|---|
| Product | ABB 1VCR004290G0005 Under Voltage Release – MU |
| Product Type | Under Voltage Release |
| Model | 1VCR004290G0005 |
| System Role | Circuit-breaker undervoltage release accessory |
| Main Function | Monitors control voltage and affects breaker operation |
| Application | Industrial switchgear and circuit-breaker systems |
| Component Type | Electrical and mechanical breaker accessory |
| Dimensions | 160 × 55 × 110 mm |
| Weight | 0.83 kg |
The undervoltage release is connected to the circuit breaker’s control-voltage circuit. When the required control voltage is present, the release remains in its normal operating condition. If the control voltage falls sufficiently, the release mechanism changes state and causes the associated breaker to trip or prevents the breaker from being closed, depending on the breaker configuration.
In an actual switchboard, this function can be tied to an external control circuit such as an emergency-stop chain, control transformer, interlocking circuit, or other voltage-dependent protection logic. The release therefore provides a direct relationship between the condition of the control supply and the mechanical state of the circuit breaker.
When troubleshooting, a breaker that will not close should not automatically be attributed to a defective release. Loss of control voltage, incorrect wiring, an active interlock, a mechanical problem in the breaker, or another release accessory can produce similar symptoms.
| System Element | Function |
|---|---|
| ABB Circuit Breaker | Opens and closes the protected power circuit |
| 1VCR004290G0005 Under Voltage Release | Monitors the associated control voltage and affects breaker operation |
| Control Power Supply | Supplies voltage to the release and other breaker control circuits |
| Trip and Closing Mechanism | Converts electrical release commands into breaker mechanical movement |
| Auxiliary Contacts | Provide breaker status information to control and monitoring circuits |
| Protection and Control System | Provides protection, interlocking, and operating commands |
| Electrical Load | Receives power when the breaker is in the appropriate operating state |
The 1VCR004290G0005 operates at the interface between the breaker control circuit and its mechanical operating mechanism. A problem in this component or its control-voltage circuit can directly affect breaker closing or opening behavior.
| Application | Typical Use |
|---|---|
| Industrial Switchgear | Undervoltage-dependent breaker operation in distribution assemblies |
| Motor Control Centers | Opening or preventing closure of breakers when control voltage is lost |
| Power Distribution Panels | Integration of undervoltage functionality into compatible circuit breakers |
| Industrial Control Cabinets | Linking breaker operation to control-power conditions |
| Electrical Protection Systems | Supporting voltage-dependent breaker trip and closing logic |
| Switchgear Maintenance | Replacement of worn or defective undervoltage release assemblies |
| Component | Function |
|---|---|
| Compatible ABB Circuit Breaker | Provides the main switching and protection function |
| Circuit Breaker Operating Mechanism | Converts electrical commands into mechanical breaker movement |
| Control Power Supply | Supplies the operating voltage required by the release and control circuit |
| Closing Release | Controls electrically initiated breaker closing where fitted |
| Shunt Trip Release | Provides an electrically initiated breaker opening function where fitted |
| Auxiliary Contacts | Communicate breaker status to external control circuits |
| Protection Relay | Detects electrical faults and issues protection commands |
| Model / Product Family | Product Type | Typical Application |
|---|---|---|
| ABB 1VCR004290G0005 | Under Voltage Release – MU | Undervoltage control of compatible circuit breakers |
| ABB Circuit Breaker Release Units | Breaker Accessory | Electrical trip and closing functions |
| ABB Shunt Trip Releases | Circuit Breaker Accessory | Remote electrical breaker opening |
| ABB Closing Releases | Circuit Breaker Accessory | Electrically controlled breaker closing |
| ABB Auxiliary Contact Assemblies | Circuit Breaker Accessory | Breaker status feedback and control-system integration |
| ABB Circuit Breaker Operating Mechanisms | Mechanical Breaker Accessory | Mechanical switching and release operation |
It is an undervoltage release accessory for compatible ABB circuit breakers. It monitors the associated control voltage and can affect the breaker operating state when the required voltage condition is no longer maintained.
A missing or insufficient control voltage is one possible cause. The closing circuit, mechanical interlocks, other breaker releases, auxiliary contacts, and the breaker mechanism should also be checked before identifying the undervoltage release as the fault.
No. The release is an accessory that integrates with a specific breaker mechanism. The complete breaker configuration should be verified before selecting and installing a replacement.
Check the control-voltage circuit, release installation, breaker mechanical operation, and expected response to the relevant voltage condition. The breaker should be tested under controlled conditions before returning the switchgear to normal service.