ABB 1SBN030100R1000 VM5-1 Mechanical Interlock Unit for AX Contactors

The ABB 1SBN030100R1000 is a VM5-1 mechanical interlock unit designed for use with compatible ABB contactors in motor protection and control applications. This component belongs to the ABB range of accessories for low-voltage contactors and provides a mechanical interlocking function between two contactors installed in a horizontal arrangement. Its main purpose is to prevent the two mechanically linked contactors from being closed simultaneously.

Mechanical interlocking is an important function in control circuits where two contactors represent mutually exclusive operating states. Typical examples include forward and reverse motor control, changeover arrangements, and other applications in which two contactors must not be mechanically engaged at the same time. The VM5-1 provides this interlocking function directly between compatible contactors without being a separate control relay or electronic monitoring device.

Product Identification

The product identification for this component is ABB 1SBN030100R1000, with the extended type designation VM5-1. ABB documentation lists the component within the mechanical interlock accessories for contactors. The product is specifically identified as a horizontal mechanical interlock unit. This designation distinguishes it from the related VE5-1 version, which combines mechanical interlocking with electrical auxiliary contacts.

Mechanical Interlocking Function

The VM5-1 is designed to work between two compatible horizontally mounted contactors. When the contactors are mechanically connected through the interlock unit, movement of one contactor mechanism restricts the operation of the other. This arrangement creates a physical interlocking relationship and helps ensure that both contactors cannot occupy their closed position simultaneously.

This function is particularly useful in motor control circuits where two different operating commands must remain mutually exclusive. For example, a reversing starter can use two contactors to control the direction of a three-phase motor. One contactor establishes one phase sequence, while the second contactor establishes the opposite sequence. If both contactors were closed at the same time, the power circuit could be subjected to an incorrect switching condition. A mechanical interlock such as the VM5-1 provides an additional physical barrier against simultaneous contactor closure.

Compatibility with ABB Contactors

Correct compatibility is an important consideration when selecting the 1SBN030100R1000. ABB documentation identifies the VM5-1 for horizontal interlocking arrangements involving compatible A9–A40 and AL9–AL40 contactors. ABB product information also associates the VM5-1 with AX09–AX40 contactors in the AX contactor family.

The interlock is therefore selected according to the contactor frame and mounting arrangement rather than by electrical coil voltage. The VM5-1 itself is a mechanical accessory, so its primary selection criteria are the physical contactor family, contactor size, and required mounting configuration. The contactors used with the interlock should be checked against the applicable ABB product documentation before installation.

VM5-1 Compared with VE5-1

The ABB 1SBN030100R1000 VM5-1 should not be confused with the related 1SBN030110R1000 VE5-1. Both belong to the same family of horizontal interlocking accessories, but their functions are different.

The VM5-1 is a mechanical interlock unit. Its function is based on the physical relationship between the two contactors. The VE5-1, by comparison, combines mechanical interlocking with electrical interlocking through two normally closed auxiliary contacts. Therefore, when a control circuit requires only the mechanical interlocking arrangement, the VM5-1 is the relevant product designation. When electrical auxiliary interlocking is also required, the corresponding electrical-mechanical interlock model should be considered.

Installation Arrangement

The 1SBN030100R1000 is intended for a horizontal arrangement between two compatible contactors. The contactors are positioned so that the mechanical interlock can engage with their operating mechanisms. Proper physical alignment is important because the interlock must move together with the contactor mechanisms during operation.

During installation, the contactor types should first be confirmed against the ABB compatibility information for VM5-1. The mechanical mounting arrangement should then be checked to ensure that the two contactors are positioned correctly. Rail mounting or mounting plate arrangements may depend on the selected contactor assembly and installation design, so the supporting mounting hardware should be considered separately when preparing the control cabinet layout.

Application in Motor Control Systems

Mechanical interlocks are commonly used in motor control systems that require two operating states to remain mutually exclusive. A typical example is a forward-reverse motor starter. In this configuration, one contactor is assigned to the forward direction and another contactor to the reverse direction. The mechanical interlock connects the two contactors and prevents the mechanisms from simultaneously reaching the closed position.

The same principle can be applied to other switching arrangements where two contactors control different circuit paths. The VM5-1 is therefore a small component with an important mechanical safety function within a larger low-voltage control assembly. Its use is determined by the contactor arrangement and the control system design rather than by the power rating of the accessory itself.

Technical Characteristics

ABB identifies 1SBN030100R1000 as the VM5-1 mechanical interlock unit. The component is intended for horizontal mounting and has a compact mechanical construction suitable for installation with compatible ABB contactors. Public ABB product information lists a single-piece package quantity and an approximate unit weight of 0.066 kg.

The component is associated with ABB contactors including A9, A12, A16, A26, A30 and A40, as well as corresponding AL and AX contactor ranges within the specified compatibility limits. The precise contactor combination should always be checked against the applicable ABB selection tables because mechanical compatibility depends on the contactor type and mounting configuration.

Selection Considerations

When selecting an ABB 1SBN030100R1000, the first consideration is the contactor model. The two contactors must belong to a compatible range covered by the VM5-1 mechanical interlock. The second consideration is the mounting direction. The VM5-1 is designed for horizontal interlocking arrangements, so it should not be treated as a universal accessory for every contactor configuration.

The required function should also be considered. If the control system needs only physical mechanical interlocking, VM5-1 is the appropriate type within this accessory family. If the application also requires electrical auxiliary contacts for control-circuit interlocking, an electrical-mechanical interlock such as the VE5-1 may be more suitable.

Identification and Maintenance

For equipment documentation and spare-part identification, the complete ordering code 1SBN030100R1000 should be retained together with the VM5-1 type designation. This is useful when identifying components in control cabinets containing multiple contactors and accessories with similar physical appearances.

During maintenance, the mechanical movement of the contactors and interlock assembly should be inspected as part of the overall contactor assembly. The interlock should move correctly with the contactor mechanisms and should not obstruct normal mechanical operation. Any replacement should use the correct interlock type corresponding to the contactor combination and mounting arrangement.

Conclusion

ABB 1SBN030100R1000 is the VM5-1 horizontal mechanical interlock unit for compatible ABB contactors. It is designed to establish a physical interlocking relationship between two contactors and prevent simultaneous mechanical closure. The component is associated with ABB A9–A40, AL9–AL40 and AX09–AX40 contactor ranges and is particularly relevant to motor control arrangements where two switching states must remain mutually exclusive.

With its dedicated mechanical design, compact construction, and defined compatibility with ABB contactor families, the VM5-1 forms an important accessory within ABB low-voltage motor protection and control systems. Correct model identification and contactor compatibility are essential when selecting 1SBN030100R1000 for a particular control cabinet or motor starter configuration.