Siemens A6X30139942 Key-Operated Switch
Key Selection Trade-offs for the 3SU1 Series Keylock Body
The A6X30139942 is a key-operated switch body from Siemens' 3SU1 industrial series. Several selection dimensions require deliberate decision-making:
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Key-lock mechanism type: This part uses a CES (Centrally Encoded Safety) key-lock profile. Other catalog entries in the same series include OMR and RONIS profiles — these are mechanically distinct and non-interchangeable. Verify that the CES profile aligns with your key management or access-control procedure before selection.
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Switching position configuration: The title "I>O-II" indicates a three-position selector with key motion from center to right (position II). Catalog alternates show I-O (two-position) and O-I variants. Confirm the required position sequence for the machine function it will command.
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Contact block assembly requirement: The body does not include contacts. The catalog explicitly states it Requires: Contact Block(s). The appropriate Siemens contact block series (such as 3SU1 3SY 3-pole contact blocks) must be ordered separately and assembled before panel mounting.
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Illumination: This body is non-illuminated. If status indication is required at the operator interface, an illuminated variant from the same series must be selected instead — illumination cannot be retrofitted after assembly.
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Panel compatibility: The body fits a 22.3mm round cutout. Confirm that your enclosure or operating panel is prepared for a Siemens 22mm (Type 4X / IP65) rated installation and that the key operator projection is acceptable for the operator's reach envelope.
Specifications
| Parameter | Value |
|---|---|
| Series | 3SU1 |
| Actuator Type | Keylock |
| Compatible Series | Siemens, 22mm |
| Encapsulation | Box |
| Illumination | Non-Illuminated |
| Panel Cutout | 22.3mm (Round) |
| Product Status | Active |
| Requires | Contact Block(s) |
| RoHS Compliance | ROHS3 Compliant |
Similar Catalog Parts
The following parts share the same series, panel cutout, and compatible 22mm Siemens platform. They differ in key-lock profile or switching position; the reader must verify suitability for their application.
| MPN | Actuator Type | Key Profile | Positions | Similarity |
|---|---|---|---|---|
| A6X30139942 | Keylock | CES | I>O-II | — (primary) |
| A6X30139242 | Keylock | OMR | I-O | 0.92 |
| A6X30139642 | Keylock | OMR | O-I | 0.92 |
| A6X30139049 | Keylock | RONIS | O-I | 0.92 |
Why they are similar: All four parts share the same Siemens 3SU1 series, box encapsulation, 22.3mm round panel cutout, and require external contact blocks. The primary distinction is the key-lock profile (CES vs. OMR vs. RONIS) and the available switching positions. Each profile supports a different lock-and-key indexing scheme, so substitution must consider the key management policy for the installation.
FAQ
What does the suffix "I>O-II" indicate for A6X30139942? It describes a three-position key-operated selector: the key is freely removable from center position, can be rotated to position II, and returns to center when released from position I. Confirm this sequence matches the machine interlock sequence you require.
Can this switch body be used without a contact block? No. The catalog entry lists Requires: Contact Block(s). The body is a mechanical operator only; switching contacts must be ordered separately from the Siemens 3SY contact block family for the 3SU1 series.
What is the difference between CES and OMR key profiles in the 3SU1 catalog? Both are mechanical key-lock indexing systems for the 3SU1 key-operated switch family. CES (Centrally Encoded Safety) and OMR (Oliver Mario R./manufacturer-specific code) use different key barrel geometries and indexing, meaning a CES key will not operate an OMR lock body. Selection depends on the keying hierarchy defined for the machine or facility.