Siemens 3SB3921-0BK Lockout 2-position Selector Switch

Product Description

The SIEMENS 3SB3921-0BK is a lockout accessory designed for 2-position selector switches. It physically prevents the switch from being rotated or actuated, providing a reliable means of locking out control circuits during maintenance, servicing, or energy isolation procedures. Electricians and industrial maintenance technicians install this device as part of lockout/tagout (LOTO) programs to meet OSHA and NFPA 70E requirements. The unit is compact, measuring 0.618 x 0.618 x 0.311 inches, and weighs 0.066 pounds, making it straightforward to add to an existing panel or control station without significant rework.

This lockout is suited for industrial control panels, machine control stations, and process equipment where 2-position selector switches are used to control motors, circuits, or equipment. It is used in both light industrial and heavy manufacturing environments where energy isolation is required before service work begins. Installation is typically performed by licensed electricians or qualified industrial maintenance personnel as part of a documented LOTO procedure.

Key Features

• Designed specifically for 2-position selector switches in the SIEMENS 3SB series
• Enables lockout/tagout (LOTO) compliance on control station selector switches
• Compact form factor at 0.618 x 0.618 x 0.311 inches for easy panel integration
• Lightweight at 0.066 pounds for minimal added load on mounting surfaces
• Prevents unintended or unauthorized switch actuation during service

Compatibility

Designed as an OEM-style lockout accessory for 2-position selector switches in the SIEMENS 3SB series control device family.

Installation Notes

Installation is performed by a licensed electrician or qualified maintenance technician. De-energize and lock out the affected control panel or machine before installing or removing this lockout device. Follow your facility LOTO program and applicable requirements under NFPA 70E and OSHA 29 CFR 1910.147. Do not use this accessory as the sole means of energy isolation for high-voltage or high-energy circuits without a complete LOTO procedure in place.

Technical Specifications

• Length: 0.618 inches
• Width: 0.618 inches
• Height: 0.311 inches
• Weight: 0.066 pounds
• UPC: 75455465489

Standard Information

• Brand: SIEMENS
• Manufacturer Part Number: 3SB3921-0BK