According to Section 120.3, lockout/tagout principles include several key principles:

• Rules related to employee involvement
• The actual lockout/tagout procedure
• Rules on controlling all sources of electrical energy
• Ensuring that any electrical circuit interlock operation can’t result in reenergizing the circuit being worked on
• Rules to prevent any electrical control devices from being used as a primary isolating device
• Identification of lockout/tagout devices
• Proper coordination between all parties involved with the lockout/tagout procedure
• Forms of hazardous electrical energy control including both the simple lockout/tagout and the complex lockout/tagout procedures

Section 120.3 outlines comprehensive guidelines for implementing lockout/tagout (LOTO) practices, which are essential for ensuring electrical safety in the workplace. Each element specified within the section aims to address different aspects of the lockout/tagout process, ensuring that all potential electrical hazards are adequately managed during maintenance or repair work. Below is additional information on each key element listed above:

• Rules Related to Employee Involvement

This element emphasizes the importance of involving employees in the development and execution of lockout/tagout procedures. It ensures that the workers who are directly affected by these procedures have a say in how they are formulated and implemented, which can increase compliance and effectiveness.

• The Actual Lockout/Tagout Procedure

This refers to the specific, step-by-step procedures that must be followed to safely de-energize and re-energize equipment. These procedures should be detailed and tailored to each piece of equipment or system, covering all aspects from the initial shutdown to the final removal of lockout/tagout devices.

• Rules on Controlling All Sources of Electrical Energy

Comprehensive control of all sources of electrical energy means ensuring that every source that can potentially energize the equipment is identified and isolated. This includes main power supplies, backup power, capacitive, or inductive stored energy within the system.

• Ensuring That Any Electrical Circuit Interlock Operation Can’t Result in Reenergizing the Circuit Being Worked On

This element prevents accidental re-energization by ensuring that interlocks (which are designed to prevent certain actions unless another action has taken place) do not inadvertently allow the circuit to become energized during maintenance or servicing.

• Rules to Prevent Any Electrical Control Devices from Being Used as a Primary Isolating Device

Electrical control devices such as push buttons, selectors, and other types of switches should not be used as the primary means for de-energizing circuits. These are prone to failure and do not provide a visible means of disconnection. Primary isolation should be achieved using devices that provide a physical break in the circuit.

• Identification of Lockout/Tagout Devices

All lockout/tagout devices used must be clearly identified to show which worker has applied the device and to ensure that they are distinguishable from other devices in use. This prevents accidental removal and ensures clear communication among all personnel involved.

• Proper Coordination Between All Parties Involved with the Lockout/Tagout Procedure

Effective communication and coordination between all parties, including maintenance staff, operators, and supervisors, are crucial for the safe implementation of lockout/tagout procedures. Coordination ensures that everyone is aware of the status of the procedures and any potential changes.

• Forms of Hazardous Electrical Energy Control Including Both the Simple Lockout/Tagout and the Complex Lockout/Tagout Procedures

This element recognizes that different situations may require different levels of control. Simple lockout/tagout might involve locking out a single energy source for straightforward equipment, while complex lockout/tagout could involve multiple energy sources or steps, requiring coordination across different teams or shifts.

Each of these elements plays a vital role in ensuring that lockout/tagout procedures are effective and that workers are protected from electrical hazards. Proper implementation of these elements as outlined in NFPA 70E helps create a safer working environment where the risks associated with electrical energy are well-managed.

Below is a sample of NFPA 70E. For the complete section, see the actual NFPA 70E text at NFPA.ORG. Once there, click on the free access link to NFPA 70E.

120.3 Lockout/Tagout Principles.

(A) Employee Involvement. Each person who could be exposed directly or indirectly to a source of electrical energy shall be involved in the lockout/tagout procedure.

(E) Control Devices. Locks/tags shall be installed only on circuit disconnecting means. Control devices, such as pushbuttons or selector switches, shall not be used as the primary isolating device.

(F) Identification. The lockout/tagout device shall be unique and readily identifiable as a lockout/tagout device.

(H) Forms of Control of Hazardous Electrical Energy. Two forms of hazardous electrical energy control shall be permitted: simple lockout/tagout and complex lockout/tagout [see 120.5]. For the simple lockout/tagout, the qualified person shall be in charge. For the complex lockout/tagout, the person in charge shall have overall responsibility.