GB/T 40437-2021Electrical safety—Guidelines for risk early-warning (English PDF)

3.1 Early-warning

The general term for activities that monitor and predict possible abnormal states or emergencies and issue alarms based on the regularity and experience of electrical safety risks, as well as the possible residual risks of electrical equipment and systems.

3.2 Electrical safety risk early-warning system

5.1 Principles for determining early-warning risk elements

The principles for determining early-warning risk elements include but are not limited to.

- objective;

- related;

- systematic;

- traceable;

- Combination of qualitative and quantitative.

5.2 Sources of early-warning risk elements

Based on historical data (such as hazard and accident records) and electrical safety risk assessment results, according to the principles of early-warning risk elements, the sources include but are not limited to the following.

- Risk elements for electrical equipment and systems.

- Residual risks;

- Risks of failure of protective measures (for example, according to the protective measures taken by the user);

- Risks associated with using the information, such as risks not disclosed in the instructions.

- Risk elements of the environment, such as the effect of changing environmental conditions on personnel and/or equipment.

- Risk elements for personnel, such as moving within a non-moving range, not wearing or not properly wearing protective equipment, equipment that requires professional operation is operated by non-professionals without permission.

- Risk elements of human-machine collaborative operation, such as the accuracy of information transmission.

5.3 Influencing factors for early-warning risk elements

Early-warning risk elements are affected by the following factors.

- Severity of the injury caused by the early-warning risk element.

- Possibility that the early-warning risk element may cause injuries.

- Potential for exposure of personnel and/or electrical equipment and systems to hazardous situations;

- Probability of occurrence of a hazard;

- Possibility of technology and personnel to avoid or limit injury is affected by factors such as personnel skill level, safety knowledge, experience, and the speed at which injury occurs.

5.4 Description of early-warning risk elements

The description of early-warning risk elements includes the description of basic information, trigger information and injury information, including.

- Basic information is the information description of the normal state of electrical equipment and systems, environment, and personnel related to electrical safety. It may include. classification, use, mobility, operation of electrical equipment; environmental information such as altitude, temperature and humidity, atmospheric pressure, rain and snow; personnel attributes such as professionals, trained personnel (electrical) or non-professionals;

- Trigger information is the information description of the trigger factors for the development of early-warning risk elements into electrical safety hazards. It may include. unsafe state of electrical equipment and systems, unsafe state of the environment, unsafe behavior and state of personnel;

- Injury information is the description of the electrical safety hazards that may be caused by early-warning risk elements. It may include. injury type, injury outcome, injury nature, injury severity.

6.1 General principle

The monitoring of early-warning risk elements shall be subject to the overall arrangement of the early-warning system.

- Facilities and environment;

- Choice of monitoring method;

- Data identification rules;

- Quality control.

The factors affecting the stability of monitoring data include, but are not limited to.

- Monitoring data error deviation;

- Monitoring data identification deviation;

- Discreteness of monitoring data.

7.1 General principles

According to the risk index determination method specified in GB/T 34924-2017, according to the following priority principles, determine the rating of early-warning.

a) People-oriented. The rating of early-warning risk elements causing personal injury is the highest;

b) The rating of early-warning risk elements causing property damage is the second;

c) The third is the early-warning risk elements for process failures;

d) The last is equipment failures.

7.2 Determination of risk index

7.2.1 Analyze the influencing factors for risk index, including.

a) Degree of damage (indicated by S).

1) Slight (normally reversible or repairable in a short period of time), represented by S1;

2) High (normally reversible or repairable in the long term), represented by S2;

3) Severe (normally irreversible or irreparable) or dead, represented by S3.

b) Severity of damage (denoted by F).

8.1 General principles

- Being targeted;

- Being timely;

- Being safe;

- Being stable;

- Being reliable;

- Being economic and reasonable.

8.2 Classification of early-warning measures

According to the law and experience of electrical safety risk occurrence, prevention (permanent) measures shall be taken for predictable situations. Emergency measures shall be taken for emergencies. Prevention (permanent) measures include, but are not limited to.

- The auditory, visual and tactile measures set on electrical equipment and systems can be coded in accordance with the provisions of GB/T 4025-2010.

- The auditory and visual measures at the application site may include. indicator lights, graphic symbols, safety signs, safety slogans;

- Personnel protection measures, personnel training;

- Monitoring measures for environmental factors;

- Emergency plans.

Emergency measures include but are not limited to.

- Intervention measures.

- Manual intervention, such as eliminating the danger of the equipment through operation, actively leaving the dangerous area, reducing the time of exposure to the dangerous area;

- Device intervention, such as automatically stopping work.

- Information dissemination measures.

- Audible signaling measures, such as voice warnings, alarm warnings;

- Visual signal measures, which may include visual warning measures, visual hazard measures, visual emergency measures, such as text warning, light warning.

- Evacuation measures.

8.3 Release of early-warning measures

When the early-warning risk elements cannot form a closed loop, such as the evacuation of personnel, the removal of dangerous conditions of equipment and other dangerous situations, or the danger does not reach the early-warning level, the early-warning measures can be released in time.

9.1 Overview

According to the electrical safety risk assessment method specified in GB/T 34924-2017, conduct whole-process risk assessment for electrical safety risk early-warning, including early-warning risk elements, monitoring of early-warning risk elements, rating of early-warning, and early-warning measures.

This document only proposes the methods and contents covered by the risk assessment of the whole process of the early-warning system. Specific evaluation details may be specified in the product standard.

9.2 Evaluation of early-warning risk elements

The assessment contents of early-warning risk elements include but are not limited to.

- Objectivity, relevance, systematicness and traceability of early-warning risk elements;

- Safety of determination process of early-warning risk elements;

- Risk assessment of the early-warning risk elements that need to be re-selected will not generate new risk elements.

9.3 Assessment of monitoring of early-warning risk elements

The assessment contents of monitoring of early-warning risk elements include but are not limited to.

- Completeness of the information of the monitoring object;

- Security of the information data conversion process of the monitoring object;

- Accuracy and stability of monitoring data; […]