GB/T 24612.2-2009Requirements for electrical safety in the workplace - Part 2: Safety measure of operation on power off (English PDF)

3.1 Lockout

Also called lockup, a safety measure to lock a disconnecting means with power or energy disconnected in case of other persons connecting the power or energy (like opening the valve).

3.2 Tagout

Also called tagging, a safety measure to hang the corresponding caution or warning board (like "No switch-on and someone is at work") on a disconnecting means with power or energy disconnected to warn the other persons not to connect the power or energy.

3.3 Electrical diagram

A graphic form to express the information, mainly through the graphical symbols to express electrical items and the relation among them.

3.4 Disconnecting means

An equipment or a group of equipment capable of disconnecting the circuit of the power supply connecting the equipment(s).

5.3.2 Control mode

Three control modes for the power hazard are permitted. lockout and tagout controlled independently by the professional personnel, simple electrical lockout and tagout and complex electrical lockout and tagout (see 5.4). The first and second lockout and tagout operation shall be in the charge of the professional personnel. The third lockout and tagout operation shall be in the charge of the designated persons.

5.3.3 Checking procedure

The electrical lockout and tagout shall be checked periodically by the professional personnel in terms of at least one lockout and tagout operation in progress and the detail content of the control procedure. The checking procedure is aimed to rectify the control procedure or the understanding defects or mistakes of the personnel.

5.4 Control of Electric Shock Prevention

5.4.1 Control mode of professional personnel working independently

This control mode is permitted when the equipment, disconnected, with exposed conductor or circuit parts available is subject to little daily maintenance, repairing, adjustment, cleaning, checking, debugging and similar works. If the exposed conductor or circuit parts is ensured to be close the disconnected switch, namely in a position where the professional personnel who are conducting the work may see the state of the disconnecting switch clearly and ensured to be safe, the lockout and tagout may not be carried out for the execution of this control mode.

5.4.2 Operating mode of simple lockout and tagout

The modes other than the control mode of professional personnel working independently (see 5.4.1) and complex lockout and tagout mode (see 5.4.3) are regarded to be the operating mode of simple lockout and tagout. It is regarded to be a simple lockout and tagout when the professional personnel work on or nearby the equipment of a group of conductor or circuit parts; for this type of lockout and tagout, the control plan of lockout and tagout procedure is not required to be prepared every time. For every personnel conducting the simple lockout and tagout operation, they shall dismantle the locks and tagout installed by themselves.

5.4.3 Operating mode of complex lockout and tagout

5.4.3.1 The control plan of complex lockout and tagout procedure shall be prepared when one or more conditions below are available.

a) Multiple powers;

b) Multiple departments involved;

c) Operated by multiple procedures;

d) In different positions;

e) Multiple organizations involved;

f) Having different disconnect modes;

g) Having special order.

5.4.3.2 Operation of complex lockout and tagout shall be in the charge of a special personnel.

A professional personnel must be designated to be responsible to control the operation procedure of complex lockout and tagout and ensure all the powers to be under the control of the lockout and tagout; the responsible person shall explain clearly to all the working personnel engaging in the above works.

5.4.3.3 The duties of the responsible person for the operation procedure of complex lockout and tagout The responsible person is permitted to instruct other working personnel to install the lock and tagout or replace other working personnel to install the lock and tagout. The ...