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G10.3 Worker entry into J-bar sorting system sawmills
G10.4(1) Lockout of multiple devices
G10.4(6) Use of means other than personal locks
G10.10(2) Approval of control system isolating devices
G10.11 Locks not required
Effective August 1999
Section 10.3(1) of the OHS Regulation states "If machinery or equipment is shut down for maintenance, no work may be done until
(a) all parts and attachments have been secured against inadvertent movement,
(b) where the work will expose workers to energy sources, the hazard has been effectively controlled, and
(c) the energy isolating devices have been locked out as required by this Part".
A J-bar sorting system must be locked out, in accordance with Part 10 of the OHS Regulation, before anyone enters into the bin areas, either above or below the lifts. Paragraphs 10.3(1)(a) and 12.15(b) of the OHS Regulation require actions to be taken to ensure the lifts will not move when a worker is present in the bin area. The Board recognizes the following means of securing the lifts against inadvertent movement:
a) lowering the lifts onto positive mechanical stops of adequate size, or onto the bin removal chains. (Safety stops cannot be depended on to withstand the impact of a falling lift, for example, from hydraulic or mechanical failure in suspension system), or
b) another means of restraint when circumstances require entry of a worker into a bin to clear a lumber hang-up which prevents lowering of the lift onto a positive stop.
Blocking and restraining devices must be:
b) maintained as specified by the manufacturer (Section 4.3 applies).
Guarding of the bin removal chain drives is not be required as this is a restricted access area and the system must be locked out before entry is permitted.
Effective August 1999
In some lockout situations, several energy isolating devices located near each other, such as in a motor control center, need to be locked out. One alternative is to use a personal lock to secure each isolating device in the off or safe position. The Board will also accept the running of a cable, bar or chain through the lock points of the devices (once they are in the off or safe position) and securing the cable, bar or chain against removal with a personal lock if the following criteria are met:
There is no limit on the length of cable, bar or chain acceptable or the maximum number of control devices that may be so secured at one time as long as the system ensures equivalent protection to the use of personal locks on each energy isolating device.
Effective August 1999
Section 10.4(6) of the OHS Regulation states
"If the use of a personal lock is not practicable for lockout, another effective means, if approved by the board, may be used in place of a personal lock to secure an energy isolating device in the safe position."
There should be few situations where use of a personal lock will not be practicable.
One example of such a situation would be a school with a circuit breaker panel in a hallway used by students. The panel cover is normally locked, and the maintenance and other personnel who are authorized to access the panel have a key. When maintenance requires a circuit to be locked out, an approach used in the past was to fix a lockable arrangement on the outside of the panel door to allow the worker to switch off the circuit and then lock the panel door shut with a personal lock. This prevented others from accessing other breakers in the panel, and is now prohibited by section 10.5 of the OHS Regulation.
There are devices that can be installed on individual circuit breakers to allow the breaker to be locked out with a personal lock. However, in some cases the personal lock may not allow the panel door to be closed and secured with the panel door lock. This allows unauthorized access to the breakers by students or others. An alternate device acceptable for use in these types of situations would be a "non-reusable seal" that is installed with adequate identification to show who put it on and that it is installed for lockout purposes. All persons with access to the panel must be trained to know the seal is part of a lockout procedure, and is not to be removed by anyone other than the person who installed it. The employer must limit the use of this alternative to situations where a personal lock cannot reasonably be used.
Other areas where the use of a personal lock may not be practicable is to secure blocking, pinning or other devices used to secure equipment in a safe position and/or inoperable. The lockout procedure must be clear on how such devices are to be installed, and require identification of who installed the device. All workers must know such devices are part of lockout and are not to be removed except with the permission of all the persons involved in the lockout.
Issued August 1999; Editorial Revision October 2004; Editorial Revision February 6, 2006; Revised April 27, 2010
Subsection 10.10(2) of the OHS Regulation ("Regulation") states:
Control system isolating devices and the procedures for using them must be approved in writing by the Board, and must be used by workers qualified and authorized to carry out the work.
Section 10.1 of the Regulation states that a:
"control system isolating device" means a device that physically prevents activation of a system used for controlling the operation of machinery or equipment.
Purpose of the guideline
This guideline describes "control system isolating devices" and describes the approval process for these devices and the procedures for using them.
What is a control system isolating device?
Regulation section 10.1 defines a control system isolating device (CSID) as a device that physically prevents activation of a system used for controlling the operation of machinery or equipment. The system in this definition means the control system used for controlling the operation of machinery/equipment where work is being undertaken.
As per the definition, a CSID operates physically to a mode or position to override or disable the control system so that it prevents risk of injury to workers from the movement of the machinery/equipment, or exposure to an energy source.
A switch as a control system isolating device
A switch can be an acceptable CSID if it is rated in the amperage and voltage of the circuit in which it is installed, and is capable of interrupting its rated current at the rated voltage.
The switch is required to be used as per the manufacturer's specification and instruction (e.g., a switch that is rated only for a dry environment cannot be installed in a wet environment, switches used in the hazardous environment need to bear the appropriate approval markings, etc.).
Note that Regulation subsection 10.10(1)(c) specifies that, for machinery and a piece of equipment designed and equipped with effective control system isolating devices, the devices must be locked out before work is done on the machinery or equipment.
An electronic switch (e.g., light curtain, photo eye, and software logic generated output) is not considered to meet the requirements for a CSID since it does not physically prevent activation. IEEE Standard 100 defines a 'physical system' as a part of the real physical world that is directly or indirectly observed or employed.
A dual-channel safety interlock switch as a control system isolating device
A dual-channel safety interlock switch (SIS) that is (i) safety rated (as defined in CSA Z460-05 Control of Hazardous Energy -- Lockout and other methods*), (ii) has a direct opening action, and that (iii) is used in the positive mode of operation can be an acceptable CSID.
*CSA 460-05 states that safety-rated switches are tamper-resistant and mechanically actuated devices with positively driven multiple contacts. Magnetic switches can be safety rated if they are coded and have monitored contacts.
To be acceptable, the SIS needs to be installed as part of a control system that uses safety certified control components meeting design architecture of ISO 13849-1 Safety of Machinery category 3 or 4. These are called control reliable control systems and are described in CSA Z432-04 Safeguarding of Machinery.
The safety related parts of the control system (defined in ISO 13849: 2006 Safety of Machinery, referenced in Guideline G19.36(1)) need to provide acceptable risk-reduction for the task that is being performed under its protection. A SIS installed as above is excluded from fault of non-opening of the contact and/or non-actuation of the switch due to mechanical failure.
How to request written approval
A request under subsection 10.10(2) of the Regulation for approval to use a CSID as an isolation device (i.e., to use control circuit lock-out) is to be submitted in writing to the Regulatory Practices Department. The applicant should conduct risk assessment and the submission should include the following information:
A list of the tasks or activities intended to be done using CSID's.
A description of the hazard(s) which workers will be protected from by using the CSID and procedures.
How the hazards are controlled by installing the control system (or the control system supplied from the manufacturer).
An explanation of why it is not practicable to implement lockout through use of energy isolating devices rather than CSID's.
A description of the proposed control circuit system that will be isolated using the CSID. A schematic diagram of the control circuit system.
The procedures for using the CSID. The procedures should describe in detail (step-by-step) how to perform each task safely while using a CSID (i.e., provide information on how a particular task will be performed using CSID's, not simply how to operate the equipment or machine using the control system). There should also be a procedure for what action the operator/worker is to undertake in case of failure of the control system.
How the control system limits the machine (e.g., when the gate is open the cutter runs at a lower speed etc.)
If SIS's are used as a CSID, provide documentation to show that the safety related parts of the control system use safety certified components and the design architecture meets Category 3 or higher.
After conducting a review of the application, Regulatory Practices will issue a decision letter with respect to approval of the CSID and the associated procedures.
Effective August 1999; Revised March 7, 2011
Section 10.11(a) of the OHS Regulation ("Regulation") states:
The application of a lock is not required under section 10.3 or 10.10 if
(a) the energy isolating device is under the exclusive and immediate control of the worker at all times while working on the machinery or equipment, or ...
Purpose of guideline
The purpose of this guideline is to explain the conditions under which work may be performed on machinery or equipment, using means other than the application of a lock to control various energy sources.
Locks not required
This provision applies only if the energy isolating device is under the exclusive and immediate control of the worker, and it is not reasonably foreseeable that that the machine or equipment could be started inadvertently by the worker performing the work, or by any other worker. It is intended to allow for tool changes on equipment such as a drill press or lathe without requiring lockout through the use of a personal lock.
Given the variation in the types of energy isolating devices that are installed on equipment and machinery, employers need to assess these devices to ensure that they cannot be readily activated in the case of inadvertent movement, such as a worker leaning on or brushing against the energy isolating device. In cases where these energy isolating devices are susceptible to inadvertent activation, this section does not apply. The work must be done as prescribed in accordance with lockout procedures set out in sections 10.3 and 10.4 of the Regulation.
WorkSafeBC will accept that a worker has exclusive and immediate control of the energy isolating device if all of the following criteria have been met: