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Safety guides and audits to make your job as a safety professional easier

Electrical Systems and Machine Guarding

Energy Isolation

Inspection of effective energy isolation is important to ensure that potential energy sources are labeled and that proper energy isolation methods are being utilized. For more information see: 29CFR1910.147, American Petroleum Institute (API) Recommended Practice 54, and the IADC Health, Safety and Environmental Reference Guide.

Assess if energy isolation equipment (i.e. locks, restraints, and blocks) are being used, worn, and correctly labeled. Rig equipment should be assessed to determine if the proper energy isolation methods are being used.

Additionally, postings, labeling, and warnings should be checked to make sure they are accurate and visible.

Energy Isolation (Continued)

lockout tagout


You will need to list the name and location of each piece of equipment with electrical, stored, chemical injection, or mechanical energy.

Electrical Sources

Check that electrical energy sources are identified by labeling. Lock out devices should be available for each type of power disconnect on the rig. In addition, written instructions should be available for completing lock out on each piece of rig equipment.

Multiple Electrical Sources

Check that the different types of power sources on equipment with multiple power sources are labeled on the machine. Many rig components may have multiple energy sources associated with their operation and maintenance. Traction motors may have a control circuit as well as Direct Current (DC) and Alternating Current (AC) power feeds.

Auto Start Equipment

Check that equipment that starts automatically or, that can be started from a remote location, is properly guarded and clearly marked. Air compressors, hydraulic power units and charge pumps are examples of equipment that can be started remotely or automatically should all be labeled.

Energy Isolation (Continued)

Stored Energy

Check that equipment that contains stored energy is labeled. Some hydraulic equipment may have internal accumulators or reservoirs where pressure is stored. Refer to manufacturer’s documentation and ensure that labeling on the equipment is complete and visible. Mechanical equipment may have some type of internal “pre-load” such as springs or tension devices that may release energy if the unit is disassembled without the proper precautions. Examples include: valve actuators, mechanical well logging equipment, retractable cable devices, and crown saver devices.

Chemical Injection Systems

Check that chemical injection systems are identified and are included in the isolation procedure for any attached equipment. Some rigs may have chemical injection systems that feed mud products or chemicals directly into the circulating system. Chemical tanks that gravity feed into the mud tanks should also be identified for isolation in the tank cleaning procedure.

Mechanical Energy

Traveling blocks, sheaves hung in the derrick, and pipe tongs are examples of energy hanging in the derrick.

Inventory overhead equipment to identify which must be restrained for maintenance or secondary fall protection. Check that cables or other hang off devices required are adequate for the load they are expected to support. Overhead sheaves must be designed by the manufacturer for overhead use. When making changes, such as adding a rental top drive, the traveling block hang-off device must be analyzed to ensure it is adequate to hold the additional weight.

Electrical Systems

lockout tagout

It’s important to inspect all aspects of a site’s electrical system and equipment to ensure that electrical systems are well documented and include appropriate safety controls. For more information see: 29CFR1910.305, and American Petroleum Institute (API) Recommended Practice 54, 500 and 505.

Electrical systems inspections are usually visual only. An approved electrician is the only person who should modify or repair electrical equipment. Do not “try out” circuits or switches, and always de-energize electrical equipment before performing maintenance work.


List each area of the rig for inspection.

Area Type (Classification)


Inspect classified areas on the rig to ensure that equipment and electrical installation meet the requirements of the designated classification.

There should be no non-classified equipment in the area and all cables and conduit should be in good condition.

Check for crossover plugs to get from classified outlets to non-classified equipment or cords. These devices should not be used when classified areas are active.

Cords and Cables

Inspect all cable or cord installations to ensure they are correctly routed and are protected from other rig activities that may damage them.

Cords should not be run up stairs or ladders or present a tripping hazard for employees. Cords and cables should not be run in rig ditches or across the ground unprotected.

Cable trays should be organized and free from debris and not be used for storage shelves.

Extension cords should be used for temporary power source only. Extension cords should be inspected before each use and cords that have cuts or crushed protective coating should be removed from service and destroyed.

Conduit and Boxes

lockout tagout

All fixed conduit should be securely attached and undamaged. Check ends to ensure they have not been pulled loose from panels or junction boxes. Make sure box covers are properly installed and water-tight.

All unused outlets or plugs should be covered. Electrical conduit and wire racks should not be used to hang or store materials.

Panels and Switches

Electrical panels and switches should not be blocked and must be readily accessible. Panels should not be used for storage shelves or hangers.

Doors should be kept closed and latched except when actively working switches and breakers.

Breaker panels should have the faceplates securely installed and no wiring should be exposed to employees operating breakers or switches. Switches should be clearly labeled.


Ground Fault Circuit Interrupters

Ground Fault Circuit Interrupters, or GFCI’s should be used for all portable or temporary power tools used on the rig. If GFCI breakers are not installed in breaker panels, portable units should be provided that can be placed in line to protect employees from ground shocks when using portable power tools.


The rig and its components must be grounded and bonded to ensure a clear path to ground in the event of a short circuit. The ground rods must be installed before starting power generation equipment and not detached until generators are shut down. All buildings and electrical equipment must be bonded to the ground system.

Machine Guarding

be careful

It’s critical to inspect all machine guards to ensure that mechanical installations around the rig are properly guarded and maintained to eliminate injuries to employees. For more information see: 29CFR1910.212- 219, and American Petroleum Institute (API) Recommended Practice 54.

This inspection should be visual only. An approved electrician is the only person who should modify or repair electrical equipment. Always de-energize electrical equipment before performing maintenance work.


List each area of the rig inspected.

Centrifugal Pumps

Check the electric motor for broken or missing fan guards.

Inspect the coupling area for potential exposure to rotating parts. Coupling guards should be secure and not move when operating. The stuffing box area and shaft should be smooth and free of burrs that could entangle gloves or other clothing.

Agitators and Mud Mixers

Inspect for potential contact. Pay close attention to the area above tank gratings and walkways where hoses or electrical cords could become tangled in couplings. Check chemical mixers or other rotating equipment that may be used for adding chemicals to the mud system for potential contact.

Machine Guarding (Continued)

machine guarding

Augers and Conveyors

Cuttings augers and conveyors present unique guarding challenges to protect employees from these powerful machines. Gratings and guards for this type of equipment should be securely fastened. Inspection hatches and cleanouts should be secured and lockout procedures should apply to any service or inspections that require removal or opening of hatches or guards.

Belt Guards

Inspect all belt guards to ensure that they are installed properly and that all bolts and braces are in place and tight. Make sure that there are no worn spots on the guard that would indicate rubbing or chaffing by moving equipment. If guards make noise or if it shows signs of movement, the machine should be shut down and the guard must be repaired immediately.

Machine Guarding (Continued)

Winches and Cables

Nip points are created by a cable being wrapped on a drum. Areas where employees may come in contact with the cable should be protected with a guard that only allows room for the cable to enter.

Level wind devices for hoist winches should have a handle that prevents the operator from placing his hand directly on the cable. Sheave guards on the crown block and traveling block should be inspected for abnormal wear and secure attachment to prevent dropped objects.

Labeling and Signs

Equipment that starts automatically or is controlled remotely should have a sign clearly visible that identifies how the equipment is energized. Warning signs should be posted to ensure employees follow proper energy isolation protocol when servicing equipment.

Exclusion Zones

Areas that cannot be effectively guarded should be closed off as an exclusion zone while in operation. For example, under the rotary table during drilling operations and around automated pipe handling systems.

OSHA's Machine Guarding ETool

Oregon OSHA's Machine Safeguarding and the Point of Operation: A Guide For Finding Solutions to Machine Hazards.


Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. When inspecting the company's lockout/tagout program, verify that lock out devices are available for each type of _____ on the rig.

2. Each of the following pieces of equipment should be listed in the energy isolation program, except _____.

3. While you are conducting an inspection you should make sure electrical panels and switches are _____ and readily accessible.

4. Which of the following must be installed on a rig prior to starting power generation equipment and not detached until generators are shut down?

5. Areas on a rig that cannot be effectively guarded should be closed off as an _____ while in operation.

Have a great day!

Important! You will receive an "error" message unless all questions are answered.