I wasn't able to find specific documentation on underground electrical distribution switching operations, including required forms, in our current safety knowledge base, but here are industry-standard safety guidelines:

Underground electrical installations require specific safety measures to protect workers from electrical hazards. Here are key aspects of a safety procedure for underground electrical distribution switching operations:

1. Access and Entry:

• Use a ladder or other climbing device to enter and exit a manhole or subsurface vault exceeding 1.22 meters (4 feet) in depth. Never climb in or out by stepping on cables or hangers.

2. Attendant:

• While work is being performed in a manhole or vault containing energized electric equipment, have an employee with first-aid and cardiopulmonary resuscitation (CPR) training available on the surface in the immediate vicinity of the entrance to render emergency assistance.

• Ensure employees maintain reliable communications, through two-way radios or other equivalent means, among all employees involved in the job.

3. Identification and Protection of Cables:

• Identify the cable to be worked on by electrical means, unless its identity is obvious. Protect other cables from damage.

4. Equipment and Tools:

• Equipment used to lower materials and tools into manholes or vaults must be capable of supporting the weight to be lowered and must be checked for defects before use.

5. General:

• Keep tunnels or manholes containing energized conductors or equipment free from water, sewage, or other drainage when it is necessary for workers to enter

• Ensure that means of access to all electrical switching devices are kept clear of obstructions

6. Warning signs

• Where more than one switch is installed with interconnected load terminals to provide for alternate connection to different supply conductors, each switch must be provided with a conspicuous sign reading: "WARNING--SWITCH MAY BE ENERGIZED BY BACKFEED."

7. De-energizing and Lockout/Tagout Procedures:

• Before working on a power system that for reasons of safety must be de- energized, the worker in charge must ensure that the part of the system being worked on is isolated and grounded, and locked out as required by regulations.

8. Switching sequences

• If a switching sequence requires the operation of 3 or more devices, a written switching order must be prepared and followed.

9. Isolating devices

• Isolating devices used for safety protection guarantees must provide for visual verification of the opening of the isolation point.

• Lockable isolating devices must be locked in the position or condition required to protect workers before work commences under a safety protection guarantee.

• A distinctive "DO NOT OPERATE" tag must be placed securely on each isolating device used for a safety protection guarantee.

10. Grounding and blocking

• After a safety protection guarantee is in effect, the equipment to be worked on must be tested to verify isolation before grounding and blocking begins.

• After testing to verify isolation, the person at the worksite responsible for each crew must verify that required grounding and blocking devices are in place before work begins.

• Grounding and blocking of any equipment that may be hazardous to workers must be carried out as close as practicable to the worksite.

• If grounding and blocking is not safe or practicable, written safe work procedures acceptable to the relevant regulatory body must be followed.

11. Multiple authorities

• If a safety protection guarantee involves 2 or more power systems, or 2 or more persons in charge of different parts of a system, appropriate written procedures must be established and followed to ensure that any safety protection guarantee will be effective.