PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
Topic Section
General Work Practice 1 Grounding Configurations 2 Grounding Transmission Lines with Distribution Underbuild 3 On A Wood Pole without Distribution Underbuild 4 With Master Grounds Installed Away from the Work Location 5 Grounding on Overhead Transmission Towers 6 Conductor Installation and Removal 7 Additional Precautions 8 Installing Grounds on Cable Terminals 9
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 1 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
1. General Work Practice Transmission Overhead Lines: Reference TAG-001
1.1. An Equipment Outage Request (EOR) or Clearance to Work (CTW) is submitted to de-energize the equipment. Protection Leader/Held For Person requests protection.
1.2. After protection/clearance is granted, the Protection Leader/Held For Person must notify all personnel when it is acceptable to test the conductor and install the grounds.
1.3. The Transmission Overhead Line personnel shall test to ensure the line is de-energized.
2. Grounding Configurations
2.1. Connect personal protective grounding to create an equipotential work zone (EPZ).
2.1.1. When utilizing Equipotential Zones, any conductive parts in reach of the lineman on the structure (i.e. guy wires, phone, cable) must be bonded to the rest of the grounded conductors to equalize the electrical potential. This includes any conductive materials or tools that could extend the employees reach and equipment and/or material that is within the Zone.
2.1.1.1. Conductive parts in reach of the lineman include uninsulated guy wires, static, or fiber optic OPGW.
2.2. Grounding on Overhead Ground Wires
2.2.1. Non-insulated overhead ground wires shall be electrically bonded to the structure grounding system prior to making contact with the overhead ground wire. (See Figure 1) The overhead ground wire shall always be bonded to the structure ground by a temporary protective ground cable when any part of the overhead ground wire connecting hardware is to be
disconnected. An EPZ shall be maintained at all times while making contact.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 2 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
2.3. Insulated Overhead Ground Wires
2.3.1. When work is performed in the vicinity or on insulated overhead ground wires, the Minimum Approach Distances must be maintained (See MAD Table in SAF-072 Main Section) or temporary protective grounds and EPZs shall be applied in accordance with this policy.
Typical Insulated Connection
Insulator
Temporary Energized OGW Used for Electric Communications Bond
Typical Steel Structure Connection
Mechanical Bond
Temporary Electric Bond Temporary Electric Bond Typical Wood Pole Connection Mechanical Bond
Overhead Ground Wire Attachments (Figure 1)
2.3.2. An Equipotential Zone shall be established at the work location.
2.3.2.1. On a steel structures, it is established using the structure itself and approved ground jumpers.
2.3.2.2. On wood poles, it is established using a cluster bar and approved ground jumpers.
2.3.3. When a grounding cluster is utilized, it must be placed immediately below or within close proximity of the working area of the lineman on the pole or structure.
2.3.4. At a minimum, the phase that is being worked on must have a personal ground at the work location.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 3 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
2.4. Preferred Grounding Methods
2.4.1. Combination Grounding – This is a method which is the safest and employs the use of master ground sets located on a section of transmission line with working grounds employed at the worksite by the crew. The crew may use a single ground at the work location provided this ground is installed and removed after working on each conductor attached to the transmission structure.
2.4.2. Worksite Grounding – This method is an alternative to the Combination method when work is confined at a single location. All conductors are grounded to an adequate ground source when this method is employed.
2.4.3. Bracket Grounding – A method of grounding which is a last resort when combination grounding or worksite grounding could cause a greater hazard as a result of a jobsite condition.
2.4.3.1. When bracket grounds are used, they shall be installed between the work area and all electrical sources of potential as defined in TAG-005.
2.4.3.2. Bracket grounds should be placed at the work site, or as close as possible to the work location.
2.5. Grounding for Broken Conductors
2.5.1. When conductors are broken and lying on the ground, grounds should be installed at locations on each side of the work area, and as close to the work as conditions will allow. An equipotential zone must be established.
2.5.2. When closing a circuit with a splice/jumper or cutting open a line, the circuit will be tied together or “jumpered or macked- out” with a set of protective grounds prior to the installation of the permanent jumper/splice or cutting it open to maintain equal potential across the opening.
2.6. Ground personnel shall be protected from hazardous differences in electrical potential. Protection for ground personnel shall be provided by several methods including: creating equipotential zones (EPZ), insulating and/or isolating equipment, and restricted work areas/limited access zones.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 4 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
2.6.1. A ground mat may be used to establish an EPZ for workers on the ground.
2.6.2. Rubber insulating equipment may be used to protect personnel handling grounded equipment and conductors from hazardous touch potentials. However, the insulating equipment must be rated for the highest voltage that can be impressed on the grounded objects under fault conditions.
2.6.3. Restricting and/or barricading of work areas where hazardous step or touch potential could arise may be employed to protect personnel not directly involved with the work. 3. Grounding Transmission Lines with Distribution Underbuild
3.1. Make the grounding connections in the following order:
3.1.1. Install a cluster bar on the pole just below the work area.
3.1.2. Install a 4/0 shunt from the cluster bar to the driven/screw in ground rod.
3.1.2.1. Due to structure configuration, if it is infeasible to install a 4/0 shunt from the cluster bar to the driven/screw in ground rod at that location, then equally effective alternative grounding configuration may be used. This may be accomplished by grounding in the manner described in this section one structure away and installing a cluster bar at the structure being worked on and attaching a bond from the cluster bar to the phase being worked on. MAD shall be observed from the unbonded phases.
3.1.3. Install a ground jumper from the best available ground source which may be the system neutral or a driven/screw in ground rod to the cluster bar. If necessary, install cover up to prevent the grounding jumpers from contacting energized conductors.
3.1.4. Jumper from the cluster bar to the closest phase conductor.
3.1.5. Jumper the other phases together, working from the nearest to the farthest away.
3.1.6. Remove the grounds in the reverse order.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 5 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
4. Grounding of Overhead Transmission Lines On A Wood Pole Without Distribution Underbuild
4.1. The grounding connections shall be made in the following order:
4.1.1. Install a temporary ground rod. Surround the ground rod with safety cones to remind workers of the hazard.
4.1.2. Install a cluster bar on the pole/poles and below the work area nearest the lowest conductor.
4.1.3. Clamp one end of the proper length jumper to the ground rod and the other end to the cluster bar(s).
4.1.4. Jumper from the cluster bar(s) to the closest phase conductor. Jumper to the other phases using the remaining jumpers. It is important to bond the phases together so that the protective devices operate properly.
4.1.4.1. Static/shield wires will be included in the grounding configuration.
4.1.5. Remove the grounds in the reverse order.
5. Grounding of Overhead Transmission Lines With Master Grounds Installed Away from the Work Location (Figure 2)
5.1. Conductor being worked on shall be grounded to the structure at the work location.
5.2. MAD distances shall be maintained on ungrounded conductors at the work location. 5.3. Breakaway bonds (1/0 copper) shall be connected from the uninsulated aerial work platform to the conductor being worked.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 6 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
Overhead Transmission Line Grounding With Grounds Installed Away from the Work Location (Uninsulated Aerial Device) Figure 2
6. Grounding on Overhead Transmission Towers
6.1. Inspect the tower structure grounds to make sure that they are in good condition. If not, the grounds must be repaired.
6.2. Install tower clamps on the tower legs, leaving adequate working space above them. 6.3. Clamp one end of the grounding jumper to the tower and the other end to the closest phase conductor. Install the other grounding jumpers to the tower and the other phases if required. 6.4. Remove the grounds in the reverse order.
7. Conductor Installation and Removal
7.1. All tensioning and pulling equipment shall be isolated, insulated or effectively grounded and an EPZ established around the conductor installation area. The installation area shall be barricaded to protect the public.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 7 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
7.2. A running (travelling) ground shall be installed between the tensioning reel setup and the first structure in order to ground each conductor during stringing operations.
7.3. When stringing or removing conductors near energized lines, suitable guard structures must be installed at points of crossing.
7.4. If the conductors being installed or removed cross over energized conductors in excess of 600 volts, and if the design of the circuit- interrupting devices protecting the line so permits, the automatic- reclosing feature of these devices shall be made inoperative.
7.5. Grounding dollies shall be installed on either side of energized conductor underbuild.
7.6. During stringing operations, each conductor shall be grounded at the closest possible structure adjacent to both the tensioning and pulling setup and in increments so that no point is more than 2 miles from an effective ground.
7.6.1. Where new lines are parallel to an energized line or if restringing conductors next to an energized line, installation of grounds will be required at shorter distances to drain electrostatic pickup (one set per mile).
7.7. Newly installed conductors shall be equipotentially grounded at dead- end or catch-off points.
7.8. Protective grounds shall be left in place until conductor installation is completed.
7.9. Protective grounds shall be removed as the last step of aerial clean-up.
8. Additional Precautions
8.1. The connection points of the grounds installed by Transmission Overhead personnel shall be connected at a distance to minimize the potential of removing the wrong ground.
8.2. When distribution circuits are connected to transmission circuits through the ground scheme, the personal ground requirement will be the same for the distribution circuit as for the transmission circuit. This personal ground shall be applied and removed with an approved live line tool.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 8 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
8.3. It is allowable to ground each lower conductor, and then climb past it to install grounds on the remaining conductors, provided the worker maintains the minimum approach distance (MAD) from any ungrounded conductor.
8.4. On new lines, grounds must be installed on the line no further than 2 miles apart to allow tying in, and other related work. A Personal Ground shall be used at the work location, on the phase being worked.
8.4.1. Where new lines are parallel to an energized line or if restringing conductors next to an energized line, installation of grounds will be required at shorter distances to drain electrostatic pickup (one set per mile)
8.5. When grounding for a non-electrical contractor (general contractor etc.), grounds shall be installed where the work is to be performed.
8.6. When lines are red tagged for Transmission Overhead Line personnel the line-to-ground disconnects shall be left open unless requested by the respective work crew leader.
8.7. When using an uninsulated aerial device, a break-away bond (1/0 copper) shall also be utilized between the basket and the conductive object(s). See definition of Bonding in SAF-072 Main Section.
9. Installing Grounds on Cable Terminal: Refer to UG Work Practice
9.1. When connecting or disconnecting the overhead conductors at the cable terminals, grounds are required on both sides of openings, that is, on the cable terminal spurs or rings and on the overhead conductors. If no ground spur is provided, the arrester lead will not be disconnected leaving the cable terminal ungrounded during the process of work being done by Transmission Overhead Line personnel.
9.2. After any phase of work is completed on a cable terminal by Transmission Overhead Line personnel such as, connecting or disconnecting overhead conductors, any grounds attached at the cable terminal will be removed.
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 9 of 10 Doc. ID: SAF-072 PERSONAL PROTECTIVE GROUNDING Attachment 1 Overhead Line Work Practices
9.3. Draining Cables
9.3.1. Before work is permitted on any cable or connected equipment that has been de-energized from normal line potential 1,000 Volts or higher, the cable must be drained for 30 minutes of any residual charge.
10. REVISION HISTORY
Date Revision Individual Reason / Comments Published Number Making Edits
02/21/18 000 A. Smith Initial Revision
PROPRIETARY, CONFIDENTIAL OR PRIVILEGED INFORMATION Verify Current Version Prior to Use — Uncontrolled When Printed
Rev. # 000 Page 10 of 10 Doc. ID: SAF-072