Enclosed Space Entry & Rescue
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Operational Excellence is built upon six guiding principles: •Foundation
•Deliberate Conduct Of Operations •Commitment To Quality •Operational Preparedness
Enclosed Space Entry & Rescue
This course is intended to meet the minimum requirements of the Electrical Enclosed Space
Procedure (CEHSP S1701), including atmospheric testing and rescue and resuscitation.
The course is divided into three parts: • Safety Overview
• Enclosed Space Entry
• Enclosed Space Rescue
Before We Begin
1.1 Job Briefing
1.2 Evaluation of Potential Hazards
1.3 Atmospheric Testing
1.4 Order of Testing
1.5 Air Sampling Procedures for Manhole Atmospheres
1.6 Sampling Procedures for Manhole Atmospheres
1.7 Forced Air Ventilation
1.8 Ventilation Procedure
1.9 Trained Attendant
1.10 Myths about Hazardous Atmospheres
1.1 JOB BRIEFING
The job briefing is the first and most critical step in every job. Job briefings are discussions among all crew members to ensure that everyone understands the work and their respective roles before starting any task. Whether the job entails work under emergency conditions or normal operating conditions, a job briefing is the first step.
The employee in charge shall conduct and document a job briefing and cover the following topics:
• Hazards associated with the job
• Work procedures
• Special precautions
• Energy source controls (Live work)
• Personal protective equipment
(FR clothing, safety glasses, etc.)
The minimum personal protective equipment for con Edison employees, contractors, and visitors for work covered in the scope of this procedure are safety shoes, hardhat, eye protection, and FR clothing (where electrical flash hazards exist or hot work operations are conducted). The FR clothing requirements are outlined in
Additional briefings must be held if significant changes, which might affect the safety of the
employees, occur during the course of the work. Completion of a job briefing must be documented.
1.2 EVALUATION OF POTENTIAL HAZARDS
Before an entrance cover to an enclosed space is removed, it must be determined that removal can be done safely and that the condition of the electrical facilities contained therein is sufficient to allow unrestricted access and emergency rescue. Prior to entry, a qualified Con Edison employee or equivalently trained individual must conduct an initial inspection. This initial inspection will determine if the condition of the electrical facilities within the enclosed space is sufficient to allow unrestricted access.
Gallery 1.1 Defective Straps
1.3 ATMOSPHERIC TESTING
Before an employee enters an electrical enclosed space, the atmosphere in the space shall be tested with a direct-reading meter or similar instrument, capable of collection and immediate analysis of samples without need for off-site evaluation. Con Edison employees may only use the MSA Altair 5X Multigas Detector or Drager X-am 7000.
Initial monitoring shall be documented, including time and results.
Structures required to be de-watered must be tested for a safe atmosphere prior to operating pumps or similar equipment and prior to entry/re-entry. Continuous atmospheric monitoring is required at all times while entrants are in the enclosed space. The monitor inlet must be positioned at a height of approximately 4 feet above the working surface to correspond with the breathing zone.
Atmospheric testing is required prior to space entry for the following reasons:
• To evaluate the hazards and to verify that acceptable conditions for entry exist.
• To ensure that acceptable conditions are maintained during the entry work.
1.4 ORDER OF TESTING
The internal atmosphere shall be tested using an approved, properly calibrated Atmospheric Testing Device, in the following sequence:
• Oxygen (acceptable criteria between 19.5 and 23.0%). Oxygen monitoring equipment shall be set to alarm if the oxygen content falls below 19.5 percent.
•Flammable gases and vapors (acceptable criteria less than 10% of the lower explosive limit (LEL), e.g., a reading of 0.5% methane).
•Carbon monoxide (CO) (acceptable criteria less than 35 parts per million [ppm]).
•Tests for toxic vapors and gases, if necessary. Entry level for toxic substances shall not exceed the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL), regardless of the anticipated length of entry.
Interactive 1.1 Atmospheric Testing
Initial readings will be documented including the time and results. For entry into pipe type feeder
manholes that are connected to SF6 equipment, the Chem Lab must be contacted if there has been a fault to perform monitoring (see GEHSI S17.01.01, Electrical Enclosed Space Entry).
Where hazardous atmospheres are suspected, it is permissible to “pre-test” the space with an instrument not approved under CEHSP S17.01 (Electrical Enclosed Spaces, section 4.4.2) for one or more concerns. This is desirable to minimize potential damage to a space entry gas detector through overexposure. Regardless of the results and actions of any such pre-test, proper testing for all concerns using an approved instrument must be performed prior to actual space entry.
1.5 AIR SAMPLING PROCEDURES FOR MANHOLE ATMOSPHERES
Enabling Objective: State the conditions that require air sampling of confined spaces.
DO NOT work in any manhole or enclosure where inert gases are used until tests have been made to show sufficient air and the absence of combustibles.
Ventilate before entering a manhole having a Gas Warning sign.
1.6 SAMPLING PROCEDURE FOR MANHOLE ATMOSPHERES
The detector must first be operated in fresh air. The MSA Altair 5X will continuously and simultaneously monitor Oxygen, Carbon Monoxide and combustibles.
Observations of the atmosphere in the manhole shall be made at a level approximately two feet from the top, near the middle of the manhole, and at a level near the bottom. If water should be present in the manhole, the latter observation should be made at a level just above the surface of the water. Care should be taken not to immerse the end of the sampling hose in water. When exposed to water, the filter at the end of the sampling hose will automati- cally close to prevent any material or gas from enter- ing the tube.
Insert a ladder into the structure and take samples around the casting and chimney. While descending the ladder, take samples to the right and left for three levels.
Check the remainder of the manhole from the tested area.
Check remaining area at duct edges, corners, cracks, and other irregularities.
1.7 FORCED AIR VENTILATION
Enabling Objective: State the conditions that require forced air ventilation of a manhole.
If combustible gases or an oxygen deficient atmosphere is present, the confined space must be ventilated for a minimum of 10 minutes. The Figure shown is used to determine the purging time for vari- ous sized manholes as a function of blower capac- ity. By lining a straight edge between our two plotted points, one on the volume (ft3) scale and the other on the blower capacity scale, the point of intersection on the time scale denotes the minimum ventilating interval.
If combustable gases or vapors are detected the local control center must be notified immediately.
1.8 VENTILATION PROCEDURE
Enabling Objective: State the proper forced air ventilation procedure.
In a previous section, you learned that a power ventilator blower is used to force air into a structure. In this section, you will learn how to use the power ventilator blower. The following steps are to be followed when using this tool. GEHSI S17.02.02, Ventilation of Underground Structures, provides guidance on how to properly ventilate underground structures.
•The power ventilator shall be kept at a safe distance and secured from the enclosure opening to prevent air recirculation.
• Ensure that the blower hose is not unnecessarily bent.
• Purge the blower hose outside of the enclosure for at least one minute to prevent the possibility of introducing contaminants into the enclosure.
• If a tent will be used over the enclosure opening, the power ventilator must be kept outside of the tent and the tent sides must be one foot off the ground for air circulation.
• Purge the confined space for at least 10 minutes, or, if a tent is used, purge for at least 15 minutes.
• After the required purge time has elapsed, sample the atmosphere of the enclosed space. If the results are unsatisfactory, continue the air purge for an additional 10 minutes.
• Once the gas analysis has passed, personnel may enter the enclosure to take additional air samples. Test areas include corners, duct edges, cracked ar- eas, top of sumps, etc.
• Move the blower hose onto a cable rack so that its output is on a horizontal plane. This is the ventilate mode.
•Perform atmospheric test at least every 2 hours when using powered ventilation.
• If water is present in the vault or manhole, it must be pumped out and another air sample must be taken. Air samples must be taken immediately after
a sealed duct is opened.
After entering the manhole, place the outlet portion of the blower hose in a horizontal position on a cable rack or along a side wall approximately midway between the floor or platform and the splicing chamber or vault roof.
When the manhole is first opened, maximum air flow should be introduced into the manhole as rapidly as possible for a minimum of 10 minutes. The blower hose should hang straight down, eliminating as many flow restrictions as possi- ble, as shown.
1.9 TRAINED ATTENDANT
While work is performed in an electrical enclosed space, a trained attendant shall be available in the immediate vicinity to render emergency assistance. The attendant shall not be distracted from the duty such as speaking on a cell phone, text messaging, or use of other hand-held devices. This person is not precluded from performing other duties outside the electrical enclosed space if these duties do not distract the attendant from monitoring employees within the space. This does not preclude more than one person entering the structure. An attendant is not precluded from reaching into an underground structure to hand an entrant tools or other job materials so long as only the hands/arms break the
entry plane. Manhole attendants must be trained in first aid, cardiopulmonary resuscitation
(CPR), and rescue.
Interactive 1.4 Click to view
1.10 MYTHS ABOUT HAZARDOUS ATMOSPHERES
I can tell when there’s a problem in a vault or manhole.
WRONG. Most contaminants in a vault will have little or no odor. If they do have an odor, it will probably be slight compared to the general smells that are encountered in a subsurface structure.
If my instrument shows the permissible concentration of oxygen, there can’t be anything else in the structure, because it would make the oxygen level drop.
WRONG. The more dangerous contaminants that might be present can be harmful at very low concen- trations. These low concentrations will not cause an oxygen meter reading to change in any way.
The only time I need to worry about what’s in a structure is if there was a recent burnout or fire.
WRONG. A fire or burnout can cause higher levels of carbon monoxide, a dangerous gas. However, carbon monoxide or other gases could enter an underground structure through conduits from other
structures, through sewer lines, or through the soil or fill surrounding the structure.
If the oxygen level is low, I’ll notice and get out of the hole.
WRONG. While oxygen levels
slightly below the normal level of
21% may cause warning signs such as headache or fatigue, levels just a few percentage points lower will cause almost immediate loss of consciousness. Any loss of consciousness can result in a fall or contact with an energized component which by itself can be fatal.
I don’t need a testing instrument. I used to work in structures before testing instruments existed.
WRONG. While workers may be able to play the odds and not encounter problems, one bad decision can have tragic implications. Most fatalities and injuries in confined or enclosed spaces involved workers who have done the same job many times before without a problem.
DON’T TAKE CHANCES...USE YOUR TEST INSTRUMENT!
Enclosed Space Entry
2.1 Enclosed Space Entry
2.2 Con Edison Initial Entry and Visual Inspection
2.3 Entry by Con Edison Personnel
not qualified for Electrical Work, Contractors, or Public Improvement Personnel
2.4 Use of Equipment by Con Edison Employees and/or Contractors
2.1 ENCLOSED SPACE ENTRY
Enabling Objective: Describe the provisions and requirements of Con Edison's enclosed space entry.
What is an Electrical Enclosed Space?
CEHSP S17.01, Electrical Enclosed Spaces, de- fines an enclosed space as the following:
A working space, such as a manhole, vault, tunnel, service box, or shaft, used for the operation and maintenance of electric power generation, transmission, and distribution lines and equipment. An electrical enclosed space has a limited means of egress or entry, and is designed for periodic employee entry under normal operating conditions. Under normal conditions, an electrical enclosed space does not contain a hazardous atmosphere, but may contain a hazardous atmosphere under abnormal conditions.
GEHSI S17.01.01, Electrical Enclosed Space Entry, provides guidance on routine entry into electrical enclosed spaces.
GEHSI S17.02.01, Gas Enclosed Space Entry, provides guidance on routine entry into gas enclosed spaces.
Employees shall not enter any enclosed space that contains a hazardous atmosphere, unless the entry is performed as required by CEHSP S16.00, Permit- Required Confined Space.
• Trainees who enter electric enclosed spaces who are partnered with qualified employees may enter enclosed spaces.
•A qualified person is an employee who, by knowledge, training and experience, has success- fully demonstrated the ability to solve problems re- lating to the work in electric enclosed spaces.
• An employee who is undergoing on-the-job training and who, in the course of such training, has demonstrated the ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is considered to be a qualified person for the performance of those duties.
All of the following must be performed prior to entering an Electrical Enclosed Space:
Conduct a job briefing
Provide a safe work area
For electrical enclosed spaces, test for
stray voltage in accordance with ELE0020 and cover temperature (test for proper atmosphere if cover is ventilated)
Protect opening using an approved guard rail
For electrical enclosed spaces, de-energize any D-Faulted equipment, if any, prior to entry
A trained attendant must be present
Over time, manhole covers may become difficult to remove due to exposure to the elements and traffic. This is because debris fills in voids and deformation of the casting occurs with the impact of NYC traffic. Asphalt and debris from road work will fill the notches where manhole hooks are to be placed for cover removal. If those notches are not cleaned out properly, or are shallow, it is common for manhole hooks to disengage suddenly when pulling. It is recommended to pull manhole covers away from traffic. This cannot always be done due to limited space. If covers must be pulled in the direction of traffic, employees MUST be aware and look for oncoming traffic to avoid serious injury or fatality.
2.2 CON EDISON INITIAL ENTRY AND VISUAL INSPECTION
Once the structure is initially entered, a visual inspection shall be conducted for exposed live conductors, improperly sealed cable ends, visual burnouts, structural damage, D-Fault tags, environmental tags, and cable ends cut excessively long where the cable-end could contact the structure cover/grating or metal frame.
The visual inspection shall be documented.
In addition, abnormalities, such as oil or compound leaking from cable or joints, broken cable sheaths or joint sleeves, hot localized surface tempera- tures of cables or joints, or joints that are swollen be- yond normal tolerance are presumed to lead to or to be an indication of an impending fault. These abnor- malities are referred to as “D-Faults.”
EO-1184, Identifying Cable and Splice Abnormalities On Distribution Feeders, shall be followed to deter- mine when a cable must be de- energized for work in a manhole.
If a D-Fault is noted, it must be reported and the structure shall be exited immediately. If a D-Fault tag, environmental tag, or any unsafe condition is found further steps shall only be taken with consent and advice of the control center and/or field supervi- sor.
Cable inspections are not required for enclosed spaces where electrical equipment has not been pre- viously tied into the system, or for service boxes with no primary cable.
2.3 ENTRY BY CON EDISON PERSONNEL NOT QUALIFIED FOR ELECTRICAL WORK,
CONTRACTORS, OR PUBLIC IMPROVE- MENT PERSONNEL
If entry takes place immediately after the initial inspection, a follow-up inspection is not required provided that the Con Edison inspector or the contractor foreman were on location during the initial inspection by the qualified electrical worker. If entry by non-qualified personnel (i.e., Con Edison employees not qualified for electrical work, and contractors) is not immediate but takes place within 72 hours of the initial inspection, a “follow-up inspection” shall be conducted prior to each entry.
The follow-up inspection shall be conducted by a qualified person (Con Edison or contractor trained by Con Edison) involved in the work and include:
Verification that the initial inspection was performed in the specified time frame.
Testing for stray voltage by a qualified Con Edison employee or qualified contractor.
Completion of atmospheric testing as outlined in Chapter 1.
Determination that it is safe to enter the space.
A visual inspection for abnormalities such as faults or non-capped cable.
Communication of inspection results and hazards to the con Edison inspectors and the contractor foreman.
If entry is delayed past the 72 hours, the initial inspection shall be repeated. Qualified
telecommunication employees and their contractors accompanied by qualified Con Edison personnel do not need to repeat the initial inspection until 30 days has expired. Con Edison personnel not qualified for electrical work may only enter after the “follow-up” inspection is conducted by qualified personnel.
Follow-up inspections shall be documented. Service boxes without primary service are exempt from the initial inspection however shall have the equivalent of the “follow-up inspection”.
Note: This section does not apply for enclosed spaces where electrical equipment has not been previously tied into the system.
2.4 USE OF EQUIPMENT BY CON EDISON EMPLOYEES AND/OR CONTRACTORS
Con Edison employees may use the contractor’s ladders or rescue device, if visually inspected before use, and found to be in proper working order and the Con Edison employees were trained in that device. Atmospheric monitoring equipment used by or for Con Edison employees shall be Con Edison equipment only. Contractors may use Con Edison equipment with prior approval from Con Edison personnel supervising the work.
Enclosed Space Rescue
3.1 Enclosed Space Rescue 3.2 Rescue Devices
3.3 Retrieving the Victim
3.4 Aiding the Victim
3.1 ENCLOSED SPACE RESCUE
Enabling Objective: Describe the provisions and requirements of Con Edison's enclosed space rescue and resuscitation program.
The enclosed space rescue and resuscitation program describes the rescue and resuscitation
techniques to be followed when an underground worker requires assistance to be removed from an enclosed space. This procedure applies to all employees (entrants and attendants & Contractors) who work in electric transmission and distribution enclosed spaces. Examples of situations that may require rescue or resuscitation include:
• Illness (of a degree to preclude self-rescue)
• Injury (burns or fractures)
• Unconsciousness (physical blow, electric shock or heart attack)
3.2 RESCUE DEVICES
DBI SALA 8302500 INSPECTION
The following must be inspected:
•All structural components of the rescue device including support legs, upright column or boom arm shall be straight and free from deformations (curves or bends).
• There shall be no evidence of cracks on welds or any other part of the device.
•All legs of a single device shall have the same base-type component to make contact with the ground so as to ensure even footing.
•Rescue line shall be free from cuts or tears or other visible damage. In addition, the rescue line shall not exhibit any fraying.
• The locking clip on the retrieval snap hook shall be checked each time the device is set up for proper operation. Particular attention shall be given to hooks that exhibit rusting.
• The winch shall be checked for proper operation, and all gears shall be checked for missing teeth.
•All bolts installed on the device shall be present and secure.
• The securing pin (detent pin) must be present for safe storage.
Interactive 3.1 DBI SALA Features Reflective Label
Winch Crank Arm Handle
Lower Arm Base Socket
Winch Line Lifting Hook
Davit Arm Storage Strap
ID Warning Label
Base Storage Strap
The following steps must be followed when setting up rescue devices:
•Upright column shall be full inserted into center support column.
• All legs shall be fully extended so as to be flush against the center support column.
• All legs shall be placed so that they will have even footing so as to prevent wobbling or rocking action.
• In the event of a rescue, boom shall be centered over the load so that the retrieval line is in a verti- cal post.
• When operating the winch, the operator shall place his/her free hand on the device, behind the winch to stabilize the winch and counteract any rocking action.
• Maximum load is 350 lbs.
• If the rescue device is to be set up on an inclined surface, the device shall be positioned on the lower side of the incline so that the boom faces in an uphill direction.
• Retrieval equipment must be inspected to ensure proper function, and be available outside of the truck at the job site prior to the start of work.
Before the actual work tasks begin, the retrieval device must be set up at the space entrance, or nearby so that employees can be promptly and safely extracted from the space.
The placement of the retrieval device will be deter- mined during the job briefing, based on potential haz- ards in the space and around the work area. For structures less than 48" in depth, the retrieval device does not have to be set up. When accessing the top of a transformer directly from street level to place grounds, if the top is within 48" of the grating and there is no potential to fall further into the structure, the retrieval device does not have to be set up.
The preferred placement of the self-supporting ex- traction device is always at the structure opening, in position to facilitate immediate use for rescue. If the work area cannot be configured to support this place- ment, the device may be positioned elsewhere in- side the work area, but personnel must ensure that they have identified the location where the device would be set up to facilitate rescue, and maintain that area free of material or equipment.
A ladder must be placed in the electrical enclosed space at all times during work in the space, unless it is impractical due to the position of the ladder in relation to the work tasks in the structure. If impractical, then the ladder must be positioned within reaching distance of the attendant at the entrance into the space.
Remote Rescue System
If structure conditions make entry unsafe, the re- mote rescue system can be used. This system al- lows the hook and line from a rescue device to be extended for attachment to the victim’s harness by way of a telescopic pole. The remote rescue device is available as a kit that contains the telescopic pole and a rescue hook. The rescue hook may be affixed to any exposed part of the victim's harness.
INSPECTION OF REMOTE RESCUE SYSTEM
The carrying bag shall be inspected for rips, tears, or other damage that would compromise the
protection of the Remote Rescue System equip- ment. Bags that are damaged shall be replaced. If the condition of the carrying bag requires its replace- ment, all of the components of the system shall be inspected as indicated in the annual inspection pro- cedure listed below.
The following inspection shall be performed annually by a qualified person:
The carrying bag shall be inspected for rips, tears, or other damage that would compromise the protec- tion of the Remote Rescue System equipment. Bags that are damaged shall be replaced.
The following operational checks shall be made:
•Rescue hook gate shall operate freely and the hook shall readily release from the holder.
•The rescue stick shall be free from damage (cracks, burns, exposed fibers, etc.) and readily extend from the stored position. The entire length of the rescue stick shall be inspected.
After the inspection has been completed and any damaged components replaced, the rescue hook holder, rescue hook, and rescue stick shall be placed in the appropriate compartments of the carry- ing bag. The inspection tag shall be filled in with the identity of the person who performed the inspection and the date the equipment is due for re-inspection.
The black plastic clasp that is used to secure the flap of the carrying bag shall be secured.
DEPLOYMENT OF REMOTE RESCUE SYSTEM
Prior to crew entry into electrical enclosed space, the Remote Rescue System shall be placed in an easily accessible location in the work area or on the vehicle. The equipment shall remain in the carrying bag and the seal that is installed on the clasp that secures the opening of the carrying bag shall not be broken unless the device is to be utilized for rescue operations
OPERATION OF REMOTE RESCUE SYSTEM
When a remote rescue needs to be performed, the following actions should be taken:
• Remove the carrying case from the vehicle.
• Remove the rescue stick and rescue hook from the
NOTE: Rescue hook is stored in a pocket. Access is through inside of case. Hook is visible through in- spection window
STORAGE OF REMOTE RESCUE SYSTEM
The Remote Rescue System must be stored in a se- cure location inside of the crew vehicle where it will not be impacted by materials, tools, or other equipment.
Remote Rescue Device Video
3.3 RETRIEVING THE VICTIM CALL 911 IMMEDIATELY!
If the enclosed space can be entered (check atmosphere):
• Carefully descend the ladder.
•Immediately look around the enclosed space for any obvious hazard.
• If the victim has made electrical contact, clear the victim from the hazard. If it appears that current is passing through the victim's body, do not touch the victim with any unprotected part of your body; use rubber, insulating gloves.
• Attach the retrieval line to the victim's harness.
•Center the victim under the enclosed space opening.
• Proceed out of the enclosed space and remove the ladder.
• Slowly raise the victim. Continuously watch the victim as he is being raised.
• Once the victim is clear of the enclosed space opening, gently set him/her on the ground and detach him/her from the retrieval line.
If the enclosed space cannot be entered (check atmosphere):
•Use the Remote Rescue System to remove the victim from the enclosed space.
3.4 AIDING THE VICTIM Injured and Conscious
If the victim is injured but conscious when you enter the enclosed space, try to reassure and calm the vic- tim. Most victims are disoriented after a sudden ill- ness or injury and are unable to evaluate their own situation.
If conditions permit give the necessary first aid. If conditions do not permit the administration of first aid in the en- closed space and the victim elects to ascend the ladder on his own, attach retrieval line to the victim and assist his ascent from above.
If the victim is unable to self-rescue, proceed with the evacuation as de- scribed above.
Continue to administer first aid and monitor condi- tion until trained, qualified assistance arrives.
Unconscious and Breathing
If the victim is unconscious and breathing when you enter the enclosed space and if conditions in the en- closed space permit (i.e. it is safe to remain in the structure and there is enough room), check the vic- tim's vital signs.
As long as it is safe to remain in the structure, continue to monitor the victim's vital signs and begin the administration of first aid as necessary until trained,
qualified assistance arrives.
Continue to monitor your surroundings and if conditions change such that your safety or the victim's safety would be compromised, prepare for immedi- ate evacuation.
Unconscious and Not Breathing
If conditions within the enclosed space permit (i.e. it is safe to remain in the structure and there is enough room), begin CPR until qualified assistance arrives.
If conditions in the enclosed space do not permit the administration of CPR, prepare for immediate evacuation.