SWI: Electrical Manhole - Annual Preventive Maintenance

Job Briefing

• Establish roles and responsibilities for each team member, including a dedicated confined space monitor.

• Ensure team members are aware feeders om vault are energized.

• Notify team members of manhole voltage: 25K Volts

• Check surrounding area for abnormal conditions. Correct or stop work if present.

• Ensure an appropriate rescue plan is in place with retrieval mechanism(s).

Barricade Area

• Place traffic cones to surround the jobsite providing not less than 20-feet of clearance on all sides.

• Barricade the area with RED DANGER TAPE to protect the open hole and crew performing the work.

Pre-Lid Removal Checks

• Review plan for lid removal safety and hazards of an open hole.

• Inspect lid for heat, smoke, pressure, unusual sounds, odors, or other indications of an electrical fault or hazardous condition.

Open Manhole

• Slowly and carefully remove the lid using appropriate tools and body-positioning practices.

• Place lid "flat" on the pavement/earth with at least one block/spacer underneath to facilitate handling when time for replacement.

Pre-Entry Permitting/Ventilation/Testing

• Obtain a Confined Space Permit and follow all provisions.

• Ventilate the manhole with clean air using a portable forced-air blower and ducting approved for confined-space use and suitable for the potential hazardous-location classification. (Note: Locate the blower intake in a clean area, upwind and away from vehicle exhaust, generators, combustion equipment, chemical releases, and other contamination sources.)

• Complete Atmospheric Testing: Test the atmosphere remotely using a calibrated direct-reading instrument. Test throughout the manhole, including the upper, middle, and lower levels. Test atmosphere before entry and continuously during entry.

• Initiate surface attendant and rescue provisions per confined-space classification.

• Ensure only QUALIFIED ELECTRICAL RESOURCES enter the space.

Before entering manhole, inspect for standing water. Record water depth prior to action.

Note water condition

If water was present, note the condition and escalate if unusual. (Check all that apply.)

• Clear/rainwater

• Muddy water

• Oily sheen

• Chemical odor

• Biological material

• Unusual discoloration

Identify which duct, wall penetration, or joint appears to be allowing water entry. Include photos if practical.

Check walls, floor, roof for issues:

• Cracks

• Spalling

• Exposed rebar

• Delamination

• Deformation

• Settlement

Inspect frame and chimney:

• Cover frame

• Riser/chimney

• Grout

• Brick or concrete collar

Check duct bank entries:

• Failed duct seals

• Missing plugs

• Broken conduits

• Loose grout

• Soil infiltration

Inspect cable racks/supports:

• Corrosion

• Loose anchors

• Missing hardware

• Sagging supports

• Sharp edges

Inspect ladder/steps:

• Corrosion

• Looseness

• Missing rungs

• Unsafe condition

Check grounding/bonding bar:

• Corrosion

• Looseness

• Missing conductors

• Mechanical damage

Inspect cables

• Jacket damage

• Swelling

• Cuts

• Abrasion

• Cracking

• Tracking

• Water treeing indicators

• Exposed shield

• Deformation

Check splices

• Swelling

• Oil/compound leakage

• Tracking

• Heat discoloration

• Cracking

• Poor support

• Submersion history

Inspect terminations, if present

• Tracking

• Corona evidence

• Loose support

• Contamination

• Cracked stress cones

• Signs of overheating

Confirm feeder tags are present, legible, durable, and match drawings

• Yes
• No
• N / A

Confirm phase markings are present and legible

• Yes
• No
• N / A

Visually inspect grounding/shield bonding

• Bonding jumpers

• Shield grounds

• Concentric neutrals

• Clamps

• Corrosion

Confirm cables are properly supported and not rubbing, pinched, crossed under strain, or resting in sediment

• Yes
• No
• N / A

Inspect fireproofing/firestopping

• Fire wrap

• Fire blankets

• Duct seals

• Penetration sealing

Check for rodent/insect activity

• Nesting

• Gnawing

• Debris

Perform infrared inspection of visible energized cable splices, terminations, and connection points where safely accessible and with sufficient load.

• Yes
• No
• N / A

Document any temperature differential at or above 4-degrees Celsius. Include photos if practical. Include specific details of affected area and temperature deviation (delta T). STOP WORK AND ESCALATE IMMEDIATELY IF TEMPERATURE DIFFERENTIAL EXCEEDS 15-deg Celsius.

Demobilization from Manhole

• Confirm all required inspections and work tasks have been completed, including photos and inspection readings.

• Remove all tools, test equipment, pumps, hoses, extension cords, lighting, ventilation ducting, meters, buckets, rags, and other temporary work materials from the manhole.

• Inspect the manhole interior for dropped tools, loose hardware, debris, trash, or foreign material.

• Exit manhole and confirm all personnel are accounted for.

• Clean lid support ledge as needed to remove debris and ensure suitable lid seating.

Demobilization from Jobsite

• Replace manhole lid. CAUTION: Lid is heavy. Use approved lifting tools and body-positioning practices.

• Close out confined space entry permit, including signatures.

• Remove barrier tape and traffic cones used to secure the area.

• Dispose of trash and debris. Clean from paved areas any significant amounts of mud/sediment resulting from dewatering.

• Return all tools, test equipment, pumps, hoses, extension cords, lighting, ventilation ducting, meters, buckets, rags, traffic cones, and other temporary work materials to normal storage locations.

Work Order Closeout

• Generate any necessary corrective work orders based on findings.

• Record time expended on work order.

• Add any additional comments that may be beneficial to reviewers.

• Close out when complete.