FDNY A.U.C. 181: Overhead Electric Utility Fires and Emergencies Study Guide

Electric Power Delivery System Overview

** NYC Power Delivery Sub-systems**: The system is divided into three distinct components:
  - *Generation*: Central power plants produce the electricity.
  - *Transmission*: High-voltage lines carry power from plants to area substations.
  - *Distribution*: Substations reduce voltage to primary levels; primary lines distribute to street transformers; street transformers step down voltage for the secondary system; service lines supply individual buildings.
Voltage Classifications:
  - Transmission Lines: Typical voltages include $69\,kv$ , $138\,kv$ , or $345\,kv$ .
  - Primary Lines: Distribution levels of $4\,kv$ , $13\,kv$ , $27\,kv$ , or $33\,kv$ .
  - Secondary Lines: Low voltage delivery at $120/208\,v$ , $120/240\,v$ , or $277/480\,v$ .
Service Providers and Infrastructure:
  - Consolidated Edison (Con Ed): Distributes power throughout most of NYC.
  - PSEGLI: Provides power to Rockaway, Queens.
  - Overhead Systems: Found in every borough except Manhattan. This guide does not cover railroad-owned overhead systems found on railroad rights of way.

Utility Poles and Overhead Hardware

Utility Pole Composition and Ownership:
  - Poles are made of pressure-treated wood.
  - Ownership Split: Electric utilities own approximately $60\%$ of the poles, while phone companies own the remaining $40\%$ .
  - Leasing: Other telecommunication providers (Cable TV, fiber optic) lease space on these poles.
Equipment Positioning and Danger Hierarchy:
  - General Rule: Higher equipment is typically more dangerous, with the exception of Aerial Cable.
  - Vertical Ordering (Highest to Lowest):
    1. Primary Lines: Usually the highest if present.
    2. Secondary Lines: Highest if primary lines are absent.
    3. Aerial Cable: Usually mounted below secondary electric cable.
    4. Telecommunications: Phone and Cable TV are lower on the pole.
  - Identification: Each pole should be badged or numbered. Poles with high voltage should be labeled with the highest voltage present. Providing the pole number to the dispatcher facilitates better utility response.

Overhead Electric Cable Types

Primary Cable:
  - Function: High voltage distribution from substations to geographic areas/transformers.
  - Position: Mounted highest on the pole.
  - Voltage: Ranges from $4,000\,kv$ to $33,000\,kv$ .
  - Hazard: Uninsulated. Poses severe electrocution hazard through direct contact or proximity (energy can jump to conductors).
Secondary Cable:
  - Function: Low voltage system supplying most customers.
  - Position: Mounted below primary lines, or at the top if no primary exists.
  - Identification: Look for service lines connecting the cable to buildings.
  - Voltage: $120/208\text{-}240\,v$ .
  - Hazard: Insulated, but insulation is often compromised by age or wear.
Primary Aerial Cable:
  - Function: Express lines supplying large customers or equipment; alternates between underground and overhead systems.
  - Position: Runs just below secondary (low voltage) wires; this is a dangerous exception to the height rule.
  - Identification: Suspended on a steel line with rings or "saddles" every $1.5\,feet$ . It features splice boxes often mistaken for phone boxes.
  - Voltage: $4,000\,kv$ to $33,000\,kv$ .
  - Hazard: Insulated, but susceptible to wear/tear.
Service Line:
  - Function: Connects the building to the pole.
  - Origin: Starts at the secondary line on the pole and ends at the building's electric service mast.
  - Construction: Two insulated "hot" legs and one neutral/ground wire.
  - Voltage: $120/208\text{-}240\,v$ .

Customer Connection and Monitoring

Electric Service Mast:
- Components: Rigid metal conduit, capped with a "weatherhead" (weather-proof cap), and connected to an electric meter.
- Ownership: Damage and maintenance of the mast is the responsibility of the customer.
Electric Meters:
- Standard Meters: Require monthly manual readings.
- AMI Meters: Automatic Meters that allow remote monitoring and remote shutdown by the utility during emergencies.

Transformers, Switches, and Risers

Pole Mounted Transformers:
  - Function: Step-up or step-down voltage between primary and secondary systems. Always contain high voltage.
  - Cooling/Insulation: Filled with combustible oil.
  - Identification: Connected by cables to both the primary (top) and secondary systems.
Switches:
- Function: Act as large circuit breakers used to disconnect the primary system.
- Identification: Only connected to the primary system (unlike transformers).
Risers:
  - Function: Conduits running up the side of a pole connecting underground systems (manholes) to overhead systems.
  - Primary Riser: Contains high voltage cable connected to primary lines.
  - Secondary Riser: Connected to secondary lines.

Defined Electrical Hazards

Touch Potential: Electrocution via contact with a wire or an object energized by a wire.
Step Potential: Downed high-voltage wires create voltage gradients on the ground. Walking toward or away from the source can cause shock/electrocution without direct contact with the wire.
Arc Potential: Electricity "jumping" from an energized object to a nearby ladder or tool; physical contact is not required for electrocution.

Operational Procedures for Emergencies

General Safety:
- Position apparatus outside the affected area and the established Safety Area.
- Safety Area: Cordoned off to pedestrians and vehicles; includes a minimum distance of $2\text{ utility poles}$ in each direction from the emergency.
Wires Down:
  - Treat all wires as live.
  - For dormant wires: One engine company.
  - For live wires in the street: Engine company, Ladder company, and Battalion Chief (BC).
  - Person Trapped: If life is in danger, dispatch Engine, Ladder, Rescue, and BC. The BC must contact the Utility Electric Control Center via battalion cell phone for immediate power removal.
Vehicle Accidents involving Poles:
- Polls may crack or become unstable; check surrounding poles for collision damage.
- Trapped Civilians: Instructions are to stay in the vehicle. If fire necessitates exit, occupants must jump clear (no contact with car and ground simultaneously) and hop away with both feet together.
Overhead Electric Fires:
  - Prepare for wires falling; evacuate surrounding properties or keep civilians inside if safer.
  - Check exposures using thermal imaging cameras, specifically service masts and interior electric boxes.
  - Extinguishing Secondary/Service/Telecom Fires: At BC discretion, use a handline with a $30\text{-degree}$ or greater fog stream. Maintain a nozzle distance of at least $25\,feet$ . Rain the stream down from above; do not aim directly at the fire.
  - Extinguishing Primary/Aerial Cable Fires: Preferred tactic is to wait for the utility. Water can create ground paths or drop wires onto wet pavement. Purple K may be used if safe distance allows.

Pole-Mounted Transformer Fires and PCB Protocols

PCB Hazard: Transformers and switches may contain PCBs (as of March 2022). Mandatory use of full PPE and SCBA due to toxic smoke.
Boilover Risk: Water applied to burning transformer oil can cause a boilover, creating a plume of burning liquid and a 3-dimensional fire on the ground.
Tactics:
  - Initial action: Avoid water. Transmit signal 10-86 for Purple K, F500, and Foam response.
  - Purple K: The only agent recommended for direct use on the transformer prior to utility arrival (if safe distance allows).
  - Post-Utility Arrival Agents (in order of preference):
    1. F500: Carried by Haz-Mat 1; highly successful on transformer fires.
    2. Foam.
    3. Water Spray.
  - Requirements: Minimum $25\,feet$ standoff and $30\text{-degree}$ fog/rain-down stream.
Decontamination (Haz-Mat Battalion Consultation):
  - Technical Decon: Special call Decon Task Force for members exposed to smoke or oil spray; includes bunker gear collection.
  - Personal Decon: Special call Decon Shower Apparatus for member showers.
  - Apparatus/Tools: Haz-Mat Battalion determines if on-scene decon is possible or if collection is required.