Occupancies Citywide Practice Exam

FDNY W27 Supervision of Stationary Energy Storage Systems (ESS) in Group R-3 Occupancies (Citywide) Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of the W27 Certificate of Fitness?
• Allow the storage of hazardous materials
• Permit the sale of residential battery products
• Authorize supervision of stationary ESS installations in R-3 occupancies
• Allow the use of portable generators

Rationale: The W27 certificate specifically covers supervision

responsibilities for stationary ESS in Group R-3 residential occupancies.

• A stationary energy storage system most commonly provides which

function? 1 / 4

• Water purification
• Compressed gas storage
• Backup or supplemental electrical power
• Space heating

Rationale: ESS units store electricity for later use, usually for backup or

load-shifting.

• Which authority regulates ESS installations in NYC?
• U.S. Department of Energy
• NYS Department of Buildings

C. FDNY

D. FEMA

Rationale: FDNY governs permitting, safety, and supervision of ESS

installations within the city.

• Group R-3 occupancy includes which type of building?
• Commercial office tower
• Large apartment complex
• One- or two-family home
• Hospital

Rationale: R-3 occupancies include small residential buildings like 1- and 2-

family dwellings.

• An ESS installation must have signage that indicates: 2 / 4

• Manufacturer’s tax records
• Owner’s personal data
• Battery type and shutdown procedures
• Community board district

Rationale: Emergency responders must know the battery type, hazard

class, and shutdown directions.

• Lithium-ion ESS units present which primary hazard?
• Oxygen deficiency
• Electromagnetic interference
• Thermal runaway and fire
• Corrosion of soil

Rationale: Lithium-ion units can enter thermal runaway, leading to high-

heat fire events.

7. In an ESS fire, the supervisor should first:

• Attempt to dismantle the ESS
• Call 911 immediately
• Apply large amounts of foam
• Disconnect individual battery cells

Rationale: Immediate notification is required before any actions are

attempted.

• Who must perform maintenance on high-voltage ESS equipment? 3 / 4

• Any homeowner
• W11 supervisor
• Qualified technicians or authorized service providers
• General electrician apprentice

Rationale: Only trained personnel with proper licensing may service ESS

electrical components.

• What document must be available for responders at the installation?
• Birth certificate of the owner
• Tax assessment paperwork
• Emergency operations plan (EOP)
• Insurance policy

Rationale: The EOP provides critical information for safe emergency

mitigation.

10. ESS installations must be inspected:

• Once every five years
• Only after installation
• Regularly as required by FDNY and manufacturer
• Only after a fire

Rationale: Routine inspections ensure safe operation and compliance.

(For brevity of explanation here: You will receive all 100 questions.

Continuing now.)

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