Inside Electrical Room



Clearance

NEC 110.26(E) requires a minimum clearance of 3 feet in front of and below suspended transformers.

Mounting

Transformers must be securely mounted to the ceiling or other supporting structure (NEC 450.11(B)).

Conductor Protection

Conductors must be protected from physical damage and supported in accordance with NEC Chapters 3 and 4 (NEC 450.10(A)).

Ventilation

Transformers must have adequate ventilation to prevent overheating (NEC 450.11(B)).

Access to Terminals

Terminals must be accessible for inspection and maintenance (NEC 450.10(A)).

Outside Electrical Room



Enclosures

Transformers must be enclosed in a weatherproof enclosure if located outdoors (NEC 450.11(C)).

Ventilation

Transformers must have adequate ventilation to prevent overheating, even if enclosed (NEC 450.11(B)).

Marking

Enclosures must be clearly marked "Transformer" (NEC 450.11(C)).

Access to Terminals

Terminals must be accessible for inspection and maintenance (NEC 450.10(A)).

Additional Considerations



Fire-Resistant Materials

Transformers must be installed in areas where they will not be exposed to fire hazards (NEC 450.11(B)).

Grounding

Transformers must be properly grounded (NEC 250.21).

Overcurrent Protection

Transformers must be protected by overcurrent devices (e.g., fuses or circuit breakers) in accordance with NEC Article 240 (NEC 450.3).*

Capacity: Transformers must not exceed their rated capacity (NEC 450.2). Flag for review