Samardas
Member
- Location
- Los Angeles, CA, United States
- Occupation
- Electrical Engineer
Hi, a facility has an electrical room where a 600A disconnect switch is being tapped to install another disconnect (480V, 3 Ph, 225A) for primary protection of a 150KVA transformer. The transformer is located outside, ~400' away. Here are the questions: 1) Does it need another primary disconnect near the transformer? 2) Does the secondary need another protection via a disconnect near the transformer if a 400A panel next to the transformer already exists without a main CB (MLO)? I checked the NEC Article 450, which has both scenarios (with and without a protection on the secondary). Not quite sure which one would apply here since the Customer has the panel w/o a Main CB. Your early response will be highly appreciated. Thanks & Stay Safe!
