Siemens NXD N-Frame Sentron Circuit Breakers
The Siemens NXD series is an N-Frame 1200A Sentron molded case circuit breaker with non-interchangeable trip unit, rated for 600V and 85kA interrupting capacity. UL listed for reverse-feed applications. Available in 3-pole from 400A to 1200A.
Series Specifications
| Frame | N-Frame 1200A Sentron — 1200A Frame |
|---|---|
| Amperage Range | 400A – 1200A |
| Voltage | 600VAC |
| Poles | 3-Pole |
| Interrupting Rating | 85kA @ 480V |
| Mounting | Bolt-On |
| Trip Type | Electronic Trip |
History and Replacement Context
The NXD series features a non-interchangeable (fixed) trip unit, making it UL listed for reverse-feed applications per UL 489. Preferred for large main breaker and feeder applications in high-fault environments.
Typical Applications
- Large commercial main breakers
- Industrial switchboard mains
- Large feeder protection
- Service entrance equipment
- Reverse-feed applications