Siemens HMD M-Frame Hi-Break Circuit Breakers
The Siemens HMD series is an M-Frame 800A Hi-Break molded case circuit breaker rated for 600V and 65kA interrupting capacity at 480V. Available in 3-pole configuration from 300A to 800A for large commercial main breakers and industrial feeder protection.
Series Specifications
| Frame | M-Frame 800A Hi-Break — 800A Frame |
|---|---|
| Amperage Range | 300A – 800A |
| Voltage | 600VAC |
| Poles | 3-Pole |
| Interrupting Rating | 65kA @ 480V |
| Mounting | Bolt-On |
| Trip Type | Electronic Trip |
History and Replacement Context
The Siemens HMD Hi-Break series provides higher interrupting capacity than the standard MD frame for large main breaker applications in high-fault environments.
Typical Applications
- Large commercial main breakers
- Industrial feeder protection
- Switchboard applications
- Motor control center mains