Technical guide on using Cummins PowerCommand® AmpSentry for short‑circuit and arc‑flash studies in SKM software.
This application note explains how to model a generator set with the Cummins PowerCommand® AmpSentry over‑current protection feature in SKM Power Tools. It describes the steps to enter generator data, configure the AmpSentry component, and set arc‑flash calculation parameters.
The paper also demonstrates the impact of AmpSentry’s maintenance mode on arc‑flash incident energy, showing a reduction from 75.2 cal/cm² to 19.5 cal/cm² in a simple example. Labeling requirements and safety considerations for maintenance mode are discussed, along with author credentials.
| Current regulation limit | 300% of generator set rated current |
|---|---|
| Maximum arc duration (normal operation) | 2 seconds |
| Arc flash incident energy reduction (example) | 75.2 cal/cm² → 19.5 cal/cm² |
It meets NEC 240.87 arc‑flash mitigation requirements and reduces incident energy by shutting off the generator within 50 ms and using the alternator transient time constant.