July 14 2025 #260 - Generator Inrush, Field Day Logging | W3GMS Workbench

W3GMS Monday Night Workbench Net

Host: KC3NZT

🔧 General Discussion Highlights

• Field Day Aftermath & Logging Success
  WA3VEE and several others (including KC3OOK, W3KZG) recapped an intense six-hour post-field day session at WA3LVR’s home. Final logs were reconciled and submitted to ARRL. Participation reached a record: 34 operators, 31 visitors, 8 youth, and 100 contacts logged on K3DTS.
• Generator Inrush Lessons
  A lively, deeply technical discussion centered around an electric woodchipper rated at 5 HP, 230V, and requiring a 30–40A breaker, yet showing a startup current of 142 amps. Multiple ops shared field experience and technical insights, including:
  • Why household breakers can tolerate short-duration surges
  • Differences between American thermal-magnetic vs. European magnetic breakers
  • Importance of proper wire gauge for protection (per NEC)
  • Tips for generator use, including the infamous “bump start” technique
• Rotator Mounting & Wind Load
  Wayne (KC3SQI) asked about mounting a thrust bearing on unistrut and rigid conduit to support a 25–30 lb antenna. Advice emphasized:
  • Maintaining solid alignment between rotator and bearing
  • Using heavier-duty rotators (like Yaesu G-800 over G-450)
  • Considering wind load and moment arm, even for a compact hex beam

❓Technical Questions

1. CR – Circuit Breaker for 230V Equipment
   • Concerned about a chipper with 5HP motor and required starting amps of 142A
   • Got feedback on magnetic vs. thermal-magnetic breakers, wire safety limits, and starting behavior on generators
2. KC3SQI – Mounting Thrust Bearings on Mast
   • Query about using unistrut off a 1.5" rigid conduit mast
   • Recommended: strong, rigid bracketing with precise alignment and considering future rotator strain