Statistical Characterization of Neutral Sensitivity in 50-Amp RV Shore Power Systems

Recreational vehicle (RV) electrical protection systems typically operate using threshold-based detection of over-voltage (OV) and under-voltage (UV) conditions, providing limited visibility into precursor behaviors that may indicate developing pedestal or neutral integrity problems.  Simple wiring issues, reversed line and neutral, and open ground are often also checked.  Intermittent neutral instability in split-phase RV park power systems can produce damaging voltage excursions that are difficult to diagnose using conventional event-only monitoring.

This paper presents a passive monitoring methodology for characterizing RV pedestal power quality using continuous time-series measurements obtained from a Shelly Pro 3EM energy monitor. Data are collected at 60-second intervals and processed through a Node-RED ingestion pipeline with PostgreSQL analytics to identify OV/UV events and compute precursor metrics, including a Neutral Drift Index (NDI) and voltage delta percentage (dv_pct). For each detected event, a five-minute pre-event context window is analyzed to evaluate potential leading indicators of voltage excursions.

Baseline observations across multiple park deployments demonstrate stable operating signatures under normal conditions, with low NDI variance and absence of significant voltage imbalance spikes. The proposed framework enables objective, park-attributed evidence collection and supports identification of measurable behaviors associated with developing voltage anomalies. While not intended as a predictive protection device, the approach provides enhanced forensic visibility into RV pedestal power quality and establishes a foundation for future multi-site correlation and early-warning research.