Certain aspects and features include a system and method for monitoring the operational status of assets in an electric power distribution system. For example, an asset monitoring system identifies a zone of operation for an asset under evaluation. The asset monitoring application identifies meters connected to transformers in the zone of operation and obtains meter voltages for the meters over multiple intervals. The asset monitoring application determines a primary voltage for at least one transformer based on at least one meter voltage. The asset monitoring application uses the primary voltage in a power flow calculation to estimate an operational setting for the asset. The asset monitoring application compares the voltages from the power flow analysis using the estimated operational setting and the voltages from the meter voltages across multiple time intervals. Based on the comparison, the asset monitoring application determines an operational status of the asset.