Non-Contact AC Voltage Detector (ET330)The Triplett ET330 Non Contact Voltage Detector can easily check for the presence of AC Voltage before working on a circuit. Read More > DESCRIPTION The Triplett ET330 Non Contact Voltage Detector can easily check for the presence of AC Voltage before working on a circuit. It has dual AC voltage ranges (24 to 1000V and 90 to 1000V) with high sensitivity that allows it to detect low voltage AC wiring commonly found in doorbell circuits, thermostats,