Product Description

100A AC Current Transformer (CT)

1000:1 Ratio, 1.5% Accuracy, 12″ Leads

If you want to measure AC current (amps) on your boat, you need a current transformer. This 100A AC Current Transformer (CT) is designed to work with the DEX7 Marine Multimeter to accurately measure AC current draw from shore power or a generator.

Unlike DC current measurement, AC current cannot be measured using a shunt. A current transformer allows the DEX7 to measure AC amps safely and accurately without running high current through the meter itself.

What Does a Current Transformer Do?

A current transformer (CT) is a doughnut shaped sensor that goes around a single AC conductor (either hot or neutral). As current flows through the wire, the CT produces a small proportional current that the DEX7 reads and converts into a real-time AC amperage display.

• No high current passes through the DEX7.
• The CT safely measures current without adding resistance to the circuit.

Built for Accurate AC Monitoring

This CT features a 1000:1 ratio and 1.5% accuracy for stable, repeatable readings. It has no internal burden resistor, making it compatible with meters designed to handle the burden internally, including the DEX7.

This is the ideal sensor for monitoring:

• Shore power current draw
• Generator load
• AC system usage
• Inverter AC output (where applicable)

Why Monitor AC Current?

Most boats have no way to see real-time AC current draw. Monitoring AC amps allows you to quickly verify system load and identify issues before breakers trip or wiring overheats. It is also one of the easiest ways to confirm that shore power is working correctly and that onboard AC loads are operating as expected.

Technical Specifications

• Rated Primary Current: 100A
• Ratio: 1000:1
• Accuracy: 1.5%
• Burden: No internal burden resistor
• Lead Length: 12″
• Outer Diameter (OD) max: 1.16″ (30mm)
• Inner Diameter (ID): 0.49″ (12.5mm)
• Compatibility: DEX7 Multimeter

Installation Notes

• Disconnect the AC line (hot/ungrounded) conductor and pass it through the center of the CT.
• The direction the conductor passes through the CT does not matter.
• Do NOT pass both hot and neutral through the CT. Their magnetic fields will cancel, resulting in little or no current reading.
• For jacketed multi-conductor cable, the individual conductors must be accessible so that only one current-carrying conductor passes through the CT.
• Do NOT operate the circuit with the CT secondary leads disconnected from the meter. If operation is necessary while disconnected, short the CT secondary leads together first.
• Route CT leads away from high-noise wiring when possible.