What Is a Leakage Clamp Meter?
A leakage clamp meter is a type of clamp meter that is mainly used to measure and detect leakage currents. In addition to leakage current, some types can also measure load current.
Leakage currents adversely affect circuits. As a result, leakage clamps are used to measure and detect leakage currents for preventive maintenance.
In particular, by utilizing the features of clamp meters to measure current by clamping electric wires, insulation control can be easily and safely performed during live wire work (inspection and maintenance work while voltage is applied) without disconnecting the power supply and without unraveling the wires and cables.
Uses of Leakage Clamp Meters
Leakage clamp meters are used to measure leakage currents for the purpose of diagnosing and preventing electrical shock accidents and equipment malfunctions caused by poor insulation.
There are models dedicated to AC (alternating current) or DC (direct current) circuits to be measured, as well as dual-use models. Some are equipped with a digital display, while others are capable of sampling (extracting measurement time and measured values as data) as digital values at regular intervals and recording events in memory.
Recently, there are also types that can transfer data using Bluetooth wireless communication, allowing for easy data organization and analysis on a PC.
Principle of Leakage Clamp Meters
Leakage clamp meters are measuring instruments for measuring and detecting leakage current. What sets them apart from normal clamp meters is their capability to measure and detect minute leakage currents in the unit of mA.
Leak current refers to the current that leaks out from insulated areas in electrical and electronic circuits, where normally no current would flow. This leakage current adversely affects circuits, causing malfunctions, increased power consumption and heat generation, and other performance degradation. As a result, it is necessary to detect and deal with leakage current.
The structure of leakage clamp meters roughly consists of the following two components:
- Clamp: A C-shaped lever with a built-in magnetic core opens and closes to clamp wires. The diameter of the clamp is wide enough to clamp and measure not only a single wire but also many wires at once.
- Housing: The housing has a built-in circuit for outputting numerical values of the measured current, a range selection switch, and a display for showing the measurement results.
The performance of leak clamps is specified in the international standard IEC/EN 61557-13, and some products comply with this performance standard.