How Do You Use a Current Clamp?

A current clamp is an electrical instrument that measures the number of amperes flowing through a conductor. It works in place of a multimeter under specific circumstances. These include cases where it is unfeasible to cut the live power supply to the system. It can also come into use when the value of the current is too high and hazardous.

Current clamps use their jaws to clamp around the outer surface of the electrical conductor. They proffer non-contact quantifications and assessments of resistance, capacitance, continuity, voltage, and so on.

Principle of a Current Clamp

A current clamp works on the principle of electromagnetic induction. It states that when a current passes through a conductive material, a magnetic flux gets generated in it. The device has two clamps composed of ferrite iron. They come with copper coils wound around them. Together, they create the magnetic core that takes the measurements in actuality. The instrument primarily uses hall elements as a sensor to sense and detect the direct and alternating currents. Hall elements are semiconductors used to generate voltage in a conductor. This voltage is proportional to the product of the output terminal’s magnetic field and the bias current. The bias current gets infused into the input terminal. Hence, when a magnetic flux proportional to the direct and alternating primary currents gets formed in the transformer, the hall elements perceive the magnetic flux and determine the output voltage.

Operation of a Current Clamp

Current clamps that work on alternating current operate in the same manner as a current transformer. When the current flowing through the conductor is the primary one, it is possible to acquire a secondary current proportional to its counterpart through electromagnetic induction. It gets formed from the area of the secondary winding connected to the instrument’s measuring circuit. After the coil receives the current flow, the components of the current clamp take the reading of the alternating current and present it on the display screen.

What Do the Buttons of a Current Clamp Represent?

Each button of a current clamp represents a particular function. A few of them entails:

• Hold: It freezes the readings on the display screen. On pressing the button a second time, the fixed values get released and move on to the next ones.
• Min-Max: On pressing the button the first time, the maximum input value gets shown. With succeeding pushes, the average and minimum inputs get displayed.
• ZERO: It removes the DC offset from the direct current measurements.
• Range: It permits the users to switch the feature from auto to manual. It helps them set the extent of quantification.
• Log: It initiates the process for recording the data.
• AC/DC: It allows a shift between the alternating and direct currents and their measurements.
• Beaming Orb: It switches the display backlight off or on.
• Low Pass Filter: It eliminates the surrounding and environmental electronic disturbances. They can otherwise interfere and distort the measurement and readings.

What is the Correct Way to Handle and Use a Current Clamp?

The method of handling and utilizing is exceedingly effortless and secure. The user merely needs to fix the clamps of the device on the conducting material. They include wires, pipes, rods, and so on. The hinges present in the instrument permit the clamps to open and close whenever the current measurements need to get taken. The current clamp performs its share of the working and presents the measured data and values on the display. The users need to read this information and interpret them as necessary.

For direct current measurements, the correct way that an individual should follow comprises the following:

• Setting the rotary switch to DCA.
• Pushing and holding the button for DCA ZAERO till the readings come down to and display zero.
• Pressing the trigger or switch to open the jaws of the instrument and clamping the target conductor. It is imperative to ensure that there is no air gap between the two halves of the jaws.
• Selecting a range of quantification if necessary by pressing the button for it before the DCA ZERO button.
• Reading the presented value on the display or LCD.

For alternating current measurements, the correct way an individual should follow comprises the following:

• Setting to the rotary switch to ACA.
• Since the ZERO option is unnecessary, there is no need to press the button for DCA ZERO.
• Pressing the trigger or switch to open the jaws of the instrument and clamping the target conductor. It is imperative to ensure that there is no air gap between the two halves of the jaws.
• Selecting a range of quantification if necessary by pressing the button for it before the DCA ZERO button.
• Reading the presented value on the display or LCD.

How to Read the Display of a Current Clamp

The users of a current clamp generally work with an oscilloscope to read and understand its displayed values. For the RMS and DC readings, merely a digital voltmeter is sufficient. The other feasible and useable devices consist of:

• Datalogger
• Analog to digital converter (ADC)
• Power analyzer

To connect a current clamp to a data logger or an oscilloscope, an individual needs to follow the subsequent steps:

• They have to set the rotary switch to DCA or ACA.
• Then, they need to get the analog signal. It comes out as the output from the base terminals simultaneously. This output is directly proportional to the measured current in the unit of mV/A.
• The positive terminal gets represented by the red color, and the negative terminal, the black one.
• The users need to connect the negative and positive terminals to the data logger or the oscilloscope.
• Lastly, they have to observe and note the form of the current wave or go for a long-term recording of the data.

Uses of a Current Clamp

A current clamp is an exceedingly convenient and beneficial instrument that finds application in various domains, sectors, industries, and fields. They get used in and for residential, commercial, electrical, and industrial devices and appliances.

Primarily, a current clamp gives its service for the following purpose:

• To fix and restore existing electrical systems without cutting off the live power supply to the conducting devices and materials.
• To perform and execute maintenance and troubleshooting on faulty appliances or those susceptible to succumbing to damage and hazards.
• To accomplish installations and check their issues.
• To supervise circuit tests and electrical works.
• To measure the flowing current on the separate and individual circuits and connections at the distribution panel.
• To calculate and estimate the interference and leaks in the range of EMC (Electromagnetic Compatibility)