For what purposes are Electrical Clamps used? Types of Clamps

The device is distinguished by the presence of a pincer clamp located in the upper part of the device. This allows current and voltage to be measured in a non-contact manner. Some types of devices under consideration (for example, Fluke 325) can do more, for example, set the value of the current wire resistance in continuous mode. This facilitates troubleshooting and subsequent analysis.

A positive feature of current clamp meters is the ability to make measurements without disconnecting the diagnosed section of the circuit from the power supply. Unlike a standard digital multimeter, it is possible to measure all parameters for alternating and direct current without additional adjustments, although the reading accuracy will be lower.

1. A jaw clamp that is placed around the conductor.
2. A tactile barrier that protects the operator's fingers from possible electric shock.
3. A reading holding unit that fixes the value of the measured parameter on the display screen until reset.
4. A settings panel that allows you to change the number of characteristics to be determined and the measure of accuracy of the readings.
5. LCD screen.
6. Tick ​​release device (optional).
7. Compartment for installing a 9V power supply.

Among the control buttons are backlight, maximum-minimum button, and selection of other functions. Some models have USB input jacks for connecting third-party gadgets.

The geometric dimensions of the jaw grip vary from model to model, so to make the right choice, you should clarify what measurement range will be most often in demand.

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DC and AC current clamps: the main differences and how to choose the right one In order to measure a small current with a current clamp, you need to wind the wire on which you want to find out the current several times around an open magnetic circuit. Ask, I'm in touch!

How to use current clamps?

There are current clamp meters of analog and digital types. The first (in particular, Ts4505m) show the current value of the parameter, the second allows you to record the result on the screen and record it through a device connected to the connector. This is much more convenient when making multiple measurements.

The sequence of control of the current clamp when determining current readings is as follows:

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Built-in Chandelier

• Before turning on, you must disconnect all previously connected sensors.
• Select the required function on the control panel (the display should show the corresponding icon).
• Open the jaw grip of the electrical clamp and position it so that the desired section of the circuit is covered.
• Insert a current-carrying conductor into the gap.
• Close the jaw structure and align the conductor between the marks on the clamps. In some designs there are no marks, then the conductor is placed approximately in the middle.
• Read the readings on the LCD screen, and the resolution of the device is usually set automatically, depending on the actual values ​​of the parameter being tested.

For safety reasons, it is prohibited to use electrical clamps when working with uninsulated sections of wires. A number of the types of multimeters in question have the option of a flexible current probe, which allows them to be used when working in confined spaces.

1. The multimeter should only be used on one conductor, as otherwise currents flowing in opposite directions may throw off the reading.
2. It is imperative to use gloves with the appropriate level of electrical protection.
3. Before use, disconnect all previously connected probes.
4. Always place your fingers behind the tactile barrier.

For calibration it is recommended to use the “zero” function. It is especially important when measuring DC current because it eliminates possible offset in the readings.

Of the domestic analogues, the most functional are the M266 electrical clamps, which have such user-friendly functions as an audible signal, overload and battery charge indicators.

Recommendations for selection

To ensure that none of the workers subsequently becomes a victim of electric shock and the culprit of an accident at an electrical installation, adhere to the following recommendations.

• To purchase current clamps, contact a specialized electrical and electronics store, where experienced consultants will tell you which clamps are suitable for solving specific problems. Their experience can prevent mistakes, the consequences of which could be disastrous.
• First of all, decide what kind of current you will work with. AC/DC markers indicate that the tool is universal, DC is only for direct current on the line, AC is only for alternating current.
• Decide what power range you will be working in. Perhaps your choice is in circuits and lines with a maximum power of, say, up to 25 kW, then you are unlikely to need current clamps with a power of 500 kW if there is a product on sale for 50-100 kW.
• Decide what the diameter of the wires on which the power is measured is. Perhaps you will work on wires with a cross-section of up to 15 mm2, then you do not need larger pliers, where the cross-section size reaches 50-100 mm2, if the size on sale is 15-25 mm2.
• If we are talking about digital clamps or a device model for direct current, decide how it is more convenient for you to read the measured current: by reading in milliamps, millivolts or volts.
• Make sure that the materials of the insulating handles and the coating of the pliers do not conduct current. It should be high quality plastic, rubber or composite.
• Check the warranty service life of the pliers, make sure that in the instructions the manufacturer has indicated parameters whose value ranges include those that you need for safe and trouble-free operation.
• Refrain from purchasing pliers at too high a price - not all of their functions may be useful to you.
• If the work is mainly carried out in garage-domestic conditions, and not in production, then give preference to inexpensive pliers, from which you only need to successfully solve your specific problems. Pliers in a low price range are equipped with the function of testing lines and sections of chains.
• Avoid cheap Chinese counterfeits, which have a strong plastic smell. In some areas of the same clamps there may be extra gaps and cracks in the dielectric coating.
• If the seller has the opportunity to test the device with a current clamp, make sure that it does not exceed the stated error of the measured current, voltage and resistance in the test line.
• If you have to carry out measurements and tests in electrical installations around which there is excessive humidity, high or excessively low temperatures, choose a product that meets your specific needs.
• Focus on reviews from real customers. If you suspect that positive reviews may have been written at the request of the manufacturer itself in order to increase the rating of the product, look for reviews from other users on similar sites. Even the marketplace where you order these pliers will not provide a 100% guarantee of protection from unrealistic reviews.
• For thin wires, lightweight pliers are used. If your work does not involve contact of the device with a voltage of more than 220 volts, and the consumed currents hardly exceed 20 A, then use lightweight clamps, the cross-section of the wire soldered to the claws is equal to the ammeter shunt in a conventional multimeter.
• Make sure that the batteries in the digital device (to power the multitester) are easy and quick to replace.

Make sure the clamp device provides:

• measurement of current and voltage surges when starting powerful engines;
• automatic switching of measurement ranges, which saves time when taking measurements;
• if the display is large enough and backlit, this allows you to work on the line even at night.

Safety rules at work

Clamp meters may only be used indoors or outdoors in dry weather. The current can be measured both on cables covered with insulation and on bare ones. Before use, a person must wear protective gloves, place a dielectric base under their feet and wear special boots.

As a rule, using current clamps does not cause any particular difficulties. Before using the tool, you should pay great attention to safety precautions, as mentioned earlier.

How to use clamp meters correctly:

1. Set the required range on the switch.
2. Press the magnetic circuit opening button.
3. Encircle a single conductor in an AC or DC network (if such a possibility is supported by the device).
4. Position the current clamps perpendicular to the direction of the wire.
5. Take readings from the display.

You can clearly see how to work with current clamps in the video instructions below:

conclusions

All three devices work, all declared characteristics correspond to real ones.

ICartool IC-200A

Suitable for those who have a multimeter, but lack the function of checking the consumption of electrical appliances. Advantages: compactness and price. The disadvantages include the low quality of soldering.

ICartool IC-206В

– a device with balanced characteristics. Having such a device at home, a multimeter is no longer necessary. By and large, in order to become universal, it only lacks a current measurement function. But for this case there is another model.

ICartool IC-206D

- a universal device. Strengths – measures everything. Disadvantages - strange behavior in duty cycle measurements.

The advantages of all three devices

- good cases. Fairly accurate measurements. Rich functionality of older models.

Disadvantages of all three

– the dialing mode is not very convenient and the screen is not visible from all angles.
Topic: Current clamps

Types of execution

Dietz meters are divided into analog and digital:

• Analog meters. As a rule, they can only measure alternating current; readings are taken from the built-in ammeter. Such instruments were widespread before the advent of digital meters.

• Digital (most popular). An integrated circuit is installed inside such devices; as a rule, they have advanced functionality or additional functions of a multimeter (tester).

Specialized high-voltage electrical clamps

“Nowadays, with the development of technology, this method of measurement is practically not used due to the high risk of electric shock.”

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Operating principle and functionality For home use, inexpensive universal current meters, testers with a Hall sensor are better suited; such devices can fully replace a conventional multimeter in everyday life and are a must-have for every electrician. Ask, I'm in touch!

Design

In current clamp meters, two main working units can be specified:

Design of pliers

1. The grips contain the windings of the transformer.
2. The handle contains an ammeter or other measuring device.

An electric current is induced in the transformer windings, the characteristics of which are determined by a built-in measuring device. It must be taken into account that the induced current has a different value compared to the original one. To obtain an accurate value, a recalculation is required.

Measurement procedure

Before you start using the meter, read the user manual:

“Be sure to follow safety precautions when working with electric current and electrical equipment. Carefully study the rules for using the device described in the instructions.”

The main rule when measuring is that the current must be measured in one of the conductors. If insulated conductors are additionally combined into one wire, for example, a TV wire or a kettle wire, then the measurement result may be incorrect or zero.

1. For a more accurate result or to measure low current, if the conductor being measured allows it, make several turns around the clamp. Divide the resulting measurement result by the number of turns, as a result you will receive a revised measurement value.

Useful tips Connection diagrams Principles of operation of devices Main concepts Meters from Energomer Precautions Incandescent lamps Video instructions for the master Testing with a multimeter

Device

As mentioned earlier, the mechanism of operation of clamps is based on the principles of a transformer current, which consists of a primary (usually a bus or wire) and secondary windings. The meter is connected to the secondary winding, which must be located on a detachable magnetic circuit. The wire around which the clamps are closed creates an alternating magnetic field around it, invisible to the human eye, which is measured by the device.

Based on the design, there are 2 types of current clamps: simple (a) - their operation is based on the operating principle of a single-turn transformer; complex (b) - they have a rectifier in their functionality, and their operation is also based on a single-turn transformer.

Device design

It is worth paying special attention to the picture diagram: it shows and marks the components of current clamps. So, number 1 on it directly indicates the wire that is being measured; number 2 - these are detachable cores (pincers); number 3 indicates the winding (secondary); number 4 is a built-in rectifier; number 5 is an image of a measuring frame; number 6 - drawing of the lacing resistance; number 7 indicates the toggle/mode switch; number 8 is the bracket (lever).

This diagram presented a very detailed internal structure of a clamp meter. However, it can be said that current clamps actually consist of three parts:

• Working: directly the clamps themselves and the magnetic circuit.
• Insulating: the space between the handle and the working part.
• Handle bodies.

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