How to use the clamp meter, the specific use of the clamp meter

The current measurement part of the clamp multimeter is composed of the current transformer and the current measurement part of the multimeter. The core of the transformer has a movable part and is connected to the handle, and the handle is pressed to open the movable core when in use. Put the wire to be measured current into the jaws, release the handle and close the core.

At this time, the wire passing through the current is equivalent to the primary winding of the transformer, and the secondary winding will induce current, the size of which is determined by the ratio of the working current of the wire and the number of windings. The ammeter is connected to both ends of the secondary winding, so the current it indicates is the current in the secondary winding, which is proportional to the current in operation.

Therefore, the calculated scale is used to reflect the amount of current on the primary side, and when there is current passing through the wire, the pointer of the ammeter connected to the secondary winding is deflected proportionally, indicating the value of the measured current.

There are two types of clamp ammeters, high and low voltage, which are used to directly measure the current in the line without disconnecting the line. Its usage and precautions are as follows:

When using a high-voltage clamp meter, attention should be paid to the voltage level of the clamp ammeter, and it is strictly forbidden to use a low-voltage clamp meter to measure the current of the high-voltage circuit. When measuring with a high-voltage clamp meter, it should be operated by two people, and the second type of work ticket should also be filled in by non-duty personnel for measurement, and insulating gloves should be worn during measurement, standing on the insulating pad, and other equipment should not be touched to prevent short circuit or grounding.

Special attention should be paid to maintaining a safe distance between the head and the charged part, and the distance between any part of the human body and the charged body shall not be less than the entire length of the clamp watch.

When measuring on a high-voltage circuit, it is forbidden to use a wire to connect a clamp ammeter to another meter for measurement. When measuring the current of each phase of the high-voltage cable, the distance between the cable heads and wires should be more than 300mm, and the insulation should be good, and it can only be carried out when the measurement is considered convenient.

When measuring the current of low-voltage fusible fuse or horizontally arranged low-voltage busbar, each phase fusible fuse or bus should be protected and isolated with insulating material before measurement to avoid causing interphase short circuit.

When the cable has a phase grounded, it is strictly forbidden to measure. Prevent the occurrence of ground breakdown** due to the low insulation level of the cable head and endanger personal safety.

After the clamp ammeter is measured, pull the switch to the maximum range to avoid accidental overcurrent during the next use; and should be kept in a dry room.

1. Clamp meter (sometimes called clamp meter, clamp meter) AC and DC clamp meter is also one of the necessary test tools in daily maintenance work, mainly used to test voltage, current, frequency and other related parameters, requiring it to have high test resolution, test accuracy and more test functions.

2. The connected ammeter will have an indication --- measure the current of the line to be measured. The clamp meter can be changed to different ranges by switching the switch gear. However, live operation is not allowed when dialing. Clamp tables are generally not very accurate, usually.

Level. For ease of use, there are also transfer switches of different ranges for measuring different levels of current and voltage.

3. The jaws should be closed tightly during the measurement, if there is noise after closing, the jaws can be opened and closed again, if the noise can not be eliminated, the joint surface on the magnetic circuit should be checked whether it is smooth and clean, and it should be wiped clean when there is dust.

(1) Mechanical zeroing should be done before measuring.

2) Select the appropriate range, choose the large range first, then the small range or look at the nameplate value estimate.

3) When the minimum range measurement is used, and its reading is not obvious, the measured wire can be wound around a few turns, and the number of turns should be subject to the number of turns of the jaw**, then the reading = the indicated value of the range full deviation turns.

4) After the measurement, place the transfer switch at the maximum range.

5) When measuring, the measured wire should be at the first of the jaws, and the jaws should be closed tightly to reduce the error.

Let's take a look at the specific use of clamp meters, the measurement of leakage current, and the introduction of filtering functions.

First of all, according to the size of the measured current, adjust to the appropriate gear, then open the jaws of the clamp ammeter, clamp a motor load line, pay attention to the amount of a single one, do not clamp two, and then remember the reading, and then measure the other two, and finally see whether the three readings are the same, you can determine whether the current size and the three-way current is balanced.

Some of the commonly used digital clamp meters are as follows:

1. AC current measurement.

Turn the switch to the ACA1000A to stop the gods.

Keep the switch in a relaxed state.

Press the trigger to open the jaws and clamp one wire, if more than two are clamped, the measurement is invalid.

Read the value, if the reading is less than 200A, the switch is turned to ACA200A to improve the accuracy, if due to environmental conditions, such as the dark place can not be read directly, press the hold button, get to the bright place to read.

2. AC and DC voltage measurement.

When measuring DC voltage, the switch is turned to ACA200A, and when measuring AC voltage, the switch is turned to ACV750V.

Keep the switch in a relaxed state.

Red table pen joint"v/ω"End, black table pen joint"com"End.

The red and black pencils are connected in parallel to the line under test.

3. Resistance measurement.

The switch is turned to a resistor of the appropriate range.

The Hoshino holding switch is in a relaxed state.

Red table pen joint"V-end, black rod joint"com"End.

4. On-off test.

Open the suspicion and shout to turn off to 200n gear.

The red and black watch pens are connected separately"v End journal com"End.

If the resistance between the red and black watch pens is less than (50 ±25), the built-in buzzer will sound.

1-pliers, 2-pliers, trigger, 3-hold-on-switch, 4-rotary switch, 5-display, 6-insulation test, accessory interface, 7-common ground, 8-voltage resistance, input 9-carry belt.

5. High-resistance measurement.

Screw the switch to"externalunlt"20m or 2000m gear.

The displayed value is unstable and in a free state.

Test Accessory: 3 plugs are plugged into the 3 input jacks of the clamp meter.

The clamp meter switch and the test accessory range switch are all placed at the 2000m position.

The test accessory input is terminated with the resistor under test;

Test accessory power supply into:"on"position, press"push"button, the indicator light is on, then the display shows the measured value, if the reading is less than l9m, the range of the clamp meter test accessories are selected 20m to improve the accuracy.

What is a Clamp Meter?

A clamp meter is essentially a combination of a current transformer and an ammeter, and it is a meter used to measure the magnitude of the current of an electrical line in operation, which can measure the current without interruption. Its working principle is based on the working principle of the current transformer, when the wrench of the clamp meter is tightened, the core of the current transformer will be opened, then the current of the measured wire will enter the jaw as a winding, when the wrench is relaxed, it will be wound again and then induce current, and then the current pointer will be deflected to display the value of the current.

The brand of the clamp meter

Imports are: Fluke of the United States, CA of France, Agilent of the United States, Yokogawa of Japan, etc.

Domestic ones are: Taiwan Taishi, Taiwan Qunte, Huashengchang CEM, Shengli Instrument, etc.

Selection of clamp meters

Function selection: Generally, it is to measure the current, the current is divided into DC and AC, and the voltage, resistance and diode are also measured.

Test range: mainly the range of test current, generally in 200A, 400A, 600A, 1000A, 2000A, larger in 3000A or more, the voltage is generally between 60V-100V.

Clamp gauge size: The caliber size of the clamp gauge must be determined and selected according to the specification of the conductor to be measured.

Clamp meter models: 2006, 2004, 2002PA, 2003A, 2009A, 2010F312, F316, F318.

How to use the clamp meter

1. Before use, you must carefully read the instruction manual to find out whether it is AC or DC, or AC and DC.

2. The voltage of the circuit to be tested cannot exceed the value indicated on the clamp meter, otherwise it will cause an electric shock accident.

3. Before measuring the clamp meter, the size of the measured current should be estimated first, and then decide which range to use. If this is not possible, the maximum range can be measured first, and then the range can be adjusted appropriately according to the transformation of the value for a more accurate reading. In order to avoid damaging the instrument, it is not possible to measure large currents with small currents.

4. The jaws should be tightly closed during measurement, if there is a sound after closing, it must be closed again, if the sound can not be eliminated, it is necessary to check whether the joint surface on the magnetic circuit is clean, and if there is dust, it should be wiped clean in time.

5. During maintenance, the power should be cut off to prevent electric shock.

Conclusion: After reading this article, do you have a certain understanding of the clamp meter, if the home appliances are broken and need to be repaired, you must understand these ways to use, so as to avoid unnecessary trouble.

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