How to measure motor current with a multimeter?

Estimate the current size to choose the applicable multimeter, the multimeter select the highest AC current level, the multimeter pen is connected to one of the power cords like a switch, the red one is connected to the power supply end, and the black pen is connected to the load end. It is convenient to have a clamp meter.

Generally, the multimeter has two measurement current gears, one is 20mA, the other is 20A, when measuring, the two meter pens of the meter are connected in series in the measurement loop, and the current size of the measured loop should be judged before measuring, but it exceeds the measurement range of the multimeter, otherwise the multimeter will be burned.

The multimeter is set with an AC current file, one of the motors is connected to the power cord and disconnected, the two ends of the disconnection are connected to the meter and connected in parallel at both ends of the meter in a closed state, and the switch is turned off after the motor starts, and the meter indicates the current value.

In a circuit with an electric motor, let the motor work properly! A galvanometer is connected in series in the circuit and reads. Don't use Ohm's law!

Ohm's law only applies to purely resistive circuits, motors are non-purely resistive! How to connect in series? Positive receives negative!

The whole circuit is one line!

It can only be measured in one phase and one phase, and it can be disconnected in series with one phase, and it is necessary to pay attention to the highest AC gear, and the motor current can not exceed the maximum current range.

It is more convenient to measure with a clamp flow meter.

It's more troublesome, and if you don't get it, it will burn. Why don't you borrow a clamp watch?

1. The gear should be consistent with the type of current to be measured. That is, according to the type of AC and DC of the current you want to measure, choose the correct gear, AC corresponding to AC gear, DC corresponding to DC gear.

2. Choose the appropriate range, otherwise, it is very likely to lead to the burning of the multimeter. If you do not know the size of the current to be measured, you should choose the maximum range. For example, a digital multimeter with a 20 amp range can measure the current of kilowatt electrical.

3. Connect the multimeter in series on the live line of the electrical appliance. To do this, the first step is to disconnect the electrical switch. The second step is to unplug the plug and connect the meter in series; The third step is to plug in the plug and close the switch. At this point, the reading of the multimeter is sought.

Note: It is dangerous to use this method to measure the current of high-power electrical appliances, and it is easy to burn the meter. It is recommended to use a clamp ammeter. This makes it safe and easy to do.

Measurement of DC current.

Insert the black watch pen into the "com" hole first. If the current is greater than 200mA, the red watch pen should be inserted into the "10A" jack and the knob should be turned to the DC "10A" gear; If the current is less than 200mA, insert the red watch pen into the "200mA" jack and hit the knob to the appropriate range within 200mA DC.

Stay stable and you can read. If it is displayed as "1.".", then it is necessary to increase the range; If a "-" appears to the left of the value, it indicates that current is flowing from the black pen to the multimeter.

2. Measurement of alternating current. The measurement method is the same as 1, but the gear should be hit to the AC gear, and the red pen should be inserted back into the "V" hole after the current measurement is completed.

Hello! How do I measure motor current with a multimeter? 1. When the multimeter is used, first of all, we need to be careful not to start using it immediately, and we must change the operation of mechanical zeroing first.

That is to say, before the measurement is made, the pointer needs to be adjusted to the position of the zero voltage, so as to ensure the accuracy of the measurement. 2.During the measurement process of the multimeter, it is forbidden to touch the pen with your hands, especially the metal part, because this will affect the accuracy of the measurement.

In addition, if you touch it unexpectedly, you may be at risk of electric shock. 3.When measuring a certain current with a multimeter, do not change gears before the measurement is finished, especially when measuring high voltages.

Otherwise, not only is it easy to damage the multimeter, but it may also be dangerous. If you need to change gears, you must disconnect the watch pen first and then go to the shift measurement. 4.

The multimeter should be kept in a horizontal state during measurement, otherwise the measured results are prone to errors. In addition, it should also be noted that items with strong magnetism should not be placed around the vertical multimeter, because this will affect the accuracy of the measurement. When the measurement is complete, the battery needs to be removed and stored.

Summary. After using the multimeter, adjust the transfer switch to the maximum setting of AC voltage. If you have not used the multimeter for a long time, you need to remove the installed battery to avoid the battery from corroding the parts of the instrument.

Before using the multimeter, it is necessary to estimate the range of voltage and current, first adjust to a relatively large gear, and then adjust to the appropriate gear, so that it is not easy to burn out the multimeter.

The multimeter for measuring motor current with a multimeter should be connected in series with the circuit under test, and the multimeter should be connected to both ends of the power-off after the circuit correlation plexus ruler part is disconnected. Depending on the amount of current in the circuit, the range is selected. If you do not know the size of the current, you should choose the maximum range.

The red pen should be connected to the breakpoint connected to the positive pole of the power supply, and the black pen should be connected to the negative pole of the power supply.

What gear is the multimeter in.

Measure the motor current or something else.

After using the multimeter, the transfer switch should be adjusted to the maximum level of AC voltage. If you have not used the multimeter for a long time, you need to take out the installed battery to prevent the battery from corroding the parts of the instrument. Before using the multimeter, it is necessary to estimate the range of voltage and current, first adjust to a relatively large gear, and then adjust to the appropriate gear, so that it is not easy to burn out the multimeter.

Amount of motors. Measure the current to see what kind of current it is, if it is DC, then hit the A-gear, if it is AC, then hit the A gear, insert the red pen into the MA or A jack, and insert the black pen into the common section of the COM hole, and then connect the pen in series to the circuit, first disconnect the tested circuit from the Qingpei nucleus, and then connect the pen into series.

AC 22 kW motor.

The universal watch was sent over to take a look.

A gear. 200 here.

Teacher, is the red one plugged in the 10a?

What is the resistance value of each phase sequence and the common potato blind point (and u1 and u2 v1 and v2 w1 and w2): the method is the same as in step 2. If the three results of the measurement are the same, it means that there is no problem with the phase circuit, and the leakage proves that the motor is good.

The black line and the red line are reversed, and the hole is wrong.

Teacher! I asked the red one to be inserted in **ah.

Corresponding to the diagram on it.

It's not responding, or it's broken.

Summary. 3-phase asynchronous motor multimeter measurement method: a total of 3 parameters 1:

Measure the insulation resistance of the windings and the casing. Method: The multimeter hits the maximum range of ohms, one watch pen is connected to the casing, and the other watch pen is connected to one of the phase windings, and each phase is measured in turn.

The measured resistance should be infinity. 2: Measure the insulation resistance between phases.

Method: When the multimeter reaches the maximum range of ohms, the two meter pens are connected to two phases respectively, and the resistance of each phase is measured alternately, and the measured resistance should be infinity. 3：

Measure the phase resistance. Method: The gear is still in ohms, and the gear size is different according to the different motor resistance values, which can be tested from large to small.

Two pens are placed at each end of a phase to measure each phase in turn. The resistance of each phase is measured to be equal. Remarks:

Remove all lugs and wires before measuring.

How to measure the input voltage of a motor with a multimeter.

1. State branch 220V AC input, the range to the intersection and closure of the current 500V, the car measurement pen input, the reading is the input voltage V AC input, the range is AC 500V, the measurement pen is connected to any two lines at the input end, the reading is the input voltage. 3. DC input, hit the range to the DC voltage level, and the voltage should be higher than the measured voltage. 500v

Use a multimeter to measure the input voltage of the motor. In the normal operation of the motor, the voltage level of the multimeter (DC gear for DC motors, AC gear for AC motors) can be connected to the power input terminal of the motor. Debate brother.

Multimeter measurement method of 3-phase asynchronous motor: a total of 3 parameters are measured: 1: measuring the insulation resistance of the winding and the casing.

Method: The multimeter hits the maximum range of the ohm file, one watch pen is connected to the casing, and the other watch pen is connected to one of the phase windings, and the phase is measured in turn. The measured resistance should be infinity.

2: Measure the insulation resistance between phases. Method:

When the multimeter hits the maximum range of the ohm file, the two meter pens are connected to the two phases respectively, and the resistance of each phase is measured alternately, and He Jingzheng measures the resistance to infinity. 3: Measure the phase resistance.

Method: The gear is still in ohms, and the gear size is different according to the different motor resistance values, which can be tested from large to small. Two pens are placed at each end of a phase to measure each phase in turn.

The resistance of each phase is measured to be equal. Note: Remove all connecting pieces and guide lines before measuring.