Electric Motor Testing With Multimeter

Power supply test for single phase motors the expected voltage is about 230v or 208v depending whether you are using the uk or america voltage system.

Electric motor testing with multimeter.

Klein tools multimeter test kit contains mm300 manual ranging klein tools multimeter test kit contains mm300 manual ranging digital multimeter ncvt 1 non contact voltage tester and the rt105 receptacle tester. Since there are three terminals. On the plus side the only items needed to perform the test is an electrical schematic of the motor along with a multimeter. This tester is capable of providing diagnostic information for all sorts of motors.

If you have a reading and your motor isn t operating it s certain the motor is the problem and needs replacing. Check the multimeter measurement. Test electric motor windings when a bad motor winding cannot be found by a physical inspection many times an ohmmeter may show that there is a defective winding. As you probably know fan motors can be designed for several different purposes most common of these are single phase motors.

In this video we show different tests 180 degrees test bar to. The ncvt 1 automatically detects standard voltage in cables cords circuit breakers lighting fixtures switches outlets and wires. The drawback of a winding test is that you will need to disassemble the motor. Each winding leg should have some small resistance.

If there is any reading on any of these then the motor is bad do not use it. Preliminary often definitive tests generally take place using the ubiquitous multimeter. You should perform this test whenever you see cracks or burn marks or you ve noticed a burning odor coming from the motor. You may find that when it runs ungrounded that the casing becomes live at up to supply voltage.

With a multimeter set to low ohms usually 200 test between each winding terminal and the metal casing of the motor. When an electric motor is broken one suspect is the armature with commutator of the motor. It can sometimes be very confusing to test fan motors for people who don t have much experience. Consult the motor schematic or a diagram of the motor s windings and use the meter to measure the resistance of the windings.

If the motor is completely unresponsive no ac humming or false starts take a reading at the motor terminals. A dmm digital multimeter such as this keithley dmm7510 from tektronix is a must have instrument for motor testing. A wide range of dmms are available to measure voltage current and resistance depending on the motor power ratings. Check that the correct voltage is applied to the motor.

It measures the same or similar to the voltage you noted from the label on the electric motor if power is reaching the motor.