Motor manufacturers try their best to match an off-the-shelf motor or gearmotor to specific customer requirements. Sometimes a perfect match can be made; however, it is often the case that a custom solution is needed or that the customer’s capabilities are not known and a physical motor needs to be tested to determine the unique requirements. If this is the case, some level of motor testing has either already been performed or will need to be done.

Speed/Torque Test

The most basic level of motor or gearmotor testing that is performed is a Speed/Torque Test. This test is performed by coupling the test motor to a dynamometer. The test starts with zero torque load on the motor shaft and the rotational speed is measured at increasing torque loads until a curve is generated. The input power is also measured during this test. From this test the output power, watt losses, and efficiency values can be determined for each given speed/torque point.

Temperature Test

Another very important test that is also often performed is the Temperature Test. This test is useful for determining the ratings for a particular motor. Performing this test requires the same equipment as the Speed/Torque Test with the addition of a temperature measuring device (such as a thermocouple or thermistor) placed on the motor windings. A specific load is applied to the motor and the winding temperature is recorded. The load is adjusted until the desired steady state temperature is achieved. This effectively tells us the performance that a given motor will provide when continuously operated at full load. Running at a lower load will ensure safe operation. Applying higher loads to the given motor should only be done intermittently as to prevent overheating. If an intermittent duty specification is known further testing at Groschopp can be performed to effectively determine the correct motor size.

Using the data from these tests can usually give us a good indication if a certain motor will perform at a desired level. In addition to these two tests many of our off-the-shelf motors and gearmotors have also been subjected to numerous other tests such as rotor inertia, back EMF, inductance, thermal time constant and life.