Panasonic M41A1G4L Operating Instructions Manual

Contents

– A-38 –Panasonic Corporation Electromechanical Control Business Divisionindustrial.panasonic.com/ac/e/ © Panasonic Corporation 2018 AQCTB02E 201806-E – A-39 –Panasonic Corporation Electromechanical Control Business Divisionindustrial.panasonic.com/ac/e/ © Panasonic Corporation 2018 AQCTB02E 201806-EHandling instructionsImpedance protectImpedance protect is a means to prevent burning of a motor if it becomes failure i.e. in lock state, even if it is notprovided with a safety device such as thermal protector. This is because the amount of current will not increaseduring locking state. It is blocked by the impedance produced by thin wire coil. Without this impedance protect,the motor temperature rises to 75 K (deg) or more during locking state and winding coil may be burned.Panasonic geared motors of 4-pole, 6 W or smaller are provided with the impedance protect and conform to ULstandard UL2111.The impedance protect should be activated only when its burning protection feature is absolutely necessary. Thisimplies that the motor must be used under the maximum permissible temperature. The expected motor lifedecreases by the factor if 1/2, 1/4 and so on as the temperature increases in step of 8 ˚C beyond the maximumpermissible temperature.* UL standard specifies the impedance protect value to 125 K (deg) at winding for Japanese version and 135 K(deg) for international version.Thermal protectorThe thermal protector is a safety device which automatically turns off the motor current as the motor windingtemperature exceeds the preset temperature and turns on the current again as the temperature drops below thepreset temperature.• Fig. 3 Operation of thermal protectorFigure 3 illustrates on/off cycle of the thermal protector. On Panasonic motors, threshold temperature is set asshown below.Motors conforming to international standards1 (open) 130 ˚C ± 5 ˚C2 (closed) 90 ˚C ± 15 ˚CJapanese version, variable speed 90 W motors1 (open) 120 ˚C ± 5 ˚C2 (closed) 77 ˚C ± 15 ˚CThese settings and time t1 and t2 vary depending on operating environment and loads.For compact geared motor with thermal protector, refer to the separate Panasonic international motor catalog.Figure 2 shows the limit curve for continuous intermittent running for the reversible motors. Horizontal axis showsthe running time t1 and vertical axis shows the pause time t2. The motor can be operated for a continuousintermittent running in the range of these lines.In this figure, each line represents as below:(1) Motor alone running at 60 Hz(2) Motor alone running at 50 Hz(3) Motor with gear head running at 60 Hz(4) Motor with gear head running at 50 HzFor example, if you want to make continuous intermittent running of the motor alone with a cycle of t1 = 20 minand t2 = 2 min, the line under the crossing point of t1 = 20 and t2 = 2 is line (4). Hence, you can only make acontinuous intermittent running with motor with gear head at 50 Hz under these conditions. If you want to run themotor alone and at 60 Hz for 20 minutes, you need to have the following pause time.(1) 10.1 minutes for the motor alone at 60 Hz(2) 4.6 minutes for the motor alone at 50 Hz(3) 3.8 minutes for the motor with gear head at 60 HzIf you fix the pause time to 2 minutes and want to see how long you can run the motor continuously, find thecrossing point of t1 and each line while t2 = 2 (constant), and each value becomes as below.(1) 2.5 minutes of running time for the motor alone at 60 Hz(2) 7 minutes of running time for the motor alone at 50 Hz(3) 10 minutes of running time for the motor with gear head at 60 Hz(4) 27.5 minutes of running time for the motor with gear head at 50 HzTemperature (˚C)21t2 t1Time (min)Pause RunningTemperature rise of reversible motorReversible motor is 30-minute rating when it is running alone. However, when it is used with the gear head,continuous running time will be extended thanks to heat radiation effect of the gear head. The table below showswhich motor can operate continuously under such condition. When these motors are operated intermittently, thetemperature rise will be saturated at certain value depending on the cycle of intermittent running.(2)(1) (3)(4)1 min10 min30 secPause time t2 (min)10 20 30 40 50 60Running time t1 (min)70• Fig. 2 Usable range of reversible motor (intermittent)• Continuous running of reversible motorSize60 mm sq.(2.36 inch sq.)70 mm sq.(2.76 inch sq.)80 mm sq.(3.15 inch sq.)90 mm sq.(3.54 inch sq.)Motor model No.M6RX4G4LM6RX6G4LM7RX10G4LM7RX15G4LM8RX20G4LM8RX25G4LM9RX40G4LM9RX60G4LM9RX90G4LContinuous runningwith gear head50 Hz 60 Hz* : Continuous running is possible : Continuous running is not possibleTemperature rise of motor