Handling Instructions - Panasonic M41A1G4L Operating Instructions Manual

Handling instructions

Temperature rise of motor
Temperature rise of reversible motor
Reversible 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 shows
which motor can operate continuously under such condition. When these motors are operated intermittently, the
temperature rise will be saturated at certain value depending on the cycle of intermittent running.
• Continuous running of reversible motor
Continuous running
with gear head
Size Motor model No.
50 Hz 60 Hz
M6RX4G4L
60 mm sq.
(2.36 inch sq.)
M6RX6G4L
M7RX10G4L
70 mm sq.
(2.76 inch sq.)
M7RX15G4L
M8RX20G4L
80 mm sq.
(3.15 inch sq.)
M8RX25G4L
M9RX40G4L
90 mm sq.
M9RX60G4L
(3.54 inch sq.)
M9RX90G4L
*
: Continuous running is possible : Continuous running is not possible
Figure 2 shows the limit curve for continuous intermittent running for the reversible motors. Horizontal axis shows
the running time t1 and vertical axis shows the pause time t2. The motor can be operated for a continuous
intermittent 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 Hz
For example, if you want to make continuous intermittent running of the motor alone with a cycle of t1 = 20 min
and t2 = 2 min, the line under the crossing point of t1 = 20 and t2 = 2 is line (4). Hence, you can only make a
continuous intermittent running with motor with gear head at 50 Hz under these conditions. If you want to run the
motor 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 Hz
If you fix the pause time to 2 minutes and want to see how long you can run the motor continuously, find the
crossing 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 Hz
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
• Fig. 2 Usable range of reversible motor (intermittent)
(2)
(1) (3)
(4)
10 min
1 min
30 sec
10 20 30 40 50 60 70
Running time t1 (min)
– A-38 –
© Panasonic Corporation 2018 AQCTB02E 201806-E
Impedance protect
Impedance protect is a means to prevent burning of a motor if it becomes failure i.e. in lock state, even if it is not
provided with a safety device such as thermal protector. This is because the amount of current will not increase
during 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 UL
standard UL2111.
The impedance protect should be activated only when its burning protection feature is absolutely necessary. This
implies that the motor must be used under the maximum permissible temperature. The expected motor life
decreases by the factor if 1/2, 1/4 and so on as the temperature increases in step of 8 ˚C beyond the maximum
permissible 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 protector
The thermal protector is a safety device which automatically turns off the motor current as the motor winding
temperature exceeds the preset temperature and turns on the current again as the temperature drops below the
preset temperature.
• Fig. 3 Operation of thermal protector
1
2
Pause Running
t2 t1
Time (min)
Figure 3 illustrates on/off cycle of the thermal protector. On Panasonic motors, threshold temperature is set as
shown below.
Motors conforming to international standards
1 (open) 130 ˚C ± 5 ˚C
2 (closed) 90 ˚C ± 15 ˚C
Japanese version, variable speed 90 W motors
1 (open) 120 ˚C ± 5 ˚C
2 (closed) 77 ˚C ± 15 ˚C
These 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.
Panasonic Corporation Electromechanical Control Business Division
industrial.panasonic.com/ac/e/
– A-39 –
© Panasonic Corporation 2018 AQCTB02E 201806-E