Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 253

10. CHARACTERISTICS
10.2 Power supply capacity and generated loss
(1) Amount of heat generated by the servo amplifier
Table 10.1 indicates servo amplifiers' power supply capacities and losses generated under rated load. For
thermal design of an enclosure, use the values in Table 10.1 in consideration for the worst operating
conditions. The actual amount of generated heat will be intermediate between values at rated torque and
servo off according to the duty used during operation. When the servo motor is operated at less than the
maximum speed, the power supply capacity will be smaller than the value in the table, but the servo
amplifier's generated heat will not change.
Table 10.1 Power supply capacity and generated heat per servo amplifier at rated output
Servo amplifier
HF-KN053 13
HF-KP053G1/G5/G7
MR-JN-10A (1) HF-KP13G1/G5/G7
HG-KR053G1/G5/G7
HG-KR13G1/G5/G7
HF-KN23
MR-JN-20A (1) HF-KP23G1/G5/G7
HG-KR23G1/G5/G7
HF-KN43
MR-JN-40A
HF-KP43G1/G5/G7
HG-KR43G1/G5/G7
Note 1. Note that the power supply capacity will vary according to the power supply impedance. This value is applicable when the power
factor improving reactor is not used.
2. Heat generated during regeneration is not included in the servo amplifier-generated heat. To calculate heat generated by the
regenerative option, refer to section 11.2.
(2) Heat dissipation area for enclosed servo amplifier
The enclosed control box (hereafter called the control box) which will contain the servo amplifier should be
designed to ensure that its temperature rise is within 10
(41 ) safety margin, the system should operate within a maximum 55
enclosure heat dissipation area can be calculated by Equation 10.1.
P
A = T ............................................................................................................................................ (10.1)
K
A : Heat dissipation area [m
P : Loss generated in the control box [W]
T : Difference between internal and ambient temperatures [ ]
K : Heat dissipation coefficient [5 to 6]
When calculating the heat dissipation area with Equation 10.1, assume that P is the sum of all losses
generated in the enclosure. Refer to Table 10.1 for heat generated by the servo amplifier. "A" indicates the
effective area for heat dissipation, but if the enclosure is directly installed on an insulated wall, that extra
amount must be added to the enclosure's surface area. The required heat dissipation area will vary wit the
conditions in the enclosure. Therefore, arrangement of the equipment in the enclosure and the use of a
cooling fan should be considered. Table 10.1 lists the enclosure dissipation area for each servo amplifier
when the servo amplifier is operated at the ambient temperature of 40
(Note 1)
Servo motor Power supply
capacity[kVA]
2 ]
Servo amplifier-generated heat[W]
At rated torque
0.3 20
0.5 20
0.9 30
at the ambient temperature of 40 . (With a 5
10 - 2
(Note 2)
With servo off
10
10
10
(131 ) limit.) The necessary
(104 ) under rated load.
Area required for
heat dissipation
[m ]
2
0.5
0.5
0.5