50
5 CHARACTERISTICS
5.2 Power supply capacity and generated loss
Generated loss
Servo amplifier generated heat
The following table indicates the losses generated by servo amplifiers under rated load. For thermal design of an enclosed
type cabinet, use the values in the tables in consideration for the worst operating conditions including environments and
operation patterns. The actual amount of generated heat depends on the frequency of operation and will be between the "At
rated output" and "At servo-off" values.
*1 The values stated for heat generated by the servo amplifier do not take into account the heat generated during regeneration. To
calculate heat generated by the regenerative option, refer to the following.
Heat dissipation area for enclosed type cabinet
The enclosed type cabinet (hereafter called the cabinet) that stores the servo amplifier should be designed to ensure that its
internal temperature rise is 10 °C at an ambient temperature of 40 °C. Calculate the necessary heat dissipation area
of the cabinet with the equation below (5.1) while allowing a margin of approximately 5 °C for a maximum ambient
temperature of 55 °C.
A: Heat dissipation area [m
2
]
P: Loss generated in the cabinet [W]
T: Difference between internal and ambient temperatures [°C]
K: Heat dissipation coefficient [5 to 6]
When calculating the heat dissipation area with the equation (5.1), assume that P is the sum of all losses generated in the
cabinet. Refer to the following for details about the heat generated by the servo amplifier.
Page 50 Servo amplifier generated heat
"A" indicates the effective area for heat dissipation, but if the cabinet is directly installed on an insulated wall, that extra
amount must be added to the cabinet's surface area. The required heat dissipation area will vary with the conditions in the
cabinet. If convection in the cabinet is poor and heat builds up, effective heat dissipation will not be possible. Therefore,
arrangement of the equipment in the cabinet and the use of a cooling fan should be considered. Refer to the following section
for information on the required heat dissipation area (estimated) of servo amplifier cabinets when operating amplifiers at a
rated load in ambient temperatures of 40 °C.
Page 50 Servo amplifier generated heat
When air flows along the outer wall of the cabinet, effective heat exchange is possible, because the temperature slope inside
and outside the cabinet is steeper.
Servo amplifier
Servo amplifier-generated heat [W]
Area required for heat
dissipation [m
2
]
At rated output
At servo-off
MR-JET-10_
25
15
0.5
MR-JET-20_
30
15
0.6
MR-JET-40_
35
15
0.7
MR-JET-70_
60
15
1.0
MR-JET-100_
60
15
1.0
MR-JET-200_
120
20
2.4
MR-JET-300_
120
20
2.4
K •
Δ
T
P
A =
∙
∙
∙
(5.1)
(Outside the
cabinet)
(Inside the cabinet)
Air flow
Summary of Contents for Melservo-Jet MR-JET G-N1 Series
Page 1: ...MR JET User s Manual Hardware MR JET _G MR JET _G N1 Mitsubishi Electric AC Servo System ...
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