Mitsubishi Electric MELSERVO-J5 MR-J5-G Series, User Manual

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5 CHARACTERISTICS
5.2 Power supply capacity and generated loss
129
5
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 15 °C at an ambient temperature of 40 °C. Calculate the necessary heat dissipation area
of the cabinet with the equation below (10.1) while allowing a margin of approximately 5 °C for a maximum ambient
temperature of 60 °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 (10.1), 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 128 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. The following page contains
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 128 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.
Using servo amplifier with DC power supply input
The power supply capacity is the same as that for the AC power supply input.

Page 122 Power supply capacity and generated loss
K • Δ T
P
A = ∙ ∙ ∙ (10.1)
(Outside the
cabinet)
(Inside the cabinet)
Air flow