Heat Dissipation Area For Enclosed Type Cabinet - Mitsubishi Electric -MR-CV User Manual

Heat dissipation area for enclosed type cabinet

For the heat dissipation area of the drive unit/servo amplifier, refer to the drive unit/servo amplifier user's manual and
instruction manual.
The enclosed type cabinet (hereafter called the cabinet) that stores the converter unit should be designed to ensure that its
internal temperature rise is within +10 °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 55 °C.
P
A = ∙ ∙ ∙ (10.1)
K • ΔT
A: Heat dissipation area [m
P: Loss generated in the cabinet [W]
ΔT: 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 converter unit.
Page 67 Amount of heat generated by converter unit
"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 converter unit cabinets when operating the converter unit at a
rated load in ambient temperatures of 40 °C.
Page 67 Amount of heat generated by converter unit
(Outside the
cabinet)
(Inside the cabinet)
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.
6 CHARACTERISTICS
68
6.2 Power supply capacity and generated loss
2
]
Air flow