
6. HEAT GENERATION
B–65192EN/02
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6
HEAT GENERATION
(1) The heat generated by a servo amplifier unit can be calculated by the
following equations. In calculation, use appropriate values selected
from Tables 6.1 and 6.2 according to the models of the amplifier and
motor to be used.
Value determined depending on the motor for the second axis
Value determined depending on the motor for the first axis
Value determined depending on the unit
Total heat generation (W) = a + (c+d) + (c+d)
Heat generated in the cabinet (W) = b + (0.2c+d) + (0.2c+d)
(cooling by natural air flow)
Heat generated in the cabinet (W) = b + (0.1c+d) + (0.1c+d)
(cooling by forced air flow)
(Example) When the SVU2–20/40 is used to drive the
C12/2000 and C22/1500, the generated heat is calculated
as follows:
Each heat generationSVU2–20/40 a=29.8 b=29.8
αC12/2000 c=27.3 d=3.8
αC22/1500 c=53.0 d=8.6
Total heat generation=
29.8 + (27.3+3.8) + (53.0+8.6) = 122.5
Heat generated in the cabinet =
29.8 + (0.2 27.3+3.8) + (0.2 53.0+8.6) = 58.3
(cooling by natural air flow)
Heat generated in the cabinet =
29.8 + (0.1 27.3+3.8) + (0.1 53.0+8.6) = 50.2
(cooling by forced air flow)
(2) The amounts of generated heat listed above apply when all motors run
at the
respective continuous output ratings. These values may be
decreased during cabinet design, depending on the actual operating
condition.
(3) The servo amplifier heat sinks can be placed outside the cabinet
(except for some models). This configuration can reduce the heat
generated within the cabinet. The amount of heat generated in the
cabinet varies depending on whether the heat sink is cooled by natural
or forced air flow.