
2-2
When employing external cooling
In external cooling, the heat sink, which dissipates about 70% of the total heat (total
loss) generated into air, is situated outside the equipment or the panel. The external
cooling, therefore, significantly reduces heat radiating inside the equipment or panel.
To employ external cooling for inverters (except DCR built-in type) of 40 HP or below,
use the mounting adapter for external cooling (option); for those of 50 HP or above,
simply change the positions of the mounting bases.
The DCR built-in type of 40 HP or below cannot employ external cooling.
Prevent lint, paper fibers, sawdust, dust, metallic chips, or other foreign
materials from getting into the inverter or from accumulating on the heat sink.
Otherwise, a fire or accident could occur.
Figure 2.2 External Cooling
To utilize external cooling for inverters of 50 HP or above, change the positions of the top and bottom mounting bases
from the edge to the center of the inverter as shown in Figure 2.3.
Screws differ in size and count for each inverter. Refer to the table below.
Table 2.4 Screw Size, Count and Tightening Torque
Inverter type
Base fixing screw
(Screw size and q'ty)
Case fixing screw
(Screw size and q'ty)
Tightening
torque
lb-in (N
m)
EQ7-2050-C /EQ7-2060-C
EQ7-4050-C
EQ7-4100-C
M6
20
5 pcs for upper side,
3 pcs for lower side
M6
20
2 pcs for upper side
51.3
(5.8)
EQ7-2075-C / EQ7-4100-C
EQ7-4125-C
M6
20
3 pcs each for upper and lower
sides
M6
12
3 pcs for upper side
51.3
(5.8)
EQ7-2125-C
EQ7-4150-C / EQ7-4200-C
M5
12
7 pcs each for upper and lower
sides
M5
12
7 pcs for upper side
31.0
(3.5)
EQ7-4250-C / EQ7-4300-C
M5
16
7 pcs each for upper and lower
sides
M5
16
7 pcs for upper side
31.0
(3.5)
EQ7-2150-C
EQ7-4350-C / EQ7-4450-C
M5
16
8 pcs each for upper and lower
sides
M5
16
8 pcs for upper side
31.0
(3.5)
EQ7-4500-C / EQ7-4600-C
EQ7-4700-C / EQ7-4800-C
M5
16
2 pcs each for upper and lower
sides
M6
20
6 pcs each for upper and lower
sides
M5
16
2 pcs each for upper and lower
sides
M6
20
6 pcs each for upper and lower
sides
31.0
(3.5)
51.3
(5.8)
EQ7-4900-C / EQ7-41000-C
M8
20
8 pcs each for upper and lower
sides
M8
20
8 pcs each for upper and lower
sides
119
(13.5)
1) Remove all base fixing screws and case fixing screws from the top of the inverter.
2) Move the top mounting base to the center of the inverter and secure it to the case fixing screw holes with the base
fixing screws. (After changing the position of the top mounting base, some screws may be left unused.)
3) Remove the base fixing screws from the bottom of the inverter, move the bottom mounting base to the center of the
inverter, and secure it with the base fixing screws, just as in step 2). (Inverters of 450 HP or below have no case
fixing screws on the bottom.)