A-17
■
Calorific values of inverters and amount of air to be ventilated
The VF-A7 series of inverter loses about 5% of energy when switching electric currents from AC,
DC, then to AC. To limit a temperature rise due to this energy loss, it is necessary to forcefully
ventilate and cool down the cabinet in which the inverter is installed.
The table below lists the amounts of air to be ventilated forcefully and the heat radiation areas
required for closed-type cabinets containing an inverter.
Voltage
class
Applicable
motor
(kW)
Calorific value
of inverter
(W)
Amount of air to be
ventilated forcefully
(m
3
/min.)
Heat radiation area required
for closed-type
cabinet
(m
2
)
0.4
50
0.29
1.0
0.75
70
0.40
1.4
1.5
110
0.63
2.2
2.2
140
0.80
2.8
3.7
220
1.3
4.4
5.5
310
1.8
6.2
7.5
420
2.4
8.4
11
580
3.3
11.6
15
770
4.4
15.4
18.5
940
5.4
18.8
22
1110
6.3
22.2
30
1490
8.5
29.8
37
1530
8.7
30.6
45
1850
10.5
37.0
55
2250
12.8
45.0
75
3050
17.4
61.0
200V
90
3650
20.8
73.0
0.75
70
0.40
1.4
1.5
110
0.63
2.2
2.2
140
0.80
2.8
3.7
220
1.3
4.4
5.5
280
1.6
5.6
7.5
370
2.1
7.4
11
530
3.0
10.6
15
710
4.0
14.2
18.5
800
4.6
16.0
22
940
5.4
18.8
30
1270
7.2
25.4
37
1270
7.2
25.4
45
1490
8.5
29.8
55
1810
10.3
36.2
75
2300
13.1
46.0
90
2750
15.7
55.0
110
3350
19.1
67.0
132
4010
22.9
80.2
160
4850
27.6
97.0
220
6650
37.9
133.0
400V
280
8450
48.2
169.0
Note)The calorific values in the above table do not include those of optional external devices
(such as input reactors, DC reactors and radio noise filters).
