Mechanical Installation (T1 to T9 Models)
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Table 4–2 Minimum effective area of the cabinet air inlet
"
on page 66
applies to
situations where only one AC drive is mounted in the cabinet. For a cabinet
containing multiple AC drives, calculate the total effective inlet area by summing each
single effective area according to the table. For example, if a cabinet contains eight
7.5 kW T3 models, two T5 models, and one T9 model, the minimum effective area of
the air inlet is 8 x 25 + 2 x 60 + 1 x 318 = 638 cm
2
.
If an air filter is installed at the air inlet, the air inlet resistance will rise significantly
and the ventilation opening area must be increased to 1.2–1.5 times the value
indicated in the table.
"
Table 4–2 Minimum effective area of the cabinet air inlet
"
on page 66
refers to the
actual through‑hole area in the cut‑out area. The effective area is calculated by
multiplying the cut‑out area by the cut‑out rate.
Design of top ventilation
Ensure smooth discharge of hot air from the cabinet to the outside to keep sufficient
heat dissipation for the AC drive. Use passive or active ventilation design for the
cabinet.
1. Passive ventilation (self‑ventilated)
In passive ventilation, hot air that flows upward is guided to the air outlet on the
top of the cabinet.
In passive ventilation,hot air may accumulate at the top of the cabinet, resulting in
increased air pressure at the top. At the same time, the air pressure at the cabinet
air inlet is low due to the suction of the AC drive fan. Therefore, there is an air
pressure difference between the inside, air outlet, and air inlet of the cabinet,
causing air flow. The hot air at the air outlet is forced to flow toward the air inlet
and then be taken into the AC drive again, causing a great temperature rise of the
AC drive and adversely affecting the performance of the AC drive.
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