ABB PVS800-57-0100kW-A - Calculating the Required Static Pressure Difference

70 Mechanical installation
Calculating the required static pressure difference
The required static pressure difference between the exit air duct and the inverter
installation room can be calculated as follows:
where
p
d
dynamic pressure
air density (kg/m
3
)
v
m
average air velocity in the exit duct(s) (m/s)
q rated air flow of the inverter (m
3
/s)
A
c
cross-sectional area of the exit duct(s) (m
2
)
Example:
The cabinet has 3 exit openings of 315 mm diameter. The rated air flow of the cabinet is
3760 m
3
/h = 1.0 m
3
/s.
A
c
= 3 • 0.315
2
• / 4 = 0.234 m
2
v
m
= q / A
c
= 1.0 / 0.234 = 4.3 m/s
p
d
= 0.5 • • v
m
2
= 0.5 • 1.1 • 4.3
2
= 10 Pa
The required pressure in the exit air duct is then, 1.5…2 • 10 Pa = 15…20 Pa, below the
pressure in the room.
More information: Contact ABB.
p
s
= (1.5…2) • p
d
ǻ
p
d
= 0.5 •

• v
m
2
v
m
= q / A
c


