Product Reference - Oriental Motor

Technical Reference
●Changes in Air Flow – Static Pressure Characteristics Using Two Fans
By using two fans featuring the same characteristics together, you can change the characteristics of the fans.
Fig. 8 When Using Two Fans
Static Pressure [inH2O]
0.6
0.5
0.4
0.3
0.2
0.1
0
Static Pressure [Pa]
140
120
100
80
60
40
20
One Fan
One Fan
Two Fans
Two Fans
0
0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
Air Flow [m 3 /min]
0 50 100 150 200 250
Air Flow [CFM]
MU1238A-21B
50 Hz, 115 VAC
2800
2400
2000
1600
1200
800
400
0
Speed [r/min]
Fig. 9 Changes in Air Flow – Static Pressure Characteristics Using Two Fans
Static Pressure [inH2O]
0.6
0.5
0.4
0.3
0.2
0.1
0
Static Pressure [Pa]
160
140
120
100
80
60
40
20
One Fan
One Fan
Two Fans
MU1238A-21B
60 Hz, 115 VAC
Two Fans
0
0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
Air Flow [m 3 /min]
0 50 100 150 200 250
Air Flow [CFM]
3200
2800
2400
2000
1600
1200
800
400
0
Speed [r/min]
As shown in Fig. 9, the maximum air flow is approximately twice as large using two fans.
●Changes in the Air Flow – Static Pressure Characteristics with Installation of Accessories
When installing a fan in equipment, the safety and reliability of the overall apparatus
can be significantly improved by attaching accessories such as finger guards
0.35
and filters. However, these parts produce air flow resistance, affecting fan
80
0.30
characteristics and fan noise. This should be taken into account when selecting
70
fans and accessories.
The graph in Fig. 10 shows data regarding pressure loss caused by its
accessories for a frame size 119 mm (4.69 in.) sq. fan. The filter causes the most
significant pressure loss, while the finger guard causes little loss.
Static Pressure [inH2O]
0.25
0.20
0.15
0.10
0.05
For frame size 119 mm (4.69 in.) sq. Fans
Static Pressure [Pa]
60
50
40
30
20
10
Filter
Screen
Finger Guard
0
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Air Flow [m 3 /min]
0 20 40 60 80 100 120
Air Flow [CFM]
Fig. 10 Pressure Loss Caused by Accessories
The graphs in Fig. 11 show how characteristics may change with installation of accessories, using the MU1225S-21 as an example.
70
50 Hz, 115 VAC
70
60 Hz, 115 VAC
0.25
60
0.25
60
Static Pressure [inH2O]
0.20
0.15
0.10
0.05
Static Pressure [Pa]
50
40
30
20
10
No Accessories
Finger Guard Equipped
Screen Equipped
Filter Equipped
Static Pressure [inH2O]
0.20
0.15
0.10
0.05
Static Pressure [Pa]
50
40
30
20
10
No Accessories
Finger Guard Equipped
Screen Equipped
Filter Equipped
0
0
0 0
0 0.4 0.8 1.2 1.6 2.0
0 0.4 0.8 1.2 1.6 2.0
Air Flow [m 3 /min]
Air Flow [m 3 /min]
0 10 20 30 40 50 60 70
0 10 20 30 40 50 60 70
Air Flow [CFM]
Air Flow [CFM]
Fig. 11 Changes in Characteristics with Accessories Equipped to the MU1225S-21
As the Fig. 11 shows, the greater the pressure loss caused by accessories, the greater the reduction in air flow – static pressure characteristics.
F-70 ORIENTAL MOTOR GENERAL CATALOG 2009/2010