MOTOVARIO
Ventilation correction factor
Fv
Stagnant air (<0,5 m/s)
0.75
Indoor installation with slight ventilation
1
Indoor installation with good ventilation (>1,4 m/s)
1.4
Installazione all’aperto (>3,7 m/s)
1.9
Altitude correction factor (m)
Fa
0*
1
750
0,95
1500
0,9
2250
0,85
3000
0,81
2.4.2 Check
Application check
Except for continuous operating times below two (2) hours and successive pauses capable of bringing the
gear reducer back to ambient temperature, for each application it is advisable to verify the gear reducer’s
thermal limit according to the following formula:
Pm < Pth * Fc * Fv*Fa,
where:
Pm = input power to the gear reducer at 1400 rpm (4-pole motors)
Pth = thermal power at the reference conditions (see above table)
Fc = ambient and operating temperature correction factor
Fv = ventilation correction factor
Fa = altitude correction factor
The correction factors (Fc) refer to different operating conditions compared to the reference conditions, and
are provided by the following ISO14179 tables:
Fc
Duty per hour of operation %
100
80
70
40
20
Ambient
temperature °C
10
1,15
1,21
1,32
1,55
2,07
18
1,07
1,12
1,23
1,44
1,93
25
1,00
1,05
1,15
1,35
1,80
30
0,93
0,98
1,07
1,26
1,67
40
0,83
0,87
0,95
1,12
1,49
43
0,75
0,79
0,86
1,01
1,35
50
0,67
0,70
0,77
0,90
1,21
* Sea level
In case of operation at input speeds exceeding 2000 rpm, or ambient temperatures greater than 40°C, it is
advisable to contact out technical department.
S Series
/
ATEX
/
IEC
TECHNICAL CATALOGUE
2.4 THERMAL POWER
18