LENZE
Duty cycle S2
Operating mode S3
Operating mode S6
Operating time
P
perm
Operating time
P
perm
Operating time
P
perm
[min]
P
r
[%]
P
r
[%]
P
r
10
1.4 … 1.5
15
1.4 … 1.5
15
1.5 … 1.6
30
1.15 … 1.2
25
1.3 … 1.4
25
1.4 … 1.5
60
1.07 … 1.1
40
1.15 … 1.2
40
1.3 … 1.4
90
1.0 … 1.05
60
1.05 … 1.1
60
1.15 … 1.2
1
General information
Overview Motor drive dimensioning
1-9
Small drives en 07/2010
Operating modes
The ratings are obtained when the following conditions are
fulfilled:
˘
Ambient temperature up to 40 °C
˘
Installation at a height up to 1000 m a.m.s.l.
˘
Unobstructed airflow
˘
No recycling of the warm exhaust air via the intake
The operating mode is important when choosing a motor.
A motor heats up much less, for example, when loaded only
intermittently than when constantly under load, thus allo-
wing the selection of a smaller motor. In accordance with
VDE 0530, there are eight different modes of operation;
S1 to S8.
For
Continuous operation S1
the operating time at the
rated power is so long that the steady-state temperature of
the machine is reached. Such motors are suitable for conti-
nuous duty, i.e. they can be permanently loaded with the
rated load.
For
Short-time operation S2
the operating time is so short
in comparison to the resting time which follows it that the
steady-state temperature of the machine is never achieved.
In the resting time following the operating time the motor
cools down to the initial temperature.
With
Intermittent operation S3, S4, S5
the operation con-
sists of a repeating set of short-term duties. The running
time is normally 10 minutes. The resting periods between
the operating periods are sufficiently long for the machine
to cool down.
S3 operation occurs, when the heating effect of the starting
current is negligible, S4 when the effect of the starting cur-
rent cannot be disregarded, S5 when the braking current
causes additional heating of the machine.
With
continuous duty with intermittent loading S6
the
motor can cool down in the idle phases.
With
continuous operation with start-up and
braking S7
there are practically no pauses.
The machine is permanently under voltage.
Varying ambient conditions
Variations in the ambient conditions require a power reduc-
tion according to the factors given in Tables 2
and 3. The permissible continuous power is given by:
P
red
=
P
´
· P
N
P
N
Increased power in operating modes S2, S3 and S6
Effect of the ambient operating temperature
How the ambient operating temperature T
amb
affects
rated power
T
amb
[°C]
≤ 40
45
50
55
60
P
´
1
0.95
0.90
0.83
0.7
P
N