13
V20 Edition: 12 March
·
2019
Operating Manual DUM/F6-Servomotors
The evaluation of the temperature sensor belongs to the monitoring of the motor winding. The temperature
sensor follows rapid temperature changes only with delay. Especially the windings of small motors (DUM6-Ax)
are very sensitive to overload.
PTC thermistors are installed as standard in the DE winding head to protect the winding from thermal overload when the
temperature change is slow (temperature change in minutes or hours).
The maximum operating voltage of the PTC thermistors must not exceed 30V-.
Due to the non-ideal thermal coupling, the temperature sensor follows rapid winding temperature changes only with delay,
thus being unable to protect the winding if the thermal overload of the motor is transient and high. Therefore, additional
protection is required (such as monitoring I
2
xt by the converter electronic system) to protect the motor from fast-rising ther-
mal overload.
Monitoring the winding temperature
DUM6-A
with single PTC thermistor STM150E
DUM/F6-C; DUM/F6-D and DUM/F6-E
with triplex PTC thermistor STM150D
1 x 4000
1 x 1330
1 x 550
1 x 250
-20°C
130°C
145°C
150°C
155°C
165°C
W
id
e
r
s
ta
n
d
/
R
e
s
is
ta
n
c
e
[
Ω
]
Temperatur /
Temperature
3 x 4000
3 x 1330
3 x 550
3 x 250
-20°C
130°C
145°C
150°C
155°C
165°C
W
id
e
r
s
ta
n
d
/
R
e
s
is
ta
n
c
e
[
Ω
]
Temperatur /
Temperature
Note:
The built-in PTC thermistor is the basic version. Other temperature detectors such as KTY 84 or miniature thermal
time-delay switches are available as an option.
0
1
2
3
4
0
5
10
15
20
25
Zeit /
time
t [s]
I /
I
d0
DUM 6-Ax (betriebswarm / at operating temperature)
DUM 6-Ax (kalt / cold)
empfohlene Stromgrenze / recommended current limit
The characteristics apply in case of a failure. They must not be applied for normal motor operation.
The r.m.s. value of the motor current is not permitted to exceed the nominal continuous current I
dN
within any
cycle!
The maximum motor current must be limited to ensure that the temperature sensor trips quickly enough. (See the following
diagrams to adjust the recommended current limits.) If a higher current limit needs to be adjusted, the current must not
exceed the current-time values shown in the characteristics and the motor max. current I
max
.
