Bosch DOK-MOTOR-MCL Series, Project Planning Manual

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Cooling down
ϑ
e
Final over temperature or shutdown temperature in K
t Time in min
t
th
Thermal time constant in min (see motor data sheet)
Fig. 9-11: Cooling down of an electrical machine
9.10 Motor temperature monitoring
The motor temperature is monitored by two systems that are operated inde‐
pendently of each other
●
Temperature sensor (motor)
● Temperature model (controller)
and ensures thus the best protection of motors against irreversible damage
by thermal overload.
Primary parts of frame sizes MCP020 ... 070 are standardly fitted with an in‐
tegrated temperature sensor (KTY84-130) for measuring the winding temper‐
ature. An all-phase monitoring is impossible with only one KTY. Thus, it is
possible that a phase in standstill operation with continuous currents are near
the nominal current, which is monitored by a KTY, is thermally overloaded,
despite the KTY only displays measuring values < 110°C. The exclusive use
of the KTY for temperature monitoring means no sufficient motor protection
for the primary parts.
A possible form of an additional motor protection is, to limit the
motor current to 87% of the nominal current at low velocity (< 1
m/min) or at movement via a short traverse path (< 2 · t
P
).
The Rexroth IndraDrive control devices monitor the functionality of the tem‐
perature sensors. For further information, please refer to the functional de‐
scription of IndraDrive control devices.
Temperature sensor KTY84-130
KTY84-130 Value
Resistance at 25 °C min. 577 ... max. 629 Ohm
Resistance at 100 °C min. 970 ... max. 1000 Ohm
Continuous current at 100 °C 2 mA
Tab. 9-5: Standard values on temperature sensors KTY84-130
The response temperatures of the sensor are
⇒110 °C pre-warning temperature
⇒130 °C shut-off temperature
DOK-MOTOR*-MCL********-PR05-EN-P Bosch Rexroth AG 107/193
Rexroth IndraDyn L Ironless Linear Motors MCL
Application and construction instructions