SIEMENS
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Siemens MD 50.8 · 2017
Configuring guide
Configuring a three-phase motor
2
■
Degrees of protection
The motors are supplied in IP55 to standard IEC 60034-5. They
can be installed in dusty or humid environments. The motors are
suitable for operation in tropical climates. Guide value below
60 % relative air humidity for a coolant temperature of +40 °C.
Other requirements on request.
The first digit of the degree of protection indicates the degree to
which an enclosure provides protection against contact and the
ingress of foreign bodies.
The second digit indicates the protection that an enclosure
offers regarding the ingress of water.
Increased corrosion protection as well as additional protective
measures for the winding (protection against moisture and acid,
corrosion protection in the motor) can support the selected
degree of protection.
The degree of protection only refers to the motor. When selecting
higher degrees of protection, the equipping on the gearbox side
should be taken into account (seals, vents).
■
Cooling and ventilation
When the geared motor is mounted and the air intake is
restricted, you must ensure that a minimum clearance is main-
tained between the fan cover and the wall and that the cooling
air is not immediately drawn in again.
Further, it must be guaranteed that the cooling air flow to the
gearbox is not obstructed. As a consequence, the gearbox
operating temperature can be further reduced.
Forced ventilation
The use of a separately driven fan is recommended to increase
motor utilization at low speeds and to limit noise generation at
speeds significantly higher than the synchronous speed. Both
are mainly used in conjunction with inverter operation.
Typical areas of application for forced ventilation:
•
High number of starting operations
•
Inverter drives with a control range > 1:20
•
Inverter drives with rated torque at low speeds
•
Inverter drive with high motor speeds
•
Noise reduction
•
At high speeds
First
digit
Brief description
Second
digit
Brief description
4
The motor is
protected against
solid objects larger
than 1 mm.
4
The motor is protected
against water splashed
from all sides.
5
The motor is
protected against
dust.
5
The motor is protected
against strong jets of
water.
6
The machine is
dust-tight.
6
The motor is protected
against "heavy seas" or
powerful jets of water.
7
The motor is protected
against immersion.
8
The motor is protected
against long periods of
immersion under
pressure.
© Siemens AG 2017