Siemens SIMOTICS SD Operating Instructions Manual page 40

Electrical connection
6.1 Connecting the machine
The technical specifications stipulate the following that have to be taken into account with
respect to the motor connection:
● Direction of rotation.
● The number and arrangement of the terminal boxes.
● The circuit and connection of the machine winding.
The following features make this type of electrical connection different from that for standard
machines:
● Maintain the area A in EN / IEC 60034-1 (VDE 0530-1) (±5 % voltage or ±2 % frequency
deviation, waveform, line supply symmetry) so that the temperature rise remains within
the permissible limits.
● Larger deviations from the rated data may result in electrical machines heating up to
impermissible levels. This information must be specified on the rating plate. Under no
circumstances exceed the limits!
● Protect every machine with type of protection increased safety "e" in accordance with
EN / IEC 60079-14 against an inadmissible temperature rise using a current-dependent,
delayed circuit breaker with phase failure protection and asymmetry detection
corresponding to EN / IEC 60947 or using an equivalent device in all phases.
● For machines with type of protection increased safety "e", select the overcurrent device
with current-dependent delayed trip so that the tripping time, which should be taken from
the characteristic of the switch for the ratio I
longer than the safe-locked rotor time t
rotor time t
certified tripping unit in accordance with RL 94/9/EC.
● For machines with increased safety "e" type of protection, in the event of a locked rotor
the protective device must disconnect within the t
temperature class. Protect electrical machines for heavy duty starting (acceleration time >
1.7 x t
a starting monitoring function.
Direct monitoring of the winding temperature is permissible as a means of thermal
machine protection, provided that this is certified and specified on the rating plate.
● With pole-changing machines, separate, interlocked protective devices are required for
each speed step. Devices with an EC-type examination certificate are recommended.
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from the rating plate. Set the protective device to the rated current. Use a
E
time) according to the specifications of the EC-type examination certificate using
E
/ I of the machine to be protected, is no
A N
. Take the ratio I / I
E A N
time specified for the relevant
E
Operating Instructions, 05/2014, 5 610 00000 02 000
as well as the safe-locked
Low-voltage motors