nord 6051302, Operating And Assembly Instruction Manual

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Motors – Operating and Assembly Instructions
28 B 1091 en-2722
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3.1.5 Further operating conditions
The motors are designed for continuous operation and normal, non recurring starting, in which no
significant starting heat occurs.
Range A in EN 60034-1 (VDE 0530 Part 1) - Voltage ± 5%, Frequency ± 2%, curve form, mains
symmetry - must be complied with so that the development of heat remains within the permissible limits.
Any major deviations from the rated values can cause an impermissible increase in the development of
heat in the motor.
The motor temperature class stated on the type plate must at least conform to the temperature class of
any combustible gas that may occur.
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When operated on a frequency inverter, damaging bearing currents must be ruled out. This could be
caused by excessively high shaft voltages.
If the effective value of the shaft voltage (RMS) exceeds 250 mV, permissible technical measures must
be taken. If necessary, please contact the NORD service. Please also pay attention to the relevant PTB
data sheets. In addition to further information, details on the permissible frequency characteristic curves
can be found here.
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3.1.6 Protective devices
Each machine must be protected against impermissible heating during all phases by a current-
dependent and delayed circuit breaker with phase failure protection according to VDE 0660, functionally
tested by a notified body, or by an equivalent effective device. The protective device must be set to the
rated current. For windings with a delta circuit, the triggers are connected in series with the phase
windings and set to 0.58-x the rated current. If this circuit is not possible, additional protection measures
are required (e.g. thermal protection of the machine).
In case of a blocked rotor, the protective device must switch off within the
E
time specified for the
respective temperature class.
Electrical machines for heavy starting (acceleration time > 1,7 x t
E
time) must be protected by a start
monitoring device as specified in the EU type-examination certificate.
Thermal protection of the machine by means of direct temperature monitoring of the windings with a
PTC resistor temperature sensor is permitted, if this is certified and stated on the rating plate.
Do not apply voltages higher than 30 V to the PTC resistor temperature sensors!
For sole protection by PTC resistor temperature sensors, a functionally tested and certified PTC
triggering device of a notified body must be used. The PTC triggering device must have the following
protection class labelling:
II (2) G