Electric motors Size 63 - 225 ATEX / IECEx
Construction and function
26
2021-05-31
4.5 Operation on the frequency converter
The motors of EX versions “pressure-proof encapsulation” Ex d(e) and “protection by housing” Ex t are
approved for inverter operation. For approved versions, the possible frequency range must be obtained from
the EU prototype test certificate.
The chart and the table below show and explain the most common curves for FI operation. The permissible
torque at 50 Hz depends on the size, the number of poles and the performance; refer to the HEW catalogue
“Explosion protected electric motors” (Part 20).
Permissible torque curve
Frequency (Hz)
Characteristic
curve
Frequency
Motor
version
Motor
voltage /
circuit
Inverter
Ventilation
Torque curve
in frequency range
acc. to Catalogue Part 20
1
5 - 50 Hz
230/400 V
400 V Y
U/f=constant
internal fan
reduced
400/690V
400 V
U/f=constant
2
5 - 50 Hz
230/400 V
400 V Y
U/f=constant
external
ventilation
constant
400/690V
400V
U/f=constant
3
50 - 87Hz
230/400 V
400 V Y
U=constant
internal fan
drops with 1/f
400/690V
400V
U=constant
Field weakening operation
4
50 - 87Hz
230/400 V
230V
U/f=constant
internal fan
constant
87 Hz curve
When the frequency range is specified in the order,
the motors come with an additional plate indicating the
FI operation data given on the right:
(Example: DCEx 112 M/4 K
– 400 V
50 Hz 4.0 kW)
DCEx 112 M/4 K / Motor number
40 V 5 Hz 0.24 kW Tperm.= 16 Nm
400 V 50 Hz 4.0 kW Tperm.= 27 Nm
400 V 87 Hz 4.0 kW Tperm.= 16 Nm
Sections 4.3 and 4.4 describe the motor protection for frequency inverter operation.
Use shielded cables to prevent electromagnetic interference.
We recommend using insulated bearings for motors of size 250 and greater.
Further information can be requested from the HEW headquarters in Herford at any time.
Pos : 5. 1 / KN2006- SM/ nL.... ... ... Seit enumbr uc h . ... ... ... @ 8\ mod_1141998334703_0. doc @ 75489
