5.
Hazardous area motors
in variable speed
operation
5.1 Introduction
This part of the manual provides additional instructions
for motors used in hazardous areas in frequency
converter supply.
Additional information may be required by ABB to
decide on the suitability for some machine types used in
special applications or with special design modifi ca-
tions.
5.2 Main requirements
according to EN and IEC
standards
Flameproof motors Ex d, Ex de
According to the standards, the motor must be dimen-
sioned so that the maximum outer surface temperature
of the motor is limited according to the temperature
class (T4, T5, etc.). In most cases this requires either
type tests or control of the outer surface temperature of
the motor.
Most ABB fl ameproof motors for temperature class T4
have been type tested with ABB ACS800 converters
utilizing Direct Torque Control (DTC), and these combi-
nations can be selected using the dimensioning instruc-
tions provided in Chapter 5.8.2.
In case of other voltage source converters (not DTC-
controlled as ACS800) with pulse width modulation type
of control (PWM), combined tests are usually needed to
confi rm the correct thermal performance of the motor.
These tests can be avoided if fl ameproof motors are
equipped with thermal sensors intended for control of
surface temperatures. Such motors have the following
additional markings on the rating plate: - "PTC" with the
tripping temperature and "DIN 44081/82".
In the case of voltage source PWM converters with a
minimum switching frequency of 3 kHz or higher,
instructions provided in Chapter 5.8.3 must be used for
preliminary dimensioning.
For more information on T5 and T6 temperature class
fl ameproof motors used with variable speed drives,
please contact ABB.
Increased safety motors Ex e
ABB does not recommend the use of random wound
low voltage increased safety motors with variable speed
drives. This manual does not cover these motors in
variable speed drives.
Non-sparking motors Ex nA
According to the standards, the combination of motor
and converter must be tested as a unit or dimensioned
by calculation.
EN – 12
ABB non-sparking cast iron motors have been type
tested with ABB ACS800 converters utilizing DTC
control, and these combinations can be selected using
the dimensioning instructions provided in Chapter 5.8.2.
In the case of voltage source PWM converters with a
minimum switching frequency of 3 kHz or higher,
preliminary dimensioning instructions provided in
Chapter 5.8.3 in this manual can be used. The fi nal
values must be verifi ed by combined tests.
Dust ignition proof motors DIP, Ex tD
According to the standards, the motor must be dimen-
sioned so that the maximum outer surface temperature
of the motor is limited according to the temperature
class (e.g. T125°C). For more information on a tem-
perature class lower than 125°C, please contact ABB.
ABB DIP/Ex tD motors (125°C) have been type tested
with ACS800 converters utilizing DTC control, and
these combinations can be selected using the dimen-
sioning instructions provided in Chapter 5.8.2.
In the case of any other voltage source converter with
pulse width modulation type of control (PWM), com-
bined tests are usually needed to confi rm the correct
thermal performance of the motor. These tests can be
avoided if DIP-motors are equipped with thermal sen-
sors intended for control of the surface temperatures.
Such motors have the following additional markings on
the rating plate: - "PTC" with the tripping temperature
and "DIN 44081/82".
In the case of voltage source PWM converters with a
minimum switching frequency of 3 kHz or higher,
instructions provided in Chapter 5.8.3 can be used for
preliminary dimensioning.
5.3 Winding insulation
5.3.1 Phase to phase voltages
The maximum allowed phase to phase voltage peaks in
the motor terminal as a function of the rise time of the
pulse can be seen in Figure 4.
The highest curve "ABB Special Insulation" applies to
motors with a special winding insulation for frequency
converter supply, variant code 405.
The "ABB Standard Insulation" applies to all other
motors covered by this manual.
5.3.2 Phase to ground voltages
The allowed phase to ground voltage peaks at motor
terminals are:
Standard Insulation 1300 V peak
Special Insulation 1800 V peak
ABB/Low Voltage Motors/ Ex manual 01-2007