SIEMENS
2/43
Siemens D 83.1 · 2016
2
Motors with Explosion Protection
LOHER CHEMSTAR and VARIO 1PS4 and 1PS5 motor series
General information
■
Technical specifications
(continued)
Electrical design
The insulation system of the 1PS4 and 1PS5 motor series is
suitable for line voltages up to 690 V. The connection system
(terminal box, terminals) is also designed for this rated voltage.
The explosion-proof motors are equipped with 6 terminals. They
can thus be operated in star or delta. If a voltage variant with
dual voltage e.g. 400 V
/690 VY is selected, the rated data of
both voltage levels will be stamped on the rating plate.
The motors in the 1PS4 and 1PS5 series are manufactured with
an insulation system in thermal class 155 °C. Utilization at rated
operation corresponds to thermal class 130 °C.
Operation on a frequency converter
The general use of high-quality insulation systems enable
operation on a frequency converter.
The permissible speed and torque range is stamped on an
additional rating plate.
For operation on a frequency converter, the motor with explosion
protection must be fitted with PTC thermistors (or Pt100 as an
option for LOHER VARIO). These are installed in the stator
winding and, in combination with a certified trip unit (EU type
examination certificate), they perform sole motor protection in
the case of converter operation. Motor circuit breakers can be
dispensed with.
Line operation
Motors operated directly on the line must be protected, e.g. by a
suitable motor circuit breaker. Alternatively, motor protection using
a PTC thermistor for full motor protection (sole protection) may be
selected on request. As the load case "blocked shaft, motor draws
full starting current" also has to be monitored, this version cannot
be used consistently.
The larger the motor and the smaller the number of poles, the
more difficult it is to achieve sole protection using PTC thermistors
in line operation. Due to the laws of increasing size, larger
machines become ever more "rotor-critical". The sole protection
limit for 4-pole motors typically lies in the region of frame size 280.
Voltage tolerances
The motors are suitable for operation with voltage and frequency
tolerances according to EN 60034-1.
In addition, tests are to be performed to ensure that the
permissible temperature limits for the outer surface of the
explosion-proof enclosure according to EN 60079-1 are not
exceeded during continuous operations at the voltage limits
(± 10%).
The motors in the 1PS4 and 1PS5 series in this catalog are
certified for T4. The maximum permitted surface temperature is
135 °C.
Three-phase motors with external cables
Three-phase motors with externally routed connecting cables are
used in machines or ventilation systems in which the electrical
connections are routed via a separately mounted terminal box due
to the space constraints.
Design
The motors correspond to the surface-cooled versions in this
catalog. A gland plate is mounted in place of the terminal box
(Options
W38/W39
).
Explosion protection:
II 2G Ex d IIC T4 Gb
Frame sizes and types of construction:
see dimensional
drawings
Coolant temperature
:
-20 to +50 °C
Connection cable
(standard design): NSSHöu-J
The free length of connection cable must be specified when
ordering. The standard length is 1.5 m. Two or more cable
entries are used in the case of pole-changing or single-speed
motors with rated current > 70 A.
Rated voltage:
1000 V
Max. operating temperature at conductor:
-20 to +80 °C
G_D083_XX_00073
© Siemens AG 2016