low-voltage

■ Insulation, winding, motor protection, and anti-condensation heating
.
DURIGNIT ® Insulation IR 2000
■The DURIGNIT IR 2000 insulation
system comprises highgrade
enameled wires and insulating
sheet materials combined
with solvent-free impregnating
resin.
The system ensures a high level
of mechanical and electrical
strength as well as good serviceability
and a long motor life.
The insulation offers general
protection for the windings
against corrosive gases, vapors,
dust, oil and increased humidity,
and resists the normal
stresses of vibration.
The insulation is suitable for an
absolute humidity of up to 30 g
water per m3 . The windings
must not become moist. Higher
values on request!
■The windings of the 1LA8 motors
are impregnated using
the UV or VPI techniques.
Please inquire about extreme
applications.
All motors are designed for
class F.
Utilization of motors for rated
output and mains-fed operation
for class B.
All 1LA and 1LG motors can be
stamped with the ratings in accordance
with the selection tables
and rated voltage range as
well as with a service factor (SF)
of 1.1 (for 1LA9 and 1LG6 SF =
1.15) and 1.05 for frame sizes
400 and 450. Order Code C11.
The service factor is already
stamped on the rating plate of
standard ex-stock motors and
1LA8 motors.
If the motor is used for class F,
the rated output specified in the
selection and ordering data can
be increased by 10% (by 15%
for 1LA9 and 1LG6 and by 5%
for frame sizes 400 and 450).
Order Code C12.
If the catalogue ratings are
used, it is permissible to increase
the temperature of the
coolant to 55 °C (or to 50 °C for
frame sizes 400 and 450). Order
Code C13.
The service factor (SF) is not
stamped on the rating plate for
Order Codes C12 and C13.
Restarting against residual
field and opposite phase
All motors can be reclosed
against 100% residual field after
a system voltage failure.
Motor protection with PTC
thermistor
The motors are usually protected
by delayed terminal overload
protection devices (either circuit-breakers
for motor protection
or overload relays).
This type of protection is current-sensitive
and is particularly
effective under locked-rotor
conditions.
The motors can also be protected
by means of semiconductor
temperature sensors (thermistors)
embedded in the winding
and operating in conjunction
with a tripping unit (thermistor
motor protection) (Order Code
A11 or A12).
This type of protection is temperature-sensitive
and prevents
the motor windings from overheating,
e.g. due to sharply fluctuating
loads or frequent switching.
■All 1LA8 motors with the standard
design are fitted with 6
PTC thermistors for alarm and
tripping.
■The response temperature of
the PTC thermistors for the
1LA, 1MJ and 1LG motors corresponds
to class F.
In order to achieve full thermal
protection it is necessary to
combine a thermally delayed
overcurrent release and a PTC
thermistor. Full motor protection
implemented only with PTC
thermistors on request.
For type 1MJ motors:
Always use PTC thermistors if
the duty is anything other than
S1.
■PTC thermistors are absolutely
necessary if these motors are
used for converter-fed operation.
In this case, an additional
thermistor is fitted in the terminal
box for 1MJ6. Order Code
A15 or A16.
No additional anti-condensation
heater can be integrated in designs
with temperature sensors
and frame sizes up to 200 L.
Thermistor protection takes the
form of three PTC thermistors
connected in series and embedded
in the stator winding of
the motor. The 3RN1 tripping
unit which completes the system
must be ordered separately
– it is PTB certified. Further details
about its mode of operation,
circuitry, and price can be
found in Catalogue LV 10,
Order No.:
E86060-K1002-A101-A4-7600.
Pole-changing motors with two
separate windings need twice
the number of temperature sensors.
If an alarm signal is to be output
prior to the motor being shut
down, two groups of three temperature
sensors will be needed.
The alarm signal is usually
output at 10 K below shutdown
temperature.
Motor temperature detection
with temperature sensor
KTY84
See "Converter-fed operation"
Page 2/44.
Squirrel-cage motors
Technical information
Electrical features
Anti-condensation heating
Supply voltage 230 V
Order Code K45
Supply voltage 115 V
Order Code K46
Anti-condensation heaters can
be fitted to motors whose windings
are exposed to a risk of
condensation due to the ambient
climate, e.g. stationary motors
in a damp environment or
motors subjected to considerable
fluctuations in temperature.
An additional M16 x 1.5 or
M20 x 1.5 cable entry fitting is
provided in the terminal box for
the power supply cable.
The anti-condensation heater
must not be switched on while
the motor is running.
An alternative to anti-condensation
heaters (involving no extra
cost) is to connect a voltage of
around 4 to 10% of the motor
rated voltage to stator terminals
U1 and V1; 20 to 30% of the motor
rated current provide an adequate
heating effect (does not
apply to 1MA6 motors, frame
sizes 225 M to 315 L, 1LA8).
For 1MJ6 motors:
No built-in anti-condensation
heater is available for 1MJ6 motors
up to frame size 160 L when
equipped with PTC thermistors.
For 1MA . and 1LA . motors in
Zone 21:
No built-in anti-condensation
heater is available up to frame
size 200L.
For 1LA . motors in Zones 2 and
22:
Built-in anti-condensation heating
on request.
For motors Size Heat output (W) for Order Code
K45 (230 V) K46 (115 V)
1LA5,
1LA6,
1LA7,
á
â
ß
56 to 80
90 to 112
132 to 200
25
50
100
25
50
100
1LA9 ã 225
78
78
1LG4, 1LG6
1MJ6,
1MJ7/1MA6
á
â
ã
180 and 200
225 and 250
280 and 315
55
92
109/105
55
92
109/105
1LA8 all 200 183
1MJ8 315
100
100
355
200
200
1MJ1 355
250
250
400
250
250
450
280
280
1LG4/1LG6 180 and 200 48
48
in (E)Ex nA 225 and 250 92
92
280 and 315 105
105
Siemens M 11 · 2003/2004 2/17
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