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Mechanical design
General
The roller table motors supplied by ABB are squirrel
cage motors which are specially designed for use
with frequency converters. Robust in construction,
the motors are fully sealed to withstand the tough
conditions in rolling mills.
The motors are low speed units intended for direct
connection to rollers. The pole number and frequency
can be selected, avoiding the need for gearboxes and
therefore saving on maintenance costs and increasing
the overall efficiency of the drive.
Assembly dimensions and shaft heights are in
accordance with IEC 60072-1. The normal motor
mounting position is B3/IM1001. Flange mounting (IM
B5/IM3001) is possible for frame sizes 180-250 on
request.
The enclosure of the motors is protected to IP55.
Higher degrees of protection, up to IP 65, are also
available. If required, the stator frame of M3RP motors
can be pressurized with air to prevent any ingress of
water or dust.
ABB offers roller table motors in sizes 180 to 450, with
smaller sizes available on request.
Roller table motors
Technical data for totally enclosed squirrel
cage three phase motors
IP 55 – IC 410 – Insulation class F, temperature rise class B
Motors and frequency converters - solutions for rolling mills
that incorporate ABB's wealth of application know-how
ABB meets the demands of the rolling mill environment
by combining the expertise of two areas within the
Group. By bringing together squirrel cage motors from
ABB Motors and frequency converters from ABB Drives,
ABB can supply electrical drive systems that are
tailored to the needs of the industry.
ABB Motors has been developing and growing for
over 100 years and is today one of the world’s leading
manufacturers of low voltage induction motors. It
supplies a full range of industrial electric motors,
meeting the needs of most applications with virtually
any power rating. At the same time it provides solid
value and commitment to its customers through
unrivalled service and back-up.
ABB Drives is the leading manufacturer of AC and DC
drives for all types of demanding applications. For low
voltage multimotor systems, ABB supplies AC drives up
to 5600 kW.
Through its unrivalled experience in AC and DC drive
design, manufacture, installation and commissioning,
ABB has acquired a vast reserve of know-how for
specific applications.
One of these applications is the rolling mill, where the
extremely harsh environment and tough production
process demand the best in AC drive technology. An
example of this superior technology is ABB’s DTC
controlled ACS800 multidrive frequency converter,
which has received excellent feedback from users in
roller table applications.
ABB has invested heavily in research and development,
ensuring that each generation of induction motors and
frequency converters keeps pace with the rising needs
of the metal industry. The products are known for their
efficiency, robustness and reliability – characteristics
which combine to deliver the maximum possible value
for customers.
The motors feature a number of mechanical solutions
that have been designed for the extreme conditions
found in rolling mills.
The standard shaft end is of cylindrical construction.
Conical shaft ends, as well as double shaft extensions,
are available on request.
Robust, die-cast aluminum squirrel cage rotors, which
are highly wear-resistant, are used throughout the
motor range. The rotor slot design is optimized for
frequency converter applications.
The frames and bearing end shields are made of cast
iron. Spheroidal graphite cast iron is used as standard
in frame sizes 355-450, and is available on request
for smaller frame sizes. All fixing screws and bolts are
locked.
The motors are totally enclosed, frame cooled motors,
with no external cooling fan, in accordance with IEC
60034-6, IC 410. The stator frames have crosswise
vertical cooling ribs, allowing optimum heat flow away
from the motor surface.
A water-cooled version is available on request.
Positions 1 to 4
3GRP = Totally enclosed fan cooled squirrel cage
motor with cast iron frame
Positions 5 and 6
IEC-frame
18 = 180 28 = 380
20 = 200 31 = 315
22 = 225 40 = 400
25 = 250 45 = 450
Position 7
Speed (Pole pairs)
3 = 6 poles
4 = 8 poles
5 = 10 poles
6 = 12 poles
Position 8 to 10
Serial number
Motor size
A B C D, E, F, G
M3RP 280MB 3GRP 283 320 - A D G 003 etc.
1 2 3 4 5 6 7 8 9 10 11 12 13 14
A Motor type
B Motor size
C Product code
D Mounting arrangement code
E Voltage and frequency code
F Generation code
G Variant codes
Position 11
- (dash)
Position 12
Mounting arrangement
A = Foot-mounted, top-mounted terminal box
B = Flange-mounted, large flange
H = Foot- and flange-mounted, terminal box
top-mounted
Position 13
Voltage and frequency code
See table below
Position 14
Generation code
A, B, C...
The product code must be, if needed, followed by
variant codes.
Roller table drives
Roller tables incorporate a number of motors, the speed
of which can be steplessly controlled by one or more
frequency converters.
The rolling mill environment places severe stress on
roller table drives. As plates and billets travel along
the roller table at high speeds, the motors driving the
rollers are subjected to high torque loads. At the same
time, the reliability of the drive system is constantly
threatened by the high ambient temperature, humidity,
and the risk that fine dust particles from the process
could infiltrate the motors.
To meet these rigorous demands, ABB has developed
its Roller Table AC Drive System, which comprises the
new, robust M3RP induction motors, together with ABB
frequency converters.
The totally enclosed construction of the M3RP induction
motors renders them immune to the ingress of moisture
and dust. The power factor of ABB frequency converters
with IGBT supply units is 1.0 under any load conditions.
Together the motor and frequency converter provide a
competitive solution, with high availability and minimal
maintenance costs.
Roller table motors in brief, basic design
Motor size 180 200 225 250
Stator Material Cast iron EN-GJL-200 / GG 20 / GRS200
Paint colour shade Blue, Munsell 8B 4.5/3.25 / NCS 4822 B05G
Paint Two-pack epoxy paint, thickness r 70 Mm.
Bearing end shields Material Cast iron EN-GJL-200 / GG 20 / GRS200
Paint colour shade Blue, Munsell 8B 4.5/3.25 / NCS 4822 B05G
Paint Two-pack epoxy paint, thickness r 70 Mm.
Bearings D-end 6310/C3 6312/C3 6313/C3 6315/C3
N-end 6309/C3 6310/C3 6312/C3 6313/C3
Axially-locked bearings Inner bearing cover As standard, locked at D-end
Bearing seal Labyrinth seal
Lubrication Regreasable bearings, regr. nipples M10x1
SPM-nipples As standard
Rating plate Material Stainless steel, EN 10088, thickness 0.5 mm
Terminal box Frame material Integrated with stator frame
Cover material Cast iron EN-GJL-200 / GG 20 / GRS 200
Screws Steel 8.8, zinc electroplated and yellow chromated
Connections Cable entries 1xM32 + 1xM20 1 x M40 + 1 x M20
Terminals 3 terminals for connection with cable lugs(not included)
Stator winding Material Copper
Insulation Insulation class F
Winding protection 3 PTC thermistors as standard, 150 °C
Rotor winding Material Pressure die-cast aluminum
Balancing method Half key balancing as standard
Key ways Closed keyway
Heating elements Optional 50 W
Drain holes Standard, open on delivery
External earthing bolt As standard
Enclosure IP 55, higher protection on request
Cooling method IC 410
