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Technical Precautions for Design, Installation and Maintenance www.rulmecacorp.com
TC101: 03/07
76
Technical Precautions for Design, Installation and Maintenance
The precautions below will enable conveyor engineers, system integrators, and end users to properly design,
install, operate, and maintain conveyor systems using Rulmeca Motorized Pulleys. Ignoring any of the pre-
cautions may result in pulley damage and will void the product warranty. Precautions which could effect war-
ranty coverage are marked with a warning symbol, as shown.
Use these technical precautions with the Rulmeca Bulk catalog entitled Motorized Pulleys for belt conveyors
TC-101.
Contents
Page
1
Actual Belt Speed vs. Nominal Belt Speed.............................................................................................................
77
2
Aftermarket Service................................................................................................................................................
77
3
Ambient Temperature.............................................................................................................................................
77
4
Belt Alignment........................................................................................................................................................
78
5
Belt Pull..................................................................................................................................................................
78
6
Belt Tension............................................................................................................................................................
78
7
Capacitors for Single Phase Motors.......................................................................................................................
78
8
Clearance...............................................................................................................................................................
78
9
Electrical Installation...............................................................................................................................................
79
10 Electromagnetic Brake...........................................................................................................................................
79
11 High Duty Cycle......................................................................................................................................................
79
12 Lagging Limitations................................................................................................................................................
80
13 Lagging Specifications............................................................................................................................................
80
14 Mechanical Backstops............................................................................................................................................
81
15 Motor Current Overload and Overcurrent Protection.............................................................................................
81
16 Motor Thermal Protection.......................................................................................................................................
81
17 Motorized Pulley Mounting Orientation..................................................................................................................
82
18 Mounting Brackets..................................................................................................................................................
82
19 Non-belt, Partial Belt, Modular Belt........................................................................................................................
83
20 Oil and Oil Seal Maintenance.................................................................................................................................
83
21 Pulley Diameter......................................................................................................................................................
84
22 Regreasable Labyrinth Seals.................................................................................................................................
84
23 Repair and Mechanical Maintenance.....................................................................................................................
84
24 Reversing Conveyors.............................................................................................................................................
84
25 Surface Coating......................................................................................................................................................
85
26 Storage of Motorized Pulleys.................................................................................................................................
85
27 Start-up...................................................................................................................................................................
85
28 Terminal Box...........................................................................................................................................................
85
29 Transport and Handling..........................................................................................................................................
86
30 Variable Frequency Drive.......................................................................................................................................
86
31 International Protection (IP) Ratings......................................................................................................................
89
32 Oil Quantities..........................................................................................................................................................
90
33 Oil Specifications....................................................................................................................................................
91
34 Wiring Diagrams..................................................................................................................................................... 92-100 www.rulmecacorp.com
TC101: 03/07
77
1) Actual Belt Speed vs. Nominal Belt Speed:
Two key specifications for each Motorized Pulley are power (HP) and nominal belt speed, as shown on indi-
vidual specification pages in this catalog.
Nominal belt speed is a design target, providing consistent choices among all models and powers. For exam-
ple, a nominal belt speed of 300 fpm is available in most pulley models.
Actual full load belt speed is almost never exactly equal to nominal belt speed.
Actual belt speed is a function of the motor pole number, gear ratio, and load. Therefore, this catalog displays
actual full load belt speed at 60 Hz, as well as nominal belt speed, to assist designers who need more precise
belt speeds.
Note that all belt speeds shown in this catalogue refer to unlagged pulleys because:
1. Belt speed for each model is a function of pulley diameter,
2. Pulleys are available with and without lagging,
3. Lagging changes the pulley diameter, and
4. Various lagging thicknesses are available.
Note that each Rulmeca Motorized Pulley for a three-phase power supply uses an asynchronous squirrel
cage induction motor with approximately 5% slip. In a no load condition, motor RPM is nearly equal to syn-
chronous speed RPM. The slip rate is dependent on power and design of the motor. Low powered motors
have a lower slip rate than high-powered motors. At full load, the motor RPM is approximately 5% less than
synchronous.
The actual belt speed displayed in this catalogue is based on an unlagged pulley running at full load, nom-
inal voltage (e.g. 460 volts) and 60Hz.
The actual full load belt speed of a lagged pulley running at
1. Full load,
2. Nominal voltage (e.g. 460 volts),
3. 60 Hz
equals the actual full load belt speed specified in this catalogue, times the ratio of the lagged/unlagged pulley
diameters.
Example: A 320M Motorized Pulley (with an unlagged pulley diameter of 12.64) at 5.5 HP and nominal belt
speed of 150 fpm has an actual belt speed of 157 fpm at full load, nominal voltage, and 60 Hz. If
this pulley is supplied with 1/4 thick lagging, the lagged pulleys actual belt speed equals 157 fpm
x (13.14/12.64) = 163 fpm at full load, nominal voltage, and 60 Hz.
The maximum no load belt speed of this lagged pulley is 5% higher than the full load belt speed (i.e. no load
belt speed = 163 fpm x 1.05 = 171 fpm.
2) Aftermarket Service
Always contact your local authorized Rulmeca service center or distributor for aftermarket service.
Or contact Rulmeca at www.rulmecacorp.com
3) Ambient Temperature:
Motorized Pulleys are normally cooled by dissipating heat through contact between the surface of the pul-
ley and the conveyor belt. It is essential that each pulley have an adequate thermal gradient between the pul-
leys motor stator and its ambient operating temperature.
All Motorized Pulleys in this catalog are designed and tested under full load (without rubber lagging) for use in
a max. ambient temperature of +104
o
F with standard Class F motor. Motorized Pulle