14108242 Installation, operation and maintenance manual – Squirrel cage motor – WGM20 Line l 31
6
COMMISSIONING
When the motor is started for the first time or after a prolonged standstill, several aspects must be considered besides the
regular operation procedures.
ATTENTION
Avoid any contact with electric circuits;
Even low-voltage circuits may be life threatening;
In any electromagnetic circuit, overvoltages may occur under certain operating conditions;
Do not open an electromagnetic circuit suddenly, because the presence of an inductive discharge voltage
may break the insulation or injure the operator;
In order to open those circuits, disconnect switches or circuit breakers must be used.
6.1
PRELIMINARY INSPECTION
Before the first motor start or after long periods out of
operation, the following items must be inspected:
1.
Check if all the motor fastening bolts are tightened;
2.
Measure the winding insulation resistances, making
sure they are within the specified values;
3.
Check if the motor is clean and if the packages,
measuring instruments and alignment devices were
removed from the motor operating area;
4.
Check if coupling connecting components are in
perfect operating conditions, duly tightened and
greased, where necessary;
5.
Check if the motor is correctly aligned;
6.
Check if the bearings are properly lubricated. The
lubricant must be of the type specified on the
nameplate;
7.
Inspect connections and parameterization of
accessories and protections;
8.
Check if all electrical connections comply with the
motor connection diagram;
9.
The cables connected to the stator and rotor main
terminals must be properly tightened in order to
prevent their short-circuit or loosening;
10.
The terminal box covers must be correctly fastened;
11.
Inspect the operation of the motor cooling water
supply system;
12.
Motor air inlets and outlets must be unobstructed;
13.
The moving parts of the motor must be protected to
prevent accidents;
14.
Check if the power supply voltage and frequency
comply with the data on the motor nameplate;
6.2
FIRST STARTING
After all preliminary inspections have been carried out
proceed according to the directions presented next in
order to perform the first start of the uncoupled motor:
1.
Turn off the space heaters;
2.
Set the protections in the control panel;
3.
Turn ON the water cooling system, checking the
necessary flow and pressure, and the temperature of
the cooling water;
4.
Rotate the motor shaft slowly in order to check that no
part is being dragged or any abnormal noises are
occurring;
5.
Start the motor with no load, making sure that it
rotates smoothly without strange noises;
6.
Check the rotation direction with the motor uncoupled
from the load. In order to invert the rotation direction,
just invert the connection of any two phases;
7.
Keep the motor rotating at rated speed and write
down the bearing temperatures at 1-minute intervals
until they become constant. Any sudden increase in
bearing temperature indicates lubrication or friction
surface abnormality;
8.
Monitor the bearing temperatures and the vibration
levels. If there is a significant variation of any value,
interrupt the motor starting, identify possible causes
and make the necessary corrections;
9.
When the bearing temperatures stabilize, it is possible
to proceed to the other motor operation steps.
ATTENTION
The noncompliance with the procedures
described in section 6.2 may impair the
motor performance, cause damages and
even lead to its burnout, voiding the
warranty.
6.3
OPERATION
The operating procedures vary considerably depending on
the motor application and the type of control equipment
used.
Only the general procedures are described in this manual.
For the control system operating procedures, refer to the
specific manual of this equipment.
6.3.1
General
After a first successful starting test, couple the motor to
the driven load, and then the starting procedure can be
reinitiated, as follows:
Start the motor coupled to the load until its temperature
stabilizes and check for unusual noises, abnormal
vibrations or excessive heating. If significant vibration
variations occur regarding the initial operation condition
until the condition after reaching thermal stability, then it
is necessary to check the alignment and the leveling.
Measure the current consumption and compare it to
the value given on the nameplate.
In continuous duty, without load variation, the measured
current must not exceed the value indicated on the
nameplate multiplied by the service factor;
All the instruments and devices for measurement and
control must be permanently monitored to detect
occasional alterations, determine their causes and
make the proper corrections.
