WEG S Series - Operation; Operation Procedures; Resynchronization; Data Recording

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11866576 Installation, Operation and Maintenance Manual – Synchronous Motors – S Line – Brushless – Horizontal l 37
A
TTENTION
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
6.3.1 Operation procedures
After a first successful starting test with no load, couple
the motor to the driven load and then perform the starting
and operation as follows:
1. Turn off the space heater;
2. Set the protections in the control panel;
3. Switch on the hydraulic unit (if any);
4. Switch on the oil circulation system of the bearings (if
any); Check the level, flow and pressure of the oil,
making sure that they comply with the data on the
nameplate;
5. The pressure or flow return signal of the oil
circulation system in the bearings must be
confirmed, making sure that the oil has reached the
bearings;
6. Start the industrial water cooling system, checking
the required flow and pressure (motors with air-water
heat exchanger);
7. Turn on the fans (motors with forced ventilation);
8. Switch on the high-pressure oil injection system (if
any), keeping it on as informed in the motor technical
documentation, until the bearings can get the
lubrication by self-pumping;
9. Run 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 in the set after
the temperature stabilizes, it is necessary to check
the alignment and the leveling;
10. Measure and compare the consumed electric
current to the value indicated on the nameplate. In
continuous duty, without load oscillation, the value of
the current measured must not exceed the value
indicated on the motor nameplate multiplied by the
service factor;
A
TTENTION
A
ll the control and measurement instruments
must be monitored permanently so that
occasional changes will be detected
immediately and their causes solved before
proceeding with the operation.
6.3.2 Resynchronization
If the motor loses synchronism, the excitation circuit will
present a field current above the normal value of the
motor, supplied by the excitation panel before this
operating condition.
To put the motor back to synchronism, it is necessary to
disconnect the field power supply for a period of two to
three seconds after the synchronism loss.
If the motor control system is adjusted for
resynchronization after the loss of synchronism, the
following criteria must be observed:
1. Disconnect the field supply for at least two seconds
in order to allow the motor induced field current to
activate the discharge circuit and/or the insertion of
the discharge resistor and, thus, reduce the transient
torques during resynchronization.
2. The resynchronization time must not exceed the
motor normal start sequence time.
3. Normally, the removal of the excitation is necessary
for a successful resynchronization;
4. The motor control panel must distinguish start failure
from loss of synchronism, so that an attempt of
resynchronization will not occur immediately after a
start failure.
5. The quantity and the duration of resynchronization
attempts must be limited according to each motor
project.
6.3.3 Data recording
The following data must be collected and recorded
periodically during the motor operation:
 Temperature of the bearings;
 Oil level of the bearings;
 Stator winding temperature;
 Air inlet and outlet temperatures;
 Vibration level;
 Field and stator voltage and current.
At the beginning of operation, the values must be
checked every fifteen minutes. After some hours of
operation, check these values every hour. After some
time, these intervals may be progressively increased, but
those values must be recorded daily for a period of five to
six weeks.
6.3.4 Temperatures
 The temperature of the bearings, stator winding and
ventilation air (if any) must be monitored while the
motor is operating.
 The temperature of the bearings and stator winding
stabilize in a period between four to eight hours of
operation;
 The stator winding temperature depends on the motor
load condition. Therefore, its operation data (voltages,
currents, frequency) must be monitored during the
motor operation.
6.3.5 Bearings
The system start, as well as the first hours of operation,
must be monitored carefully.
Before putting the motor operation, verify:
 If the high-pressure oil injection system (if any) is ON;
 If the external lubrication system (if any) is ON;
 If the used lubricant complies with all specifications;
 The lubricant characteristics;
 The oil level (oil-lubricated bearings);
 If the bearing alarm and trip temperatures are set;
During the first starting, it is important to pay attention to
abnormal vibrations or noises. If the bearing is not
running silently and smoothly, the motor must be shut
down immediately.