Space Heater; Auxiliary Winding Protection; Diodes Protection; Protection Against Underfrequency - WEG G Serie Manual De Instalación, Operación Y Mantenimiento

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Table 4.7: Maximum temperature of the bearings
BEARINGS
Maximum temperature of protection setting (ºC)
Alarm
110
ATTENTION
The temperature alarm and shutdown can be
set based on experience, but must not
exceed the maximum rate indicated in the
Table 4.6 and Table 4.7.
4.6.2

Space heater

When the alternator is equipped with a heater to prevent
condensation of water for long periods without operation,
they must be programmed to be always energized after
the shutdown of the alternator and be deenergized
before the switch goes into operation.
The dimensional drawing and an existing specific
identification plate on the alternator indicate the value of
supply voltage and power of the installed space heaters.
ATTENTION
If the space heaters remain energized while
the machine is in operation, the winding may
be damaged.
4.6.3

Auxiliary winding protection

The alternator has a protection fuse, connected in series
with the auxiliary winding or the voltage regulator, with
the function of protecting it against overload.
ATTENTION
Failure to use the specified fuse may result in
burning of the auxiliary coil and hence of the
stator winding. This defect is not covered
under warranty.
In case of operation of the fuse it is necessary to replace
it with another of equal value, so that the alternator
operates properly protected.
The fuse protects the alternator and voltage regulator in
the following situations:
1. Loss of reference (feedback) of the voltage regulator;
2. 4. Connection of the cables of the auxiliary coil in
short circuit, done on output cables of the coil or by
erroneous connection on the voltage regulator;
3. Connection of the output terminals of the voltage
regulator in short circuit;
4. Operation at low speed (used to heat the diesel
engine), especially with the function U / F voltage
regulator disabled, depending on the operating
condition (rotate, adjust the regulator and others);
5. In case of damage to the voltage regulator (burning of
the power element or internal reference failure in the
circuitry for comparison);
26 l Installation, operation and maintenance manual – Synchronous Alternator – G line - Horizontal
Shutdown
120
The fuse does not operate in case of short circuit of the
alternator phases. In these cases, the protection should
be done with a relay, allowing the motor starting and
protection sensitization.
4.6.4

Diodes protection

The diodes are protected against overvoltage and / or
power surge, according to Table 4.8.
In case of failure of these components, they must be
replaced.
Table 4.8: Protection of the diodes
GTA161 - GTA252
GTA311 - GTA561
Type of assembly
Item (WEG) 10049848
1W, 745Vcc,
Features
550Vca 210J/2ms
4.6.5

Protection against underfrequency

The protection against underfrequency avoids
overcurrent in the auxiliary coil windings and excitation
circuit of the alternator. The setting should in the U/F
trimpot of the voltage regulator.
4.6.6

Maintenance of the short-circuit current

The G line WEG alternators are manufactured with the
auxiliary coil inserted into the main stator slots, isolated
from the main winding. This coil is designed to power the
voltage regulator power circuit and maintain the alternator
short-circuit current.
NOTE
1. Due to the fact of the alternator to keep
high Icc, an overcurrent relay must be
provided and to open the main breaker in
no more than 20s, under risk of burning
the alternator.
2. To maintain the short circuit current above
3.0 x In, refer to WEG.
Varistor Capacitor

 
THT THT
10391625
0,1µf, 2000Vcc,
630Vca
10680382