Introduction of Alternator and Its Maintenance

8.1 Introduction of alternator

The alternator installed in the generator is the brushless excitation type, thus the maintenance of the slip ring and brush can be left out. The control system contains a automatic voltage regulator.

8.2 Maintenance of alternator

Though maintenance is seldom made according to the requirements, it is suggested to perform check and cleaning regularly.

According to the procedures provided by Manual for Alternator, the insulating property of the coil shall be tested at the first usage. If the generator is halted for standby application, then give stress on the humidity of the storage location. Generally speaking, test the insulation degree every 3-6 months. In the high humidity area, when the machine is not used, the heater shall be installed to drive away humidity, which will be conductive the dryness of the coil.

If the alternator is installed with air filter, then the regular observation shall be made according to the environment of the location. If it is necessary to clean it, then dismantle the materials of the filter to immerse or wash it: can add stain remover appropriately until the material is clean. Completely dry the materials before reinstallation.

More, the interior and exterior of the alternator shall be cleansed regularly. However, the frequency of cleansing depends on the environment of the location of the machine. When it is necessary to clean the alternator, please do it according to the following procedures. Disconnect all power supplies, wipe off the dust, dirt, oil deposit, water and any liquids and clean the ventilation net for these objects enter into the coil, they will make the coil become too hot cause damages to the insulation. The dust and dirt shall be absorbed with dust collector rather than cleaned with or air blow or high pressure water spray.

Notes: Alternate Manual provides further detailed maintenance data and guidance for search of faults.

9.1 Introduction and Distinguishing Methods of Control System

9.1.1 Introduction: a advanced designed electronic control system installed in the generator set is used to control and monitor this genset. According to demands of several types of generators, different control systems are prepared. They include: HGM6100 series, HGM6300 series and HGM6400 advanced starting system.

Control screen provides switching of the generator control to monitor its running and export, or in the emergent incident, the machine will be halted due to the too low of the oil pressure and high temperature of the cooling liquid. Any series are matched according to the requirements of installed generator.

As for the output circuit switch of the alternator, the switch will be automatically disconnected to protect output when overload or short circuit occurs to the circuit.

9.1.2 Distinguishing methods: any control system has a master controller with the type of the controller is marked on the shell of the master controller.

9.1.3 Control screen equipment: before starting generator set, the operation personnel should be familiar with the instruments and control components on the screen. When the machine runs, the operation personnel should observe the instrument or the display screen of the master controller from time to time. In doing so, the abnormal reading can be discovered to avoid the problems.

For instance, some auxiliary devices are added on the control screen. The control screen might have slight difference from the drawn representative pattern. The following descriptions will explain the function of each component on the control screen (there might be only a part of the component for different machine types.)

a) AC voltmeter-voltmeter displays the output of the alternator is AC voltage.

b) The selective switch of the AC voltmeter provides the voltages among the phases or between one phase and the zero line for the operator to select while OFF position is provided for the operator to perform zero setting when the machine runs.

c) AC ammeter-the voltmeter displays the currently transported AC current. However, the large or small current depends on the load. To measure the current of each phase, the ammeter can be used to select the switch. If the ammeter has no reading when the generator is running, then the selective switch of the ammeter might be at OFF position.

d) The selective switch of the AC ammeter-this switch can selectively measure the current of each phase while the OFF position can be adjusted to the zero position in case of start-up.

e) Frequency meter-frequency meter is used to display the frequency output by the generator. When the diesel engine keeps a relatively stable speed under the control of the adjuster, the normal output frequency shall be 50HZ or 60HZ (full load of generator). If only there is partial load, the frequency might be slightly higher than the normal frequency. This is decided by the reduction degree of the speed controller. Actually, when there is no load, the frequency shall be 52HZ or 62HZ; when the connected to the load, the frequency will be reduced; in case of full load, it shall be 50HZ and 60HZ.

f) Running time table-a time indicating how many running hours for starting the generator.

g) Water-temperature gauge-a temperature gauge connected to a sensor of the generator is used to monitor the temperature of cooling liquid of the engine. The normal operation temperature shall be close to 85℃ (185F). The operating water temperatures of the different types of diesel engines are different and shall be subject to the Manual for Diesel Engine.

h) Oil pressure gauge of the diesel engine-an instrument used to monitor the oil pressure of the generator starts working form the moment when the diesel engine is started. The normal oil pressure is about 35-60P, S and I/60HZ.

i) Indicator light-when the indicator light is on, it indicates that the protective circuit has perceived the indication situation, the red light indicates the system will be halted while the green light indicates power output when it is on.

j) Control switch has an emergency stop switch and a power switch.

9.2 Accessories and Escalation of Control System

A lot of different accessories can be installed with the control system to be adapted to some machine sets with special requirements. The following sections will introduce some usages and operations.

Floating charger: even if this charge is not started up for a period of time to maintain the voltage of the starting battery, there is no harm. The maximum charging current of this charger is 10AMP. It should be provided with continuous 220～240V electric supply. Generally speaking, the switch is not set to avoid disconnecting charger unintentionally. The control system will automatically switch the charger in case of starting up. The battery is charged by the diesel engine driven charger after the diesel engine is started. This charger is selected by the user.