FAULT FINDING MANUAL PPOINT

1 FAULT FINDING MANUALFor Self Excited and Separately Excited GeneratorsSAFETY PRECAUTIONSB efore testing the generating set, read the generating setInstallation MANUAL , and this FAULT FINDING MANUAL , and becomefamiliar with it and the AND EFFICIENT OPERATION CAN ONLY BEACHIEVED IF THE EQUIPMENT IS CORRECTLYINSTALLED, OPERATED AND accidents occur because of a failure to follow fundamentalrules and SHOCK CAN CAUSE SEVEREPERSONAL INJURY OR DEATH. Ensure installation meets all applicable safety and localelectrical codes.

2 Have all installations performed by qualifiedInstallation technicians. Do not operate the generator with protective covers, accesscovers or terminal box covers removed. Disable engine starting circuits before carrying outmaintenance. Disable closing circuits and/or place warning notices on anycircuit breakers normally used for connection to the mains orother generators, to avoid accidental all IMPORTANT, CAUTION, WARNING, and DANGER notices, defined as:Important ! Important refers to hazard or unsafe methodor practice, which can result in productdamage or related equipment !

3 Caution refers to hazard or unsafe method orpractice, which can result in product damageor personal refers to a hazard or unsafe methodor practice, which CAN result in severepersonal injury or possible refers to immediate hazards, whichWILL result in severe personal injury to our policy of continuous improvement, details in this MANUAL which werecorrect at time of printing, may now be due for amendment. Information includedmust therefore not be regarded as "LIVE" EQUIPMENTIt is essential that all test instruments areregularly checked for safety, and anyconnection leads, probes, or clips.

4 Arechecked to ensure that they are suitable forthe voltage levels being attempt to test a "LIVE" generatorunless there is another competent personpresent who can switch off the power supplyor shut down the engine in an expose "LIVE" connections unless youhave created a safe working area around sure you have made all other persons inthe immediate area fully aware of what youare FINDING MANUALSECTION 1 Recommended Metering and Test InstrumentsSECTION 2 Electrical TerminologySECTION 3 FAULT FINDING method A , for All GeneratorsSECTION 4 FAULT FINDING method B , for Self-Excited Voltage Regulator is powered from the Generator 5 FAULT FINDING method B , for Separately Excited GeneratorsAutomatic Voltage Regulator is powered from the Permanent Magnet 6 Parallel Operation and FAULT FINDING for All Generators4 SECTION 1 RECOMMENDED METERING AND TEST INSTRUMENTSTo successfully carry out the various test procedures suggestedin this MANUAL , certain test instruments are essential.

5 Thefollowing lists detail the basic requirements in this should be noted that in addition to these instruments acomprehensive kit of tools is also essential. For FAULT findingpurposes this need not include any specialised 1 - MultimeterThe Multimeter is a comprehensive test instrument for measuringvoltage, current and resistance. It should be capable ofmeasuring the following ranges:-Voltage A C0-250-500-1000 VoltsVoltage D C0-25-100-250 VoltsAmperes D C0-10 AmpsD C Resistance0-10k (ohms) or 0-2k (ohms)0-100k (ohms) or 0-20k (ohms)0-1M (ohms) or 0-200k (ohms)Item 2 Tachometer or Frequency meterThis instrument is for measuring the shaft speed of the alternatorand should be capable of measuring speeds between 0 and 5000revolutions per minute, (RPM).

6 An alternative to the tachometer is the frequency meter (seeSection 2 on Frequency and Speed, for details). However thealternator must be generating its normal output voltage for thisinstrument to be 3 Megger (Insulation test meter)This instrument generates a voltage of 500V or 1000V, and isused to measure the resistance value of the insulation to earth(ground). It may be an electronic push button type, or a handcranked generator 4 - Clip-On Ammeter (Clampmeter)Used to measure A C current, it consists of a pair of callipers,which are clamped around the conductor, and by means of atransformer action, gives an indication of the amperes flowing inthe conductor.

7 Useful ranges to have on this meter are:-A C Amps 0-10-50-100-250-500-1000 Item 5 Kelvin Bridge low resistance meterThis instrument is used to measure resistance values below They are bulky, and expensive, but are the only means ofaccurately measuring very low resistances, such as main statorand exciter rotor , there are other methods of testing low resistancewindings, and these are included in the various test procedures, Test Method A (Section 3). This section will enable the maingenerator windings to be tested while running the generator atnormal speed without is essential that all test instruments beregularly checked for safety, and anyconnection leads.

8 Probes or clips checked toensure that they are suitable for the voltagelevels being attempt to test a "LIVE" generatorunless there is another competent personpresent who can switch off the power supplyor shut down the engine in an expose "LIVE" connections unless youhave created a safe working area around sure you have made all other persons inthe immediate area fully aware of what youare kVA to kVADo not attempt to carry out tests on mediumor high voltage generators without usingspecialised instruments and probes, withsuitable protection equipment andprocedures for grounding (earthing) theoutput 2 ELECTRICAL TERMINOLOGY AND RESISTANCESVOLTAGE AND CURRENT (AMPERES)An AC Generator is designed to produce a voltage level suitablefor the load to which it is connected.

9 The control circuits aredesigned to automatically maintain this voltage level as the loadis increased or large changes in loading will produce temporary changesin the voltage. The control circuit is designed to recover to astable condition as quickly as current drawn from the AC Generator is determined by theamount of load connected to it. Current creates a temperaturerise in the windings, hence the requirement for drawing airthrough the AC Generator by means of the fan.

10 If the full loadrated current is exceeded on any phase of the main statorwindings, it will result in overheating in this winding. Similarly, anyrestriction in the flow of air through the machine will result in arapid increase in the temperature of the (Hz) and Speed (RPM)An AC Generator is a constant speed device, and should not beoperated at speeds above 4% of the rated speed, or more than1% below the rated changes will create temporary changes in the speed, butthe engine must be capable of returning to the steady statecondition within a few speed requirements for the AC Generator are determinedby.