Alternator Training

Training Department

ALTERNATOR TRAINING Ersin ERDALI June’ 06

INCLUDE OF OF ALTERNATOR ALTERNATOR TRAINING TRAINING INCLUDE 1. Base Electrical Information 2. Alternator Operation Principle 3. Alternator Parts and Functions 4. Technical Knowledges and Numeral Rules 5. Protection Class (IP,H-F) 6. Troubleshooting Guide Ersin ERDALI

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1. Base Electrical Information Electromagnetic Field :

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1. Base Electrical Information

Faraday’s Law :

Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.

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1. Base Electrical Information Electrical Definations:







Resistance, Unit : Ohm (R)  Resistance is a measure of the degree to which an object opposes the passage of electric current  Measurement Device : Ohmmeter Voltage, Unit : Volt (V)  Voltage is the difference of electrical potential between two points of an electrical network  Measurement Device : Voltmeter Current, Unit : Ampere (A)  Moving electrons by voltage and flowing electrons  Measurement Device : Ampermetre 18 electron /s  1 Ampere : 6,28x10 Ersin ERDALI

V  IxR Circuit Component

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1. Base Electrical Information • Alternating Current (AC) :

• Direct Current (DC) :

AC current is changed way and strenght by the time.

DC current is not changed way and strenght by the time.

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2. Alternator Operation Principle  When the magnetic field around a conductor changes, a current is induced in the conductor. In a alternator, a rotating magnet called the rotor turns within a stationary set of conductors wound in coils on an iron core, called the stator. The field cuts across the conductors, generating an electrical current, as the mechanical input causes the rotor to turn. Permanent Magnetic Field Ersin ERDALI

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2. Alternator Operation Principle

 Vector sum of the magnetic field vectors of the stator coils produces a single rotating vector of resulting rotating magnetic field.

 Sine wave current in each of the coils produces sine varying magnetic field on the rotation axis. Magnetic fields add as vectors. Ersin ERDALI

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2. Alternator Operation Principle  Magnetic field on the windings induce voltage in main stator.

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alternating (AC)

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2. Alternator Operation Principle  Voltage regulator senses induced voltage in main stator to take a referance.  Sensed voltage compares regulator setting values (400 V AC, 50Hz).  Excitation voltage realize excitation stator via excitation toes of regulator according to the difference

Uyartýn Gerilimi DC

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Referans Giriºleri

Set Deðerleri

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2. Alternator Operation Principle  Diodes rectify DC voltage to induced AC voltage in excitation rotor to increase permanent magnet in main rotor.  Excitation rotor voltage realizes main rotor windings which rectified DC voltage.

Inputs of Diodes Excitation Rotor Voltage AC Output of Diodes Main Rotor Voltage DC

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3. Alternator Parts and Functions

Alternators Which We Use : Stamford / England (12 toes) Mecc-Alte Spa / Italy

Eco series 12 toes (Out of Eco 28)

Leroy-Somer / France Ersin ERDALI

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3. Alternator Parts and Functions Terminal Box Alternator

Stator

A.V.R.

Main Rotor

Rotating Diodes Plate and Varistor

Excitation Rotor Ersin ERDALI

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3. Alternator Parts and Functions Alternator Parts (MccAlte Eco 37) : NAME 1 real seal 2 casing 3 grid 5 users terminal board 7 rear cover 8 frame with stator 9 front cover 9A front cover MD 35 10 exciting stator 11 rotating diode bridge 12 hub 13 exciting armature 14 rotor 15 fan 16 exterior flange bearing cover 17 drive-end bearing 18 interior flange bearing cover 19 rear bearing 20 terminal box 22 diode holder washer Ersin ERDALI

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23 electronic regulator

24 auxiliary terminal board 28 cover stay bolt

39 protection screen 40 fixing ring

42 parallel device 59 coupling hub 60 disc plates

70 radio disturbs suppressor 94 rear case

95 termin.brd.side panel

96 termin.brd.front panel 97 termin.brd.rear panel

98 regulator carrying panel

99 disc blocking ring spacer

104 component-carryng panel 123 ring spacer

143 exciter stay bolt 14


Terminal Box (Mecc Alte ECO 34) Neutral Point Paralleling

Transformer

Output Points

U- V- W RFI Suppressor

A.V.R. Ersin ERDALI

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Terminal Box (Mecc Alte ECO 3) R.F.I. Suppressor

Output Points

A.V.R.

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Terminal Box (Stamford P7 Series) : Terminal Box

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3. Alternator Parts and Functions Main Stator : • Main stator which is made of high quality siliceous laminations is mounted by means of supporting ribs in a sheet steel body.

• Main stator grooves and main rotor poles are designed to minimize distortion on the waveform. Main stator windings have a shortened pitch to reduce the harmonic effects on the waveform. Ersin ERDALI

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Main Rotor :

The rotor is salient-pole type. Damper windings are placed into the rotor as a standard feature for parallel work and unbalanced loads. Fan, the main rotor, excitation rotor and the rotating diodes are fitted to shaft . The entire rotor is dynamically balanced.

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Voltage Regulator (AVR) :

 This is the most important element of the alternator. At asymmetrical loads, the voltage regulator senses three phases as a reference therefore maximum voltage asymmetry is 5%. Electrical and thermical tests are applied before mounting on the alternator. The output voltage could be adjusted manually by a potentiometer. Reference (Sensing)

Alternator

LOAD

Voltage Regulator Setting Values Ersin ERDALI

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Voltage Regulator (AVR) :

 To remotely regulate the voltage there are terminals for potentiometer connection.

Electronic Voltage Regulator (UVR 6 Mecc Alte)

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Voltage Regulators Which We USe : Mecc Alte  

SR 7 UVR 6

Stamford 

SX 460



MX 341

S : Self excited

SX 440 MX 321

M : Permanent Magnet Generator

SX 421

SA 465

MA 325 Ersin ERDALI

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Mecc Alte UVR6 Voltage Regulator Technical Features:

• • • • • •

170-270 V AC Supply (with + and 2) Capability to sense 3 phases or 1 phase Stable for humidity and vibration Maximum voltage drop 15% Capability to set voltage-stability Protection for low frequence and over current

Delay over current protection

Yellow Led

Nominal operation

Green Led

Low frequence protection

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Red Led

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3. Alternator Parts and Functions Mecc Alte SR7/2 Voltaj Regulator Setting Potentiometer :

Voltage Setting Stability Setting Factory Settings (Low speed and over load)

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3. Alternator Parts and Functions Mecc Alte SR7/2 Voltage Regulator Terminal Connections :

Terminal 1 : Excitation windings negative (-) toe. Terminal 2 : It should bridge terminal 3 If SR7/2 regulator supply will be lower then 160 V AC. Terminal 3 : Excitation windings positive (+) toe and regulator supply. Terminal 4 : Regulator reference voltage. Terminal 5 : Common toe for regulator supply, regulator reference voltage and external potentiometer connection. Terminal 6 : To bridge terminal 5 for 60 Hz. Terminal 7 : External potentiometer connection. Ersin ERDALI

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Stamford SX440 Voltage Regulator Technical Features :   



 

Supply voltage 170-250 Vac Frequence 50-60 Hz nominal Output voltage max. 90 Vdc (207 Vac input) Output Current 4 A DC (max. 10 seconds 6 A DC) Regulation ±%1 Operation Temp. -40°C - +70°C Ersin ERDALI

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Stamford MX321 Voltage Regulator Terminal Connections - 1 :

 Volts:

Setting generator output voltage.

 Stability:

Keeping from voltage oscillation, setting steady state time .

 Stability Selection:

To provide suitable voltage transient.

 UFRO:

Setting underfrequence protection border.

 Frequency Selection:

Providing for suitable operation of UFRO protection.

 Droop:

Enable voltage droop (5 % on full load).

 Trim:

To provide regulator input and accessories uotput.

 Exc Trip :

Over excitation cutting level (5Vdc - %5, 8-15 s delayed). Ersin ERDALI

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Stamford MX321 Voltage Regulator Terminal Connections - 2 :  DIP:

Setting frequence-voltage curve.

 Over/V:

Shuting down excitation voltage When Ýnput reference voltage to AVR faults (Between terminal E1-E0; 300 Vac, 8-15s delayed).

 I-Limit:

Maximum short circuit current.

 Dwell:

Voltage tidy up time after on full loaded.

 RMS: Loading.

 RAMP:

Setting to reach nominal value of output voltage by cranking. Factory setting is 3 seconds and it’s enough for many applications. Ersin ERDALI

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External Voltage Potentiometer Connection :

• Voltage potentiometer can be connected terminal 1-2 of all AVR for Stamfor alternator. • Normally those terminals are bridged. Remove those bridge when potentiometer connected. • POT = 4,7 K

Stamford MX321 Voltage Regulator Ersin ERDALI

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Rotating Diode Plate :

•Ac voltage is rectified DC voltage to set the permanent magnet on main rotor via rotating diodes plate which induce excitation rotor. • Rotating diode plate is partitioned positive and negative plate and there are 3 diodes both plates (total 6 diodes). Rotating Diode Plate Elements : 1. AC Input 2. Rectifier Plate 3. Diodes – 3 x Negative 4. Diodes – 3 x Positive 5. Varistor 6. DC Output to Main Rotor 7. Plate Ersin ERDALI

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Varistor :

Varistors (VDR’s) are a mix of carbon materials that are a high resistance until subjected to a high pressure. They then becomes a low resistance path to bleed away excessive pressure by allowing lots of amps to momentarily flow through the VDR, which has become a momentary low resistance path. This means that the rating of the device based on it only being asked to conduct for very short period of time and very intermittently. A VDR that is continually 'clipping‘ excessive voltages will get hot and fail.

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Excitation Stator and Rotor: • Excitation stator is provided to induce magnet for excitation rotor by DC signal via voltage regulator (10-15 V). •On excitation rotor AC voltage is rectified DC voltage via rotating diodes plate and varistor. Thus DC Current is induced for permanent magnet for main rotor. Ersin ERDALI

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Voltage Regulator Supply Devices - 1 :

PMG

• Provides a separate fixed source impedence power to AVR & exciter field that is isolated from the generator output and is not influenced by external load conditions. • The isolated PMG power supply of the excitation system allows the generator to meet low EMI / RFI suppression levels to meet MILSTD.461C&VDE Class K.

• PMG provides constant power to supply manual voltage control of the generator & to supply overvoltage , overcurrent & over excitation protection circuits.

•Stamford and Leroy-Somer alternators have got PMG system which we use. Ersin ERDALI

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Voltage Regulator Supply Devices - 2 : AREP

It is auxiliary windings system to induce AC voltage to supply AVR which is inserted the main stator windings. Auxiliary windings are thin section. Resistance is lower than main stator windings. Mecc Alte alternator has got AREP windings system which we use.

Shunt

AC voltage is provided directly by main stator windings to supply AVR. Ersin ERDALI

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Voltage Regulator Supply Devices - 3 : When to Choose PMG or AREP :       

Whole installation with several circuits Power cut forbidden High rate of distorting loads. Starting of a big motor Marine, hospitals, stand-by duty, standards in some countries. Arep minimum length required PMG existing shunt machine to be upgraded

When to Choose SHUNT :  Single circuit installation  Power cut acceptable  Self protection alternator Ersin ERDALI

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3. Alternator Parts and Functions SITUATION OVERLOAD OR SHORT CIRCUIT ON THE INSTALLATION

AREP

PMG

AREP OR PMG THE ALTERNATOR CONTROLS THE SITUATION DURING 10 SECONDS THE DEFFECT IS RELEASED THE BREAKER TRIPS - THE POWER SUPPLY IS MAINTAINED

SHUNT

SHUNT THE ALTERNATOR DOES NOT HOLD THE SITUATION DESENERGIZING OF THE ALTERNATOR - THE POWER SUPPLY IS CUTTEN Ersin ERDALI

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Brush and Ring Mechanism :

-+

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- + -+

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Alternator Windings Heater: • Humidity can be reduced isolation resistance on alternator windings. In that case heater have to insert the windings for protection. •Heaters are 54W-220V for Mecc Alte ECO 3-28-31-32-3438 series. Other heaters are 65W-220V for ECO 40-43-46 (Optional 50W-110V).

Heater

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Bearing :

•Bearing is provided to rotate coupled components of alternator mandrel (main rotor, excitation rotor, PMG rotor, rotating diodes, etc.) by stability. •All alternators in Aksa are single bearing.

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Fan and Airconditioning :

• Alternator windings warme up by and by which induce current inside (J=I2Rt). Warmed windings have to be cooled for efficiency. Fan is used for cooling system. • Cooling has to be realized for protection of alternator windings. Therefore don’t close up air intake and drop ball places.

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Thermic Protection Components :

• Thermic sensors use to protect the warmness of windings in alternator (and in electrical motors). •PTC thermistor uses in Mecc-Alte ECO 37 – 40 – 43 series alternator by standard.

Bimetal Contact PTC Thermistor PT100 Thermic Resistor

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RFI Suppressor :

• RFI (Radio Frequency Interference) is noise vibration in alternator windings because of magnetic field (>1 kHz). • Filter with condenser is used to reduce the noises. • Standards :

BS EN 50081-50082 VDE 0875 BS 1597 MIL 461

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Paralleling Transformer:

• Paralleling transformer is used for syncronous operation with other alternators and also with the mains. • This transformer gives for Mecc Alte Eco 40-43 series alternators. It’s optional for other alternators.

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Blok Diagram For Alternator With PMG :

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Alternator With PMG : Mandrel Main Rotor Main Stator Bearing Excitation Rotor Excitation Stator Rotating Diodes Plate and Varistor PMG Rotor and Stator Terminal Connections Voltage Regulator Stator Cables Reference Cables PMG Cables Excitation Cables Main Rotor Excitation Cables Fan and Air-condition

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Block Diagram For Alternator With Transformer :

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4. Technical Knowledges and Numeral Rules

Mains – Generator Voltages : • Mains in Turkey ; Phase - Neutral Phase - Phase Frequence

: 220 V AC

: 380 V AC

• For USA;

: 50 Hz

• During the generator (or transformer) voltage selection, It has to be rate of 5% voltage difference between operating voltage (380 V AC) and generator nominal voltage (400 V AC). For our generators ; Phase - Neutral Phase - Phase Frequence

F: 60 Hz

V : 480/270, 208/120, 240/120

•For India and South Africa ; F : 50 – 25 Hz

: 231 V AC

: 400 V AC

: 50 Hz

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Generator Operation Powers :

GENERATOR OPERATION POWERS ACCORDING TO ISO 8528-1 STANDARDS:  Operation On Standby Power  Operation On Prime Power  Operation On Continuous Power Ersin ERDALI

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Generator Operation Powers :  Standby Operation (Operation on limited time) :

• This genset operation is used variable loads at no mains. • Load Measure: 110% (1 hour rate of 10% over load per 12 hours). • Annual Operation Time : 500 hours • Application : working centerum, hotels, hospitals, housing estate, resting places, factories and other requested stand-by application places. Ersin ERDALI

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Generator Operation Powers :  Prime Operation

(Operation on unlimeted time) :

• On unlimited time, maximum power from generator for variable loads. • Load Measure: 90% • Annual Operation Time: Unlimited • Application: Industrial and commercial companies, devoloping companies , cogeneration applications, rental and marine gensets. Ersin ERDALI

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Generator Operation Powers : Continuous Operation :

• On unlimited time, continuous power via generator. • Load Measure: 80% • Annual Operation: Unlimited, continuous. • Application: Continuous base load, mains, cogeneration, parallel operation.

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Power Quality and Gauge :

•Acceptable values for harmonic distortions according to IEC 519-1992 standard;

For Voltage (V) : 3% THD (total harmonic distortion) For Current (I) : 5% THD (total harmonic distortion) •More than limited harmonic distortions will be effected big problems and sacrifices. Ersin ERDALI

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Alternator Lifetime :

 On normaly condition, alternator lifetime is approximately about 100.000 hours for continuous operation  But ; • • • • • • • •

Over current Unbalance loads Operation on low Cos (power factor) loads Over ambient temperature Harmonics (because of warmness) Less air-condition Operation on pulverulent places Humid places

will be effected shorter than normaly. Ersin ERDALI

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Efficiency Of Alternator :

Efficiency = Output power / Input Power = kWe / kWm

 Alternator Losts

 Iron lost (Hysterysis and Eddy current)  Copper lost (Because of windings)  Friction lost (ballbearing)

 Efficiency of alternator depends on current of load.  Efficiency of alternator depends on power factor of load.  Efficiency is increased if Cos will increase.  Efficiency is reduced if Cos will reduce.

 Efficiency of alternator is approximately about ;  For 500-1500 kVA  For 0-100 kVA

%90-97 %85-93

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Voltage Unbalance Rate:

 Voltage unbalance is rated the biggest of 3 phases output voltages of alternator (U,V,W) and average output voltage.

 For example; Output voltages of alternator are about 236, 229, 225 volts;

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Effecting Alternator Of Voltage Unbalance :

• Because of voltage unbalance, A small magnetic field is induced on alternator windings which is direct opposite main magnetic field. • Voltage unbalance effects to warm windings up.

Example Calculation : Temp. Boost = Nominal Temp x 1 + 2

Temp. Boost = 80C x 1+2

(2,61)2 100

(Voltage Unbalance)2 100

= 80C x 1,136

Temp. Boost = 90,9 C Ersin ERDALI

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4. Technical Knowledges and Numeral Rules Setting Voltage Unbalance With “STAB” Potentiometer : Genset Voltage

Unstable Critical Good Slow

No Load

Full Load

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Cos Values Of Electrical Loads :      

Electrical Heater Incandescent Lamp 3 Phases Motors Fluorescent Lamp Neon Lamp Welder Machine Ersin ERDALI

1 1 0,7-0,9 0,3-0,5 0,4-0,5 0,4-0,8 58

4. Technical Knowledges and Numeral Rules  The Power Triangle : There are 3 types of electrical powers :

Apparent Power (S, VA) True Power (P, W)

Reactive Power (Q, VAR)

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Electrical Power Formulas:  Apparent Power (S, kVA)

  

The inductor does not use any true power. However, to the generator, the inductor “appears” to be consuming power because there is an opposition to current (inductive reactance) and voltage drop across it. The generator power is apparently used by the inductor.The total power used by the inductor and resistor is called appropriately. Apparent Power. Apparent power is measured in Volt-Amperes (VA) to distinguish it from true power.Apparent power for an inductive circuit can be found by multiplying the total current by the applied voltage;

) A V Q (kVAr) (k S



P (kW)

S  3UI Ersin ERDALI

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Electrical Power Formulas:  True Power (P, kW)

Inductance and resistance characteristics are both present in industrial motors which consist of many coils of wire. The coils cause current to lag voltage as in an inductor and because of coil length, the motor also has resistance. AC generator is used to provide power to a motor. The resistor is the only component that comsumes power. The power used by a resistor is called True Power.

) A V Q (kVAr) (k S



P (kW)

P  S  Cos  Ersin ERDALI

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Electrical Power Formulas:  Reactive Power (Q, kVAR)

 We know that reactive loads such as inductors and capacitors dissipate zero power, yet the fact that they drop voltage and draw current gives the deceptive impression that they actually do dissipate power. This “phantom power” is called reactive power, and it is measured in a unit called Volt-Amps-Reactive (VAR).

) A Q (kVAr) (kV S



P (kW)

Q  S  Sin  Ersin ERDALI

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Example Calculation For Electrical Powers - 1 :

 We will calculate full load current for 100 kVA gen-set at Cos=0,8 and Cos=1 ;

Q (kVAr) S



) A V k (

S  100kVA

S  3 U  I P  S  Cos

P (kW) Ersin ERDALI

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Example Calculation For Electrical Powers - 2 :

 Firstly we should calculate active power output of gen-set (Cos=0,8 for gen-set and it’s constant).  Following that ;

P  S  Cos  P  100  0,8  P  80kW CosCos=0,8  0,8 için; For

P  3 U  I  Cos

P 80000 I I   I  144,5 Amper Ampere 3 U  Cos 3  400 0,8 Ersin ERDALI

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4. Technical Knowledges and Numeral Rules Example Calculation For Electrical Powers - 3 :

P  80 kW idi..

 1 için; Cos ForCos  =1

P  3 U  I  Cos

P 80000 I I   I  115,6 Amper Ampere 3 U  Cos 3  4001

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Calculation For Pole Number :

NK Hz  120 Example :

 Hz : Frequence  N : Engine speed (rpm)  K : Pole number

We will calculate alternator pole number at 1500 rpm of engine speed.

NK 120 Hz Hz  K  120 N

120 50 poles K  K  4 Kutuplu 1500 Ersin ERDALI

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4. Technical Knowledges and Numeral Rules Suitable Generator Selection - 1 :

 A gen-set for 1000 kVA will supply a load for 900 kVA and Cos = 0,5 . We wiil calculate that; is it suitable power of generator or not? (For all gen-set; Cos = 0,8 constant).

 At the first we should calculate true power and reactive power both gen-set and load. Following that; For Gen-Set : Sgen = 1000 kVA

Cos ö = 0,8

For Load

Cos ö = 0,5

: Sload = 900 kVA

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 Suitable Generator Selection :

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Relation Between Voltage and Speed : • Alternator output voltage is rate of 75% at engine speed rate of 75%.

• Alternator output voltage is rate of 10% at engine low speed

• This graph is from MeccAlte alternator.

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Relation Between Voltage and Current :  No voltage reduction if no over load current (speed is fixed).

 Voltage is reducing on short circuit. Therefore short circuit open settings of thermic-magnetic circuit breaker should be according to 3ln.

• This graph is from MeccAlte alternator.

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Windings Connections For 12 Lead Alternators :

We use difference connections on alternator to provide difference voltages by easily. Accordingly possibility 115/200/230/400 Volts 50Hz on 12 lead alternators.



Series Star 

 

For 3 Phases Sysytems, 400 Vac (L-L), With neutral, 230 Vac (L-N)



Parallel Star   

For 3 Phases Sysytems, 200 Vac (L-L), With neutral, 115 Vac (L-N) Ersin ERDALI



Series Delta   

For 3 Phases Sysytems, 230 Vac (L-L), No neutral

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115 Vac (L(L-L)



346 Vac (L(L-L)

Parallel Delta 

 

For 3 Phases Sysytems, 115 Vac (L-L), No neutral,



3 Phases Zig-Zag    

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For 3 Phases Sysytems, 346 Vac (L-L), With neutral. Alternator output power multiple 0,866 (346/400) 73



230 Vac (L(L-L)

230 Vac (L(L-L)



Single Phase Parallel Zig-Zag    

For Single Phase Sysytems, 230 Vac (L-L), With neutral, Usually this connection uses in Europe’s countries.



Double Delta    

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For Single Phase Sysytems, 230 Vac (L-L), With neutral, Usually This connection uses in Asia’s and America’s countries. This is the same connection type of single phase parallel zig-zag. 74


Alternator Electrical Drawing : Excitation

+ Stator

Excitation Rotor

Uncontrolled 3 Phases Bridge Rectifier

VDC

AVR

-

VARÝSTOR

U V

W

+

Rotor

VDC -

Reference

Main

Main

Stator

U V

W

Points

170-250 V AC (PMG, AREP, Shunt) Voltage Regulator Supply

PMG

AREP

Stamford, Leroy-Somer Mecc Alte

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5. Protection Class (IP,H-F)

IP (Ingress Protection) Code:

 The International Protection code, sometimes called the Ingress Protection code, classifies the protection given by an enclosure against the touching of live parts, contact with moving parts and protection against the ingress of solid bodies.  It additionally specifies protection against the harmful ingress of liquids. Two (sometimes 3) digits are used to describe its protection rating, called the IP code. 

IP 2 3 C H     

IP 2 3 C H

: : : : :

Ingress Protection 1. Number (0-6 or X) 2. Number (0-8 or X) Addition letter depends on request ( A,B,C,D) Finishing letter depends on request (H,M,S,W) Ersin ERDALI

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Protection Class According to DIN 40050 Norm:

1.Number Protection from solid object       

0 1 2 3 4 5 6

: : : : : : :

Non protected Protected against Protected against Protected against Protected against Dust protected Dust tight

solid solid solid solid

object object object object

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greater greater greater greater

than than than than

50 mm 12 mm 2,5 mm 1,0 mm

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2.Number

Protection from moisture         

0 1 2 3 4 5 6 7 8

: : : : : : : : :

Non protected Protected against Protected against Protected against Protected against Protected against Protected against Protected against Protected against

dripping water dripping water when tilted up to 15° spraying water splashing water water jets heavy seas effect of immersion submersion Ersin ERDALI

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3.Letter

Addition letter depends on request ( A,B,C,D) For Dangerous Places ;  A : With hand  B : With finger  C : With equipment  D : With wire protection to arrive

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4.Letter

Finishing letter depends on request (H,M,S,W)

For Dangerous Places ;  H: High voltage device  M: Testing against water input demaged when the moving parts act (exp: rotor)  S : Testing against water input demaged when the moving parts stop (exp: rotor)  W: Suitable to use on specified weather condition and addition protection features Ersin ERDALI

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5. Protection Class (IP,H-F) ISOLATION CLASS OF INSULATOR MATERIALS ACCORDING TO VDE 0530 STANDARD:

• CLASS H ISOLATION : Allowable temperature 180°C’dir. temperature 130°C)

• CLASS F ISOLATION :

maximum is about (Operation is about

Allowable temperature 155°C’dir.

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6. Troubleshooting Guide

Before The Maintenance :

 Before any cleaning, lubrication or maintenance operation, ensure that the genarator is stationary and disconnected from the power supply  The people in charge of the handling must always wear work gloves and safety shoes  Do not operate the generator with protective covers, access covers or terminal box covers removed.  Disable engine starting circuits before carrying out maintenance Ersin ERDALI

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Alternator Maintenance :  Ballbearing Lifetime : • For the maintenance-free approximately 30.000 hours

ball

bearings

• For the lubricatable ballbearings approximately 40.000 hours

 Lubricating :

• Lubricating components should be cleanly. • Using the suitable oil. • Operate the alternator and shooting out the excess oil. Ersin ERDALI

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6. Troubleshooting Guide Checking The Windings :  Resistance Test

• According the alternator manual values; measuring and comparing windings resistance of the main stator-rotor and excitation statorrotor.

 Insulator Test

•Measure main stator-rotor and excitation stator-rotor with the meger (1MOhm).

• Before test remove all connections of the AVR. • During the test 500 V AC effect the windings. Ersin ERDALI

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6. Troubleshooting Guide Follow the suggestions below for troubleshooting : • Study the problem thoroughly before acting. • Refer to the alternator system diagrams. • Check the control unit and all cable connections • Do the easiest and most logical things first. • Find and correct the cause of the problem.

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Troubleshooting - 1 :

• Alternator does not excite ? Type of Troubleshooting

Solving the trouble

Faulty fuse

Substitute fuse

No permanent voltage

Shock the main rotor by polarity.

Low permanent voltage

Increase speed 15%.

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Troubleshooting - 2 : • Low voltage at no load ? Type of Troubleshooting

Solving the trouble

Voltage potentiometer is out of balance

Set the voltage potentiometer

Faulty windings

Check the windings

Regulator is protected

Check engine speed

Faulty regulator

Substitute the regulator

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• High voltage at no load ? Type of Troubleshooting

Solving the trouble

Faulty regulator

Substitute the regulator

Voltage potentiometer is out of balance

Set the voltage potentiometer

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• Normal voltage at no load, than lower voltage at loaded Type of Troubleshooting Regulator is protected Faulty regulator Faulty diodes

Solving the trouble

Current too high, power factor lower than 0.8, speed lower than 4% of rated speed. Substitute regulator Check diodes

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• Normal voltage at no load, than higher voltage at loaded Type of Troubleshooting Faulty Regulator

Solving the trouble

Substitute regulator

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Troubleshooting - 6 : • Unstable voltage ? Type of Troubleshooting Unbalance engine speed

Solving the trouble Set the engine speed

Faulty regulator

Substitute regulator

Stability potantiometer is out of unbalance

Regulate stability of regulator by acting on “STAB.” potentiometer.

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Troubleshooting - 7 : • Abnormal Noises ? Type of Troubleshooting Faulty ballbearings

Unstuck assembly

Solving the trouble

Substitute ballbearings

Check the assembly bolts. If it needs, substitute bolts

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ALTERNATOR TRAINING FINISHED

THANKS

QUESTIONS ANSWERS Ersin ERDALI

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Alternator Training

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