ENGGA Three-phase Synchronous Generators

Operation And Maintenance Manual

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General Safety Warning

EG Series generators are manufactured and incorporated with the latest design technology which enhances the

production process and strict quality control. Together with ENGGA patented technology on the Main Rotor and

Main Stator assembly have uplifted the product total reliability, quantity and superiority as a whole.

This manual contains information that is only suitable for use by qualified engineers and it is strongly recommended

that the User must read and fully understand this Operation and Maintenance Manual thoroughly. All subject related

to safety regulation and laws, technical standard, transportation method, installation, operation, maintenance and

repaired must be fully observed. The machines have dangerous part and when running, they have live and rotating

components. It must have adequate inspection and maintenance by qualified engineers to ensure no personal injury

or property damage.

Warning Leaflets

Warning labels are included when the machines are dispatched out from the factory and the assembler must ensure

that all the warning labels must be attached to the right position as recommended below.

Warning leaflets for an operation which may damage or destroy the machine or

surrounding equipment

Warning leaflets for general danger to personnel

Warning leaflets for electrical danger to personnel

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INDEX

1 INTRODUCTION

1.1 Standard

1.2 Name-plate description

1.3 Name-plate

1.4 Delivery inspection and storage

2 GENERATOR APPLICATION

2.1 Application

2.2 De-Rating table

3 GENERATOR PRINCIPLE

3.1 Operating principle

3.2 Main Stator

3.3 Main Rotor

3.4 Exciter

3.5 Automatic Voltage Regulator

4 INSTALLATION

4.1 Operating conditions

4.2 Installation

4.3 Rotation

4.4 Electrical connection

4.5 Protection

5 STARTING UP

5.1 Check before staring up

5.2 Commissioning

6 MAINTENANCE

6.1 General maintenance

6.2 Inspection and maintenance

6.3 Troubleshooting

6.4 AVR checking

7 STRUCTURAL DRAWING

8 PARTS LIST

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All the generator ratings are specified in the name-plate and if any abuses or not operating

according to the ratings conditions, the manufacturer shall not be held responsible should any damage occurred.

1 INTRODUCTION

1.1 Standard

ENGGA generators are designed in compliance to I.E.C 60034-1; BS 4999-5000; NEMA MG 1.22; C.S.A C22-2; VDE

0530 and GB755 standard; ISO9001:2000 certified and CE Marking and CCS approved.

1.2 Name-plate description

Example: EG280S—120N

EG - EG series generator 280 -Generator frame size (160; 225; 280; 315; 355; 400; 500)

S - Core length (M; L) 120 - Generator output in kW

N - designation of different version (N- latest 2007 series；H – marine application；B – non standard machines)

1.3 Name-plate

Name-plates are of special sticker type and shall be stick onto the right hand side of the generator drive end position.

1.4 Delivery inspection and storage

Customer shall open the wooden case immediately to check the generator’s name-plate, other documents and thoroughly

inspect all the machines to make sure everything is in proper order or any visible damaged to the machine after receiving it.

After that, if the generator is not to be installed at once, please pack it again and properly stored it in a dry and damp proof

place. The manufacturer shall not be held responsible for any damages which results from improper storage.

2 GENERATOR APPLICATION

2.1 Application

EG series generator rated output shall be installed and operated according to the following altitude and temperature.

a. Altitude height shall not over 1000m.a.s.l ;

b. Environment temperature shall be between -40ºC and 40 ºC respectively ;

c. Cool air relative humidity: ≤95%(25 ºC );

d. Generator shall be operated in a protected area and shall not be directly exposed to rain.

2.2 De-Rating table

Following de-rating table must be considered if the generator is operated in under below conditions

Altitude (m.a.s.l) Revise coefficient Temperature( ºC ) Revise coefficient

1500 0.96 45 0.96

2000 0.93 50 0.93

2500 0.90 55 0.90

3000 0.87 60 0.88

3500 0.85

4000 0.82

If generator application altitude and temperature are both above the standard, revise coefficient shall be calculated together.

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3 GENERATOR PRINCIPLE

3.1 Operation Principle

When the rotor being driven by the prime mover, a small magnetic field was set up and due to this, a small voltage is

induced. The AVR will sense this low voltage and compare it with the required voltage level. The AVR will find initially the

sensed voltage is considerably low than the required voltage. The AVR will provide such power from the main stator

winding to establish the exciter field. The exciter also have a small amount of residual magnetism.

The power from the main output winding (rectified by going through the AVR) will add to this residual level to produce a

greater magnetic field strength. With the exciter magnetic field strength increased, the a.c. output voltage from the exciter

rotor will also increase. This voltage is rectified by the rotating diodes. This extra excitation adds to the residual level of the

main field and produces an increase in output voltage from the main stator.

The AVR senses this increase and will further increase the excitation field excitation. The main stator voltage is building up

until the sensed voltage is the same as the required voltage.

Fig. 1 Operation Principle

A change in output due to load current is automatically compensated for by the AVR. This will adjust the excitation under all

circumstances in order to achieve minimum error between the sensed output voltage and the required voltage.

3.2 Main stator

The main stator frames are most ruggedly constructed with high strength and solid support. The frame is welded with heavy

rings and steel bars and reinforced with welding plates between bars. The main stator windings are the configuration of

triple-layer winding insulation type to ensure maximum insulation properties. All laminations of the stator core are

externally welded under pressure, to obtain the iron core. Ventilation ducts are provided along the stator core.

3.3 Main rotor

The main rotor is also the configuration of triple-layer winding protection type and the copper wires are of special made

rectangular type. The magnetic core of the main field is directly mounted on the shaft. The laminated rotor core reduces the

effect of superficial losses on the rotor. The rotor core at both end is incorporated with additional copper laminations and are

used as “end rings” for the copper squirrel cage. The rotor is then completed with the ammortisseur winding: it is composed

by several bare copper rods directly passing through the holes next to the surfaces of the poles. The rods are welded at both

ends to the additional copper laminations.

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3.4 Exciter

The exciter is considered as a small synchronous generator and its being installed at the non-drive end of the generator. All

the electrical power output produced by the exciter is rectify and used to establish the magnetic field of the main machine.

3.5 Automatic Voltage Regulator

The WT-2 Voltage Regulator is an encapsulated unit contained in a plastic case. The regulator controls the dc

exciter field power of conventional, 50 or 60 Hz brushless generators that have a max 63 Vdc exciter field to

regulate the generator output voltage. Regulation is provided by sensing the generator output voltage,

converting it to a dc signal and comparing the signal to a reference voltage signal. An error signal is developed

and used to control the dc field power in order to maintain a constant generator output.

Fig. 2 Connection of WT-2 in 200VAC system

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Fig. 3 Connection of WT-2 in 400VAC system

CONNECTION OF AVR

- the “J” is a connection for 50 Hz operation, or disconnection the “J” for 60 Hz operation.

- If an external voltage adjust control is being used, connect the potentiometer (minimum 1W, resistance

2000 Ω) to terminals Rv1 and Rv2. If not, connect a jumper between terminals Rv1 and Rv2.

- Connect the exciter field to terminals F+ and F-. Be sure to observe polarity.

- Connect the input power to the generator stator to provide power to terminals P1 and P4. The input should

be connected 200~277Vac.

- Connect the sensing input P2 and P4 for 400Vac operation or P3 and P4 for 200 Vac operation. The sensing

should be connected "line to line ".

PARALLEL OPERATION

When it is required to operate the regulator in parallel with an isolated or utility bus, in addition to the regulator

provisions, a 5 VA current transformer (CT) is required (See Figures 2 and 3.) This CT is connected in a generator

U line and should deliver from TP1 to TP2 amperes secondary current at rated load. The phase relationship of CT

signal to the regulator sensing voltage must be correct or the system will not parallel properly. The CT must be

installed in the U line of the three-phase generator. That does not supply sensing to the regulator.

Figures 2 and 3 show the correct CT polarity for A-B-C phase rotation sequence. If the phase rotation sequence is

A-C-B, the CT’s secondary leads must be interchanged.

ADJUSTMENTS

VOLT - potentiometer for adjusting the output voltage of the generator: to adjust the output voltage of the

generator: the voltage adjustment possibility depends on the characteristics of the generator. Normally the

internal potentiometer RP1 allows possibility of adjusting the voltage in a wide range (i.e. between 350 and 480 V,

or between 170 and 277 V); to obtain setting or to adjust the voltage from the control panel, or in order to limit

the voltage range, an external potentiometer can connected a finer possibility of voltage to the terminal “RV1”

and “RV2” (resistance about 2000 Ohm, 1W, to obtain +/- 5% voltage regulation).

⇒⇒⇒⇒ increase voltage

FREQ -potentiometer for changing the low speed protection: usually it is set at the factory in order to reduce the excitation when speed becomes lower than 90% of rated speed at 50 Hz. By removing the bridge which normally

shorts the terminals “Hz” and “60”, the speed protection acts properly for 60 Hz operation. By acting on

potentiometer RP3 it is possible to adjust further (in case should it be necessary) the frequency at which the low

speed protection is effective.

⇒⇒⇒⇒decrease frequency of intervention

STABILITY SETTING - The voltage regulator is provided with internal adjustable stability circuits in order to

allow operation in a wide range of applications. The operation of the regulator can be set on field to adapt it to

the characteristics of the plant and of the driving engine (i.e. diesel engine, water turbine, gas turbine) in order to

obtain the best voltage response. To change the stability characteristics of the regulator, it is necessary to act on

the potentiometer “RP2” for fine setting of stability

⇒⇒⇒⇒ increase response time, increase stability

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DROOP - The device is included in the voltage, to allow parallel operation between similar generators: the

device permits to share correctly the total reactive power required by the load among all generators operating in

parallel. The device is composed by an external current transformer (which is sensing the current in phase U) and

by a “droop” circuit internal in the regulator.

The voltage regulator is provided with input terminals (terminals “TP1” and “TP2”) for easy connection to

current transformer. Such terminals are normally short-circuited by a connection, when the generator is used in

single operation .If the voltage is increasing as the load increases, it is necessary to reverse the leads of the current

transformer at the terminals “TP1-TP2”.

Adjust the potentiometer “RP4” until the desired amount of droop is achieved

⇒⇒⇒⇒the droop increase

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During assembling of the generator, it is a must to ensure the machine is properly aligned.

Proper installation of the generator is of paramount importance to ensure a long lifespan of the

machine and shall be installed or assembled by highly qualified personnel only.

4 INSTALLATION

4.1 Operation Conditions

First of all, the operation conditions of the generator shall be identified before installation. The generator shall be operated

and installed in a clean environment, with good air flow and with ample of space for inspection, maintenance and routine

checking. The surrounding of the generator shall be free of atmospheric contaminations such as gasses and various

chemicals, salt water spray, dust and rainfall. It is also important to have a good airflow position, away from any hot or

exhaust system.

It is also recommended that if the generator were to install in an area with high condensation, a space heater shall be added

as an extra protection. If installed in an area of heavy laden of fine dust or sand, an inlet air filter shall be added on but due to

these, a certain output duration is required.

4.2 Installation

During assembling of the generator and the engine, it is important to have a solid and rigid base-frame to ensure no frame

deformation or frame twisting arises. We recommended to use Grade 8.8 bolt and nuts to assemble the generator set and to

also make sure the base-frame is sitting firmly to the ground surface. During installation, it is also important not to harm the

bearing and shall always keep the rotor assembly in alignment.

During the lifting of the generator, it is important to ensure the lifting slings or wire rope are in good condition and also

ensure the lifting block are able to sustain the generator weight. We recommended the lifting method shall be as per Figure 5

below.

Figure 5 Proper Lifting Method

It is not recommended to lift the generator using only 1 lifting hook and it is also not

recommended to use the generator lifting hook to lift the complete generator set.

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To ensure a proper generator set installation, it is important to have both the generator and the engine is properly alignment.

For both single or double bearing configuration generator, there is a SAE standard for the flange/adaptor and coupling disc

which is suitable for assembly with of Generator-Drive engine brands. Should the needs arise to use other non standard SAE

housing size, please kindly contact the manufacturer to confirm.

If the alignment of the generator to the engine is not in proper order, this could results in severe

personal injury, property damage or direct damage to the machine.

4.2.1 Single bearing generator installation

Assembling procedure are as follow :-

- initial checking of the engine housing and flywheel measurement is correct as per generator flange and coupling SAE

dimension supplied.

- dismantle the flange cover, position the generator in-line with the engine and then aligned the generator flange to the

engine housing. After that, align the generator coupling to the engine flywheel. This is to make sure all the surface is

vertically in-line with each other. Should it is not align, it can be adjusted by adding several shim to the baseframe.

- bolt the coupling disc to the flywheel housing using recommended number of bolts and size. We recommended to use

Grade 8.8 or above bolt type.

- it is recommended to turn the rotor to check there is no touching between the rotor and the stator assembly.

- after assembling the generator footing to the baseframe, the install back the flange cover.

4.2.2 Double bearing generator installation

Assembling procedure are as follow :-

- standard generators supplied are without special housing for connection between the generator to the engine housing

and can be available upon request..

- before installation, it is required to have a pre-balancing coupling/adaptor fit to the generator shaft end.

- position the generator in-line with the engine and then aligned the generator to the engine side. After that, align the

generator pre-balanced coupling to the engine flywheel. This is to make sure all the surface is vertically in-line with

each other.

- Should it is not align, it can be adjusted by adding several shim to the baseframe.

- it is recommended to turn the rotor to check there is no touching between the rotor and the stator assembly.

- after that, assemble the generator footing to the baseframe.

4.3 Rotation

Please ensure the generator rotating direction shall be the same as the label indicated direction. Generators are normally

supplied to operate correctly when rotating clockwise.

4.4 Electrical Connection

Before the cable connection, please ensure to have the right connection. This can be referred to the Connection Diagram base

on the specific voltage requested. The output cables have to be fixed to the terminal board as indicated in Figure 6.

Figure. 6 - Correct connection

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EG160~315 STAR CONNECTION VOLTAGE TERMINAL BOARD

L-L L - N

50Hz 380~415 219~240

60Hz 416~480 240~277

EG160~315 DELTA CONNECTION VOLTAGE TERMINAL BOARD

L-L L-N

50Hz 219~240

60Hz 240~277

EG160~315 STAR PARALLEL CONNECTION VOLTAGE TERMINAL BOARD

L-L L-N

50Hz 219~240 110~127

60Hz 240~277 110~138

EG160~315 DELTA PARALLEL CONNECTION VOLTAGE TERMINAL BOARD

L-L L-N

50Hz 219~240

60Hz 240~277

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EG160~315 DOUBLE DELTA CONNECTION VOLTAGE TERMINAL BOARD

L-L L-M

50Hz 220~240 110~120

60Hz 240~277 120~138

EG160~315 ZIG-ZAG CONNECTION VOLTAGE TERMINAL BOARD

L-L L-M

50Hz 208~240 110~120

60Hz 240~277 120~138

EG355~500 STAR CONNECTION VOLTAGE TERMINAL BOARD

L-L L-N

50Hz 380~415 219~240

60Hz 416~480 240~277

EG355~500 DELTA PARALLEL CONNECTION VOLTAGE TERMINAL BOARD

L-L L-N

50Hz 219~240

60Hz 240~277

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4.5 Protection

The generator supplied neutral cable is not connected to the frame. Should it is required, it can be connected. Inside the

terminal box, there is a earth terminal provided. There is a possibility during the complete generator set in operation,

over-speed, over-voltage, short-circuit and other possibilities can be occurred. Reliable protections are required. If running

on parallel operation, reverse power protection is also required.

During operation, it is required to follow strictly to the local regulations, laws and technical

Standards in force

5 STARTING UP

5.1 Check before staring up

After transportation, storage, installation and assembling of the complete machine, it is necessary to do a final check on all

the mechanical and electrical components before operation to ensure it is totally safe and properly protected.

5.1.1 Check the rotating rectifier set

It is required to test the diodes of the rotating rectifying set with a multi-meter. Prior to the testing, it is required to

disconnect all the connection cable of the diode. A good condition diode enables the current to flow only one direction, from

the anode to the cathode. Surge suppressor is a metal oxidation voltage-dependent resistance type and connected between

both incoming and outgoing cable of the main rotor. This surge suppressor is to protect the rotating diodes from damage

caused by high load changes or misuse.

5.1.2 Check the insulation

The generator has a very good insulation protection construction, unless it is being store for a long time or used in severe

climatic or atmospheric conditions, otherwise no other protection, for example heating is required. It is a good practice to

test the stator windings for ground insulation before starting the machine. If the ground resistance is below 2Mohm, then it is

necessary to dry the generator.

5.1.3 Check the earth connection

All the earth bolts in the generator support should be connected. Grounding has to be carried out using a copper wire of

suitable size, in compliance with applicable standards.

5.1.4 Check the connection

Standard generators are supplied with either 12 leads or 6 leads. The entry terminals cables in the terminal box is on the

right hand side. Terminals arrangement permits star series and star parallel connection. It is necessary when changing the

connection from star series to star parallel, to check and modify the connection to the AVR, according to the diagram

provided.

5.1.5 Check the final assembly

- check the engine and generator are properly alignment.

- check the inlet and outlet air passage is smooth and not being block by any big or large object or machinery. Also to

make sure there is no back pressure or hot air back circulation.

- check all the bolts are securely fastened and tighten and all protection are in proper.

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- check there is any dirt or dirty particles or waste inside the generator.

- check by turning the rotor to ensure again that there is no touching in between.

A word of final advice to ensure everything is in proper conditions, it is a must to check thoroughly the machine

based on above recommendation before start to operate.

5.2 Commissioning

All generators are fully tested at the factory prior to delivery. All generators are factory set at star series connection, 400V at

1500rpm.

5.2.1 No load adjustment

When the prime mover reaches the rated speed, the generator should have also reaches the rated voltage. If there is a different

in the voltage level, it can be corrected by adjusting the AVR. All three phase voltage should also be stable and balance.

5.2.2 Load adjustment

To ensure the generator is in good condition, applied the load by increasing and decreasing the load to check the voltage

stability level, check all the control panel metering is functioning in proper condition and also check on the generator of any

abnormal condition.

After the above steps, the generator is safe to operate. Please note that it is required to unplug the AVR when the prime

mover is running at low speed for a long time, otherwise, it will damaged the AVR and the excitation windings.

The generator have dangerous parts when operating they have live and rotating components.

Therefore improper use, disconnection of protection devices and not sufficient inspection and

maintenance can cause in personal injury or property damage.

6 MAINTENENACE

If there is a routine maintenance and checking program, the generator will function in good condition. It is important to

ensure safe and trouble free conditions throughout the operation period. It is recommended to follow every maintenance

measures highlighted in this manual.

When running hours of the generator achieved 500 running hours, it is recommended to check the insulations and clean the

stator and rotor assembly. When achieved 1000 running hours, it is recommended to check the temperature rise, fan

assembly and bolt sets. It is recommended to have a fix maintenance schedule

6.1 General maintenance

- Generator should always be kept dry. In order to keep out of the humidity, please cover with cloth if not in used.

- Generator must be free from metal leftovers, drops, dust, acid-base steam or other harmful gases.

- During operation, the ventilation must be sufficient. Please ensure all openings are free and not be block by any

machinery or panel. Do not put anything on top of the alternator for it is bad for ventilation and heat elimination. Please

don’t remove the top terminal box cover.

- Please check the generator load from time to time. The load current should not over the rated current of generator.

When the load power factor is low, the excitation current should not over the rated value mentioned on the nameplate.

When the 3 phase load is not balance, the biggest phase current of that phase should not over the rated current.

- Please note the temperature of alternator bearing. The bearing temperature rise should not over 55K in general.

- During operation, the generator shall not over the rated speed, voltage and ampere. Should abnormal smells, strange

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sound audible and excessive vibration detected, please stop the machine immediately and a thorough check up is required

before restart the machine.

6.2 Inspection and maintenance

- If the generator is not in use for some time, check the windings insulation. If it is lower than 2 Mohm, then it is

necessary to dry the generator and then repeat the test. If the grounding insulation still remains the same, then the

insulation has already aged and you should change the wire and insulation.

- Check the bearing and housing position to ensure there is no loose or wear and tear.

- check the airflow and internal condition. If inside the terminal box is too dusty, its required to be cleaned.

- check the alignment of the generator to the engine to make sure it is not out of alignment and also check the fan

assembly to ensure it is not deform.

- Check all cable connections especially the AVR side to make sure it is not loose.

All maintenance checking and servicing should be done after the machine is completely stop.

During maintenance, it is required to ensure all switches are turn to Off and also disconnect the

main power cables. To ensure safety, it is also recommended to place a Danger sign panel to keep

others well inform of any maintenance work on progress.

6.3 TROUBLE SHOOTING

Trouble Possible Cause Remedy Measures

No power supply Wrong connection

Rotating diodes damage

AVR connection loose

Short-circuit on main cables

Insufficient of residual voltage

Refer connection manual

Check in case of short-circuit and repair or change diodes.

Disconnect and reconnect all wire again.

Check and repair.

Apply 12V battery to recharge.

No load voltage

below rated

voltage

fuse blown

wrong connections of exciter

stator

Replace the fuse. If fuse blown again, check if the exciter stator

is short-circuit. Otherwise, change the AVR.

Check connection again

No load voltage

above rated

voltage

AVR setting problem

Adjust the AVR potentiometer (RP1)

Excitation current

too high

problem with diode Check, repair or replace the diode assembly

Vibration generator to engine not in-line

rotor balancing problem after

repair

bearing damage

engine problem

Check the alignment and rectify the problem.

Rebalancing required.

Check and change bearing immediately

Check and service the engine

Bearing heating operation exceed bearing

recommended running hours

insufficient of grease

generator to engine not in-line

Change bearing

Change bearing grease

Check the alignment and rectify the problem.

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Generator heating overloaded

power factor too low

rpm too low

airflow problem

Reduce to the rated load

Adjust the load and adjust the ampere to the rated level

Adjust the speed to the rated speed

Check the fan assembly and ensure not obstruction

Voltage unstable AVR problem Check, adjust or change a new AVR

6.4 AVR checking

To operationally test any WT-2 AVR, refer to Figure No.4 and perform the following steps:-

-Connect the voltage regulator as shown in Figure 4 and apply 230 Vac.

-Adjust the RP1 control fully counter-clockwise(CCW).

RESULT: Observe that the lamp does not light.

-Adjust RP1 control fully clockwise (CW).

RESULT: Observe that the lamp is now lit.

-Adjust RP1 control until the lamp just goes out.

AVR operation is satisfactory if the above results are obtained. Stability, however, must be tested with the generator and

AVR together.

Figure No.4 AVR wiring diagram

6.5.2 AVR troubleshooting

Trouble Possible Cause Remedy Measures

No power supply - insufficient of residual voltage

- RV1 and RV2 not connected，F+ and F- not

connected

- sensing cable not connected.

- generator set under-speed

- AVR damage

Apply 12V battery to recharge

Refer above diagram and re-connect

Reconnect again

Adjust to rated speed.

Change new AVR

Voltage too low - generator set under-speed

- wrong FREQ setting

Adjust to rated speed

Adjust the setting

Voltage too high - AVR setting too high

- AVR damage

Adjust AVR setting

Check and replace new AVR

Voltage unstable - RP2 wrong setting Adjust RP2

Voltage fluctuation

between 300V ～400V

- generator set speed too low

- wrong FREQ setting

Adjust generator set speed

Adjust the setting

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7 STRUCTURAL DRAWING

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Parts List

Items Qty Part Name Items Qty Part Name

1 1 Stator and Frame Assembly 29 7 Bolts M4X25

2 1 Rotor Assembly 31 1 Rotor Balance Ring

3 1 End Protection Cover 32 2 Bolts M4X40

4 1 Air Outlet Screen Protection 33 2 Bolts

5 1 End Shield 34 2 Bolts

6 1 Air Inlet Screen Protection 36 — Bolts

7 1 SAE Flange Adaptor 39 1 Key

8 2 Lifting Hook 40 1 Coupling Adaptor

9 1 AVR 41 1 Fan

10 1 Side Panel 43 1 Key

12 1 Back Panel 52 — Spacer

13 1 Terminal Box Cover 53 — Flexible Coupling

14 1 Front Panel 55 1 Exciter Rotor

15 1 Side Panel 57 — Bolt

17 4 Bolt M4X25 61 — Bolt

18 4 Bolt M4X25 62 1 Rotating Rectifier

20 1 Terminal Block 64 4 Bolt

22 1 Exciter Stator 68 1 Ring

23 7 Bolt M6 （8.8） 69 1 Ring

25 — Bolt 73 1 Bearing

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Important Notes

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Copyright by

ENGGA GENERATORS CO., LTD

http://www.engga.com.cn