Installation, Service & Maintenance Manual AC generators with the following for prefixes: UCI; UCM; UCD 224 & 274 .
SAFETY PRECAUTIONS Before operating the generating set, read the generating set operation manual and this generator manual and become familiar with it and the equipment. SAFE AND EFFICIENT OPERATION CAN ONLY BE ACHIEVED IF THE EQUIPMENT IS CORRECTLY OPERATED AND MAINTAINED. Many accidents occur because of failure to follow fundamental rules and precautions. ELECTRICAL SHOCK SEVERE PERSONAL DEATH. CAN CAUSE INJURY OR Observe all WARNING/CAUTION notices.
FOREWORD ELECTROMAGNETIC COMPATIBILITY Additional Information The function of this book is to provide the user of the Stamford generator with an understanding of the principles of operation, the criteria for which the generator has been designed, and the installation and maintenance procedures.
CONTENTS SAFETY PRECAUTIONS FOREWORD CONTENTS SECTION 1 1.1 1.2 1.3 1.4 SECTION 2 2.1 2.2 2.3 2.4 SECTION 3 SECTION 4 4.1 4.2 4.2.1 4.2.2 4.2.3 4.3 4.4 4.4.1 4.4.2 4.4.3 4.4.4 4.4.4.1 4.4.4.2 4.4.4.3 4.4.4.4 4.4.4.5 4.4.5 4.5 4.5.1 4.6 4.7 4.7.1 4.7.1.1 4.7.1.2 4.7.1.3 4.7.1.4 4.7.1.5 4.7.2 4.8 SECTION 5 5.1 5.2 5.3 5.4 5.
CONTENTS SECTION 6 6.1 6.2 6.2.1 6.2.1.1 6.2.2 6.3 6.4 6.4.1 6.5 6.5.1 6.6 SECTION 7 7.1 7.1.1 7.1.2 7.2 7.3 7.3.1 7.4 7.4.1 7.4.2 7.4.3 7.4.4 7.4.5 7.4.6 7.4.7 7.5 7.5.1 7.5.1.1 7.5.1.2 7.5.2 7.5.2.1 7.5.2.2 7.5.3 7.5.3.1 7.5.3.2 7.5.3.3 7.5.3.4 7.6 SECTION 8 8.1 8.
SECTION 1 INTRODUCTION 1.1 INTRODUCTION 1.4 RATING PLATE The UC22/27 range of generators is of brushless rotating field design, available up to 660V/50Hz (1500 rpm) or 60Hz (1800 rpm), and built to meet BS5000 Part 3 and international standards. All the UC22/27 range are self-excited with excitation power derived from the main output windings, using either the SX460/SX440/SX421 AVR. The UC22 is also available with specific windings and a transformer controlled excitation system.
SECTION 2 PRINCIPLE OF OPERATION 2.1 SELF-EXCITED AVR CONTROLLED The PMG system provides a constant source of excitation power irrespective of main stator loading and provides high motor starting capability as well as immunity to waveform distortion on the main stator output created by non linear loads, e.g. thyristor controlled dc motor. The MX341 AVR senses average voltage on two phases ensuring close regulation.
SECTION 3 APPLICATION OF THE GENERATOR The generator is supplied as a component part for installation in a generating set. It is not, therefore, practicable to fit all the necessary warning/hazard labels during generator manufacture. The additional labels required are packaged with this Manual, together with a drawing identifying their locations. (See below).
In standby applications where the running time is limited and reduced life expectancy is accepted, higher levels than specified in BS5000 can be tolerated, up to a maximum of 18mm/sec. Two bearing generators open coupled require a substantial bedplate with engine/generator mounting pads to ensure a good base for accurate alignment. Close coupling of engine to generator can increase the overall rigidity of the set.
SECTION 4 INSTALLATION - PART 1 4.1 LIFTING Incorrect lifting or inadequate lifting capacity can result in severe personal injury or equipment damage. MINIMUM LIFTING CAPACITY REQUIRED IS 750Kg. Generator lifting lugs should NOT be used Warning ! for lifting the complete generator set. Two lifting lugs are provided for use with a shackle and pin type lifting aid. Chains of suitable length and lifting capacity must be used.
4.2.2 TWO BEARING GENERATORS A flexible coupling should be fitted and aligned in accordance with the coupling manufacturer's instruction. If a close coupling adaptor is used the alignment of machined faces must be checked by offering the generator up to the engine. Shim the generator feet if necessary. Ensure adaptor guards are fitted after generator/engine assembly is complete. Open coupled sets require a suitable guard, to be provided by the set builder.
4.4.2 DIRECTION OF ROTATION The generator is supplied to give a phase sequence of U V W with the generator running clockwise looking at the drive end (unless otherwise specified at the time of ordering). If the generator phase rotation has to be reversed after the generator has been despatched apply to factory for appropriate wiring diagrams. UCI224, UCI274, UCM224, UCM274 Machines are fitted with bi-directional fans and are suitable for running in either direction of rotation.
4.4.4.5 TYPE MX321 AVR 4.4.4.4 TYPE MX341 AVR The following 'jumper' connections on the AVR should be checked to ensure they are correctly set for the generating set application. The following 'jumper' connections on the AVR should be checked to ensure they are correctly set for the generating set application. Refer to Fig. 5 for location of setting links. Refer to Fig. 4 for location of setting links. Fig. 5 1. Frequency selection terminals 50Hz operation 60Hz operation LINK 2-3 LINK 1-3 2.
4.4.5 TRANSFORMER CONTROLLED EXCITATION SYSTEM (Series 5) voltage is reached. Refer to Fig. 6a, 6b, 6c, 6d or 6e for control potentiometer location. This control system is identified with the digit 5 as the last digit of the frame size quoted on the nameplate. Important ! The excitation control is factory set for the specific voltage shown on the nameplate and requires no adjustment. 4.
4.7 LOAD TESTING During testing it may be necessary to remove covers to adjust controls exposing 'live' terminals or components. Only personnel qualified to perform electrical service should carry out testing and/or adjustments. Refit all access Warning ! covers after adjustments are completed. 4.7.1 AVR CONTROLLED GENERATORS – AVR ADJUSTMENTS Refer to Fig. 6a, 6b, 6c, 6d or 6e for control potentiometer locations.
4.7.1.2 EXC TRIP (Excitation Trip) AVR Types MX341 and MX321 DIP AVR Types SX421, MX341 and MX321 An AVR supplied from a permanent magnet generator inherently delivers maximum excitation power on a line to line or line to neutral short circuit or large overload. In order to protect the generator windings the AVR incorporates an over excitation circuit which detects high excitation and removes it after a pre-determined time, i.e. 8-10 seconds.
4.7.1.5 RAMP AVR Type MX321 The RAMP potentiometer enables adjustment of the time taken for the generator's initial build up to normal rated voltage during each start and run up to speed. The potentiometer is factory set to give a ramp time of three seconds, which is considered to be suitable for most applications. This time can be reduced to one second by turning the pot. fully counter clockwise, and increased to eight seconds by turning the pot. fully clockwise. 4.7.
SECTION 5 INSTALLATION - PART 2 5.1 GENERAL The extent of site installation will depend upon the generating set build, e.g. if the generator is installed in a canopied set with integral switchboards and circuit breaker, on site installation will be limited to connecting up the site load to the generating set output terminals . In this case reference should be made to the generating set manufacturer's instruction book and any pertinent local regulations.
SECTION 6 ACCESSORIES Generator control accessories may be fitted, as an option, in the generator terminal box. If fitted at the time of supply, the wiring diagram(s) in the back of this book shows the connections. When the options are supplied separately, fitting instructions are provided with the accessory. It is important to recognise that : The following matrix indicates availability of accessories with the differing AVRs. and 1. 2. Note the SX460 is not suitable for operation with accessories.
Generally 5% droop at full load current zero p.f. is sufficient to ensure kVAr sharing. If the droop accessory has been supplied with the generator it will have been tested to ensure correct polarity and set to a nominal level of droop. The final level of droop will be set during generating set commissioning. Should the generator be required to be converted from standard droop to 'astatic' control, diagrams are available on request. The setting procedure is exactly the same as for DROOP. (Subsection 6.2.1.
6.4.1 RESETTING THE BREAKER In the event of operation of the circuit breaker, indicated by loss of generator output voltage, manual resetting is required. When in the "tripped" state the circuit breaker switch lever shows "OFF". To reset move the switch lever to the position showing "ON". When fitted in the generator, access to the breaker is gained by removal of the AVR access cover. Danger ! Terminals which are LIVE with the generating set running are exposed when the AVR access cover is removed.
Stop the generating set. Remove the link between terminals K1-K2 at the auxiliary terminal block and connect a 5A switch across the terminals K1-K2. Turn the "I/LIMIT" control potentiometer fully anticlockwise. Short circuit the stator winding with a bolted 3 phase short at the main terminals. An AC current clip-on ammeter is required to measure the winding lead current. With the switch across K1-K2 open start the generating set.
SECTION 7 SERVICE AND MAINTENANCE As part of routine maintenance procedures, periodic attention to winding condition (particularly when generators have been idle for a long period) and bearings is recommended. (Refer to subsections 7.1 and 7.2 respectively). Any temporarily reduction in IR values can be restored to expected values by following one of the drying out procedures. 7.1.
It is possible that simply running the gen set unexcited – AVR terminals K1 K2 open circuit - for a period of say 10 minutes will sufficiently dry the surface of the windings and raise the IR sufficiently, to greater than 1.0 MΩ , and so allow the unit to be put into service.
Blown Air Drying Remove the covers from all apertures to allow the escape of the water-laden air. During drying, air must be able to flow freely through the generator in order to carry off the moisture. Direct hot air from two electrical fan heaters of around 1 – 3 kW into the generator air inlet apertures. Ensure the heat source is at least 300mm away from the windings to avoid over heating and damage to the insulation. Rebuild the genset, replace all covers and re-commission as appropriate.
Ground V and W phase and megger U phase to ground Ground U and W phase and megger V phase to ground Ground U and V phase and megger W phase to ground If the minimum value of 1.0MΩ is not obtained, drying out must be continued and the test repeated.7.2 BEARINGS All bearings are supplied sealed for life and are, therefore, not regreasable. Important ! Important ! Important ! The life of a bearing in service is subject to the working conditions and the environment.
7.4.2 SX440 AVR - FAULT FINDING 1. No voltage build-up when starting set 2. 3. 4. Check link K1-K2 on auxiliary terminals. Check speed Check residual voltage. Refer to subsection 7.4.7. Follow Separate Excitation Test Procedure to check generator and AVR. Refer to subsection 7.5. Unstable voltage either on no-load or with load 1. 2. Check speed stability. Check stability setting. Refer to subsection 4.6. High voltage either on no-load or with load 1. 2. Check speed.
7.4.5 MX341 AVR - FAULT FINDING 1. No voltage build-up when starting set 2. 1. Loss of voltage when set runninig Generator voltage high followed by collapse Voltage unstable, either on no-load or with load Low voltage on-load Excessive voltage/speed dip on load switching Sluggish recovery on load switching Check link K1-K2 on auxiliary terminals Follow Separate Excitation Test Procedure to check machine and AVR. Refer to subsection 7.5. First stop and restart set.
7.4.7 RESIDUAL VOLTAGE CHECK This procedure is applicable to generators with either SX460 or SX440 or SX421 AVR. 7.5.1 GENERATOR WINDINGS, ROTATING DIODES and PERMANENT MAGNET GENERATOR (PMG) Important ! The resistances quoted apply to a standard winding. For generators having windings or voltages other than those specified refer to factory for details. Ensure all disconnected leads are isolated and free from earth. Important ! Incorrect speed setting will proportional error in voltage output.
UCD27J UCD27K Rectifier Diodes The diodes on the main rectifier assembly can be checked with a multimeter. The flexible leads connected to each diode should be disconnected at the terminal end, and the forward and reverse resistance checked. A healthy diode will indicate a very high resistance (infinity) in the reverse direction, and a low resistance in the forward direction.
3. Set the AVR clockwise. VOLTS control potentiometer fully 4. Connect a 12V, 1.0A DC supply to the exciter field leads X & XX (F1 & F2) with X (F1) to the positive. 5. Start the generating set and run at rated speed. 6. Check that the generator output voltage is within +/-10% of rated voltage. Voltages at AVR terminals 7-8 on SX460 AVR or P2-P3 on SX440 or SX421 AVR should be between 170 and 250 volts.
The bearing(s) are a press fit and can be removed from the shaft with 3 leg or 2 leg manual or hydraulic bearing pullers. 4. SINGLE BEARING ONLY : Before trying to pull off the bearing remove the small circlip retaining it. Now ensure that the rotor is positioned with a full pole face at the bottom centre line. This is to avoid damage to the bearing exciter, or rotor winding, by limiting the possible rotor downward movement to the air gap length.
Damaged or worn components must be replaced. Caution ! When major components have been replaced, ensure that all covers and guards are securely fitted, before the generator is put into service. 7.6 RETURNING TO SERVICE After rectification of any faults found, remove all test connections and reconnect all control system leads. Restart the set and adjust VOLTS control potentiometer on AVR controlled generators by slowly turning clockwise until rated voltage is obtained.
SECTION 8 SPARES AND AFTER SALES SERVICE 8.1 RECOMMENDED SPARES Service parts are conveniently packaged for easy identification. Genuine parts may be recognised by the Nupart name. We recommend the following for Service and Maintenance. In critical applications a set of these service spares should be held with the generator. AVR Controlled Generators 1. Diode Set (6 diodes with surge suppressor) 2. AVR SX440 AVR SX460 AVR SX421 AVR MX321 AVR MX341 3. Non drive end Bearing UC22 UC27 4.
PARTS LIST TYPICAL SINGLE BEARING GENERATOR Plate Ref. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Description Stator Rotor Exciter Rotor Exciter Stator N.D.E. Bracket Cover N.D.E. Bearing ‘O’ Ring N.D.E. Bearing N.D.E. Bearing Circlip N.D.E. D.E. Bracket/Engine Adaptor D.E. Screen Coupling Disc Couplimg Bolt Foot Frame Cover Bottom Frame Cover Top Air Inlet Cover Terminal Box Lid Endpanel D.E. Endpanel N.D.E.
Fig. 11.
PARTS LIST TYPICAL TWO BEARING GENERATOR Plate Ref. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 Description Stator Rotor Exciter Rotor Exciter Stator N.D.E. Bracket Cover N.D.E. Bearing ‘O’ Ring N.D.E. Bearing N.D.E. Bearing Wave Washer.D.E. D.E. Bracket D.E. Screen Bearing D.E. Foot Frame Cover Bottom Frame Cover Top Air Inlet Cover Terminal Box Lid Endpanel D.E. Endpanel N.D.E.
Fig. 12.
PARTS LIST TYPICAL TWO BEARING (SERIES 5) GENERATOR Plate Ref. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 Description Stator Rotor Exciter Rotor Exciter Stator N.D.E. Bracket Cover N.D.E. Bearing ‘O’ Ring N.D.E. Bearing N.D.E. Bearing Wave Washer N.D.E. D.E. Bracket D.E. Screen Bearing D.E. Foot Frame Cover Bottom Frame Cover Top Air Inlet Cover Terminal Box Lid Endpanel D.E. Endpanel N.D.E.
Fig. 13.
Fig. 14.
A.C. GENERATOR WARRANTY WARRANTY PERIOD A.C. Generators In respect of a.c. generators the Warranty Period is eighteen months from the date when the goods have been notified as ready for despatch by N.I. or twelve months from the date of first commissioning (whichever is the shorter period).
REGISTERED OFFICE AND ADDRESS: BARNACK ROAD STAMFORD LINCOLNSHIRE PE9 2NB ENGLAND Telephone: 44 (0) 1780 484000 Fax: 44 (0) 1780 484100 SUBSIDIARY COMPANIES 1. AUSTRALIA : NEWAGE ENGINEERS PTY. LIMITED PO Box 6027, Baulkham Hills Business Centre, Baulkham Hills NSW 2153. Telephone: Sydney (61) 2 9680 2299 Fax: (61) 2 9680 1545 2. CHINA: WUXI NEWAGE ALTERNATORS LIMITED Plot 49-A, Xiang Jiang Road Wuxi High - Technical Industrial Dev.
