KATO_Tech_Man.pdf

Instruction Manual I n s t a l l a t i o n • O p e r a t i o n • M a i n t e n a n c e

Standard AC generator Single or two-bearing

Drive-end air discharge

Kato Engineering Inc.

P.O. Box 8447 Mankato, MN USA 56002-8447 Tel: 507-625-4011 Fax: 507-345-2798 Email: katoengineering@lsusa.com www.kato-eng.com

Publication 350-01001-00, 8/26/05

Table of Contents Introduction Foreword Safety instructions Ratings/description Construction and Operating Principles Stator Rotor Bearings Connection boxes Excitation system Optional PMG system Other options Installation Receiving inspection Unpacking and moving Location Base design Assemble to prime mover, alignment Two-bearing alignment Two-bearing close-coupled alignment Single-bearing alignment Foot defl ection Doweling Electrical connections Space heaters Inspection before startup Operation Initial startup: generators w/auto & manual control Initial startup: generators w/auto control only Restoring residual magnetism/fi eld fl ashing Continuous operation Idling Parallel operation

Note: Because of rapid changes in designs and processes and the variability of Kato Engineering’s products, information in this manual must not be regarded as binding and is subject to change without notice.

The image on the front cover is representa-tive only. Several variations are available within the range of generators covered within this manual.

Maintenance Schedules Maintenance procedures Visual inspection methods of windings Cleaning Insulation resistance tests at low voltage Dry out procedures Bearing lubrication Rectifi er tests Disassembly Overall disassembly Exciter armature and PMG removal Bearing removal Assembly Bearing installation Overall assembly Exciter armature and PMG installation Storage Troubleshooting Guide Appendices List of equipment required for installation and maintenance Main part location

Introduction

Foreword This manual contains instructions for installing, operating and maintaining Kato Engineering AC brushless revolving fi eld generators.

These generators are manufactured in many sizes and ratings and with various options.

Lubrication information, electrical connection drawings, dimensional drawings and parts listings for your model are contained in the manual package as supplementary information and are the specifi c source of information for making connections and ordering replacement parts.

Information about optional components of your generator may also be contained as a supplement.

Please read this manual in its entirety before unpacking, installing, and operating your generator.

Safety instructions In order to prevent injury or equipment damage, everyone involved in installation, operating and maintenance of the generator described in this manual must be qualifi ed and trained in the current safety standards that govern his or her work.

While “common-sense” prevention of injury or equipment damage cannot be completely defi ned by any manual (nor built into any piece of equipment), the following paragraphs defi ne warnings, cautions, and notes as they are used in this manual:

Warning: Warnings identify an installation, operating or maintenance procedure, practice, condition, or statement that, if not strictly followed, could result in death or serious injury to personnel.

Caution: Cautions identify an installation, operating or maintenance procedure, practice, condition, or statement that, if not strictly followed, could result in destruction of or damage to equipment or serious impairment of system operation.

Note: Notes highlight an installation, operating or maintenance procedure, condition, or statement and are essential or helpful but are not of known hazardous nature as indicated by warnings and cautions.

Ratings/description Nameplates, which are located on the side of the generator, include serial and model number as well as rating information and bearing and lubrication information.

Construction and Operating Principles Stator The stator consists of the supporting frame, core, and armature windings.

The stator core is made from laminations, thin sheets of electrical steel, which are stacked and held in place by steel endrings and support bars. The rings and bars are welded to or are part of the steel frame.

Base mounting plates are welded to the bottom of the frame. The base mounting plates allow the assembly to be mounted on the genset base.

The windings (coils) are constructed of layered and insulated copper wire. The coils are inserted in the core slots, connected together, and the entire assembly is vacuum-pressure impregnated with resin. Stator leads terminate in standard connection lug or strap terminals for ease of connection to the load.

Rotor The main rotor assembly is the revolving fi eld. It consists of windings in a core, which is in turn mounted on a steel shaft. The exciter armature assembly and optional permanent magnet generator (PMG) rotor are also mounted on the shaft as are the fan(s) and other optional accessories.

The core consists of laminations, thin sheets of electrical steel, which are stacked together. The core makes the salient poles (four, six, eight or 10).

With six or more poles, the poles are typically attached to a center hub.

The rotor windings consists of insulated magnet wire wound around each pole. V-blocks between each pole keep the rotor windings in place.

Damper windings consist of copper or aluminum rods that are inserted through each pole surface and are brazed to copper or aluminum damper end plates at each end of the lamination stack. The end plates are brazed to adjacent poles to form a continuous damper winding. The ends of the windings are supported with bars or aluminum pole shoes. The rotor either has resin applied during the winding process or is vacuum-pressure impregnated with resin.

The shaft is made from high-strength rolled or forged steel and machined to accommodate all the rotating generator components. Keyways in the shaft ensure precise positioning of the rotor, exciter armature, and optional PMG rotor as well as drive couplings. On the exciter side, the shaft has a slot or hole in its centerline for running the revolving fi eld leads to the rectifi er.

Bearings The generator may contain either one or two bearings. Bearings are typically ball or roller type and are either 1) heavy duty double shielded bearings, which are typically used on smaller generators and are greased for life or 2) regreaseable bearings, which contain fi ll and drain ports for easy lubrication. Sleeve bearings are optional on some designs. A supplementary instruction will be included in the manual package for sleeve bearings if they are applicable to this generator.

Connection boxes The main lead connection box houses the load lead terminals. In addition, the generator may have auxiliary connection boxes for connecting temperature detector outputs, space heater connectors, and sensing outputs.

Excitation system The excitation system consists of the exciter stator assembly and the exciter armature assembly:

The exciter stator assembly consists of windings in a core. The core is made from steel laminations that are stacked and welded together. The main exciter stator coils are placed in slots in the core and form alternate north and south poles. The entire assembly is either mounted to the end bracket or mounted in a frame, which is mounted to the end bracket. The stator is a stationary fi eld, which is powered by the voltage regulator.

The assembly consists of two subassemblies: the exciter armature and the rotating rectifi er. The exciter armature assembly contains steel laminations that are stacked and keyed on the shaft or on to a sleeve, which is keyed to the generator shaft. A three-phase winding is inserted into slots in the laminations. The coils are held in place by insulating wedges. The coil extensions are braced with tape. Output leads from the winding are connected to the rotating rectifi er assembly.

The rotating rectifi er is a three-phase full wave bridge rectifi er, converting the AC from the exciter armature to DC, which is transferred to the revolving fi eld windings. Two aluminum steel plates, each containing three rotating rectifi er diodes, are mounted on each side of an insulating hub to form the negative and positive terminals. The plates also act as heat sinks for the diodes.

Excitation system functional overview: Exciter fi eld control is established by the strength of the exciter fi eld current developed by the voltage regulator system. The DC voltage and current levels of the exciter fi eld signal from the voltage regulator varies depending upon the generator output voltage and the loading of the output lines (see Figure 1).

Optional PMG system The permanent magnet generator (PMG) system consists of the PMG stator and PMG rotor:

The PMG stator is a stationary armature and is located within the stator assembly that also contains the exciter stator or is a separate stator mounted next to the exciter stator. The PMG stator consists of steel laminations. The laminations are held in place by steel compression rings and are welded to the frame bars of the exciter-PMG frame. The PMG windings are placed in slots in the laminations. Insulating wedges are inserted at the top of each slot to hold the coils in position.

The PMG rotor consists of rectangular permanent magnets and cast pole tips secured to a steel hub with nonmagnetic stainless steel bolts. The PMG rotor is keyed to the shaft and secured with a nut and lock washer.

PMG system overview: The PMG system functions as a pilot exciter, providing power to the automatic voltage regulator power supply. The PMG is an AC generator that uses permanent magnets in the rotor instead of electromagnets to provide the magnetic fi eld (see Figure 1).

Other options Other options include, but are not limited to, space heaters, fi lters, and temperature sensing devices.

Figure 1: Overview of excitation system (with an optional PMG)

Output leads

Voltage regulator

Exciter stator (fi eld)

Main stator (armature)

Shaft Main rotor (DC)

Rectifi er Exciter armature (AC)

PMG stator (armature)

PMG rotor (fi eld)

Prime mover

Power input

Installation Receiving inspection Before accepting a shipment, examine the packaging for any sign of damage that might have occurred during transit. Report any damage to the transportation company and Kato Engineering.

Unpacking and moving If the generator is received during cold weather, reduce condensation on cold surfaces and failure due to wet windings by allowing the generator to reach room temperature before removing the protective packing.

Unpack the generator carefully to avoid scratching painted surfaces. Do not remove the protecting lubricant from the shaft end or drive plates.

Inspect for loosely mounted components and the presence of moisture.

Inspect to make certain foreign material, such as crating nails, loose bolts or packing material, which may have fallen into the machine during unpacking, is removed. If damage is noted, determine the extent of damage and immediately notify the transportation company claims offi ce and Kato Engineering. Be sure to give complete and accurate details when reporting damage.

Move the generator by attaching an overhead hoist to the eyebolts installed on the generator frame or by lifting the generator from underneath the skid with a forklift.

Single-bearing generators are shipped with the exciter rotor assembly removed from the shaft and a support mounted across the drive discs to support the rotor.

Location Install the generator in an area so it complies with all local and industrial regulations. Locate it in a clean, dry, well-vented area or area that is suitable for the generator enclosure. Make sure it is easily accessible for inspection and maintenance.

Protect generators operating intermittently in very damp locations with space heaters. Slowly warm generators placed in operation after being subjected to very low temperatures to prevent excessive condensation.

Check winding resistance before placing the generator in operation (see instructions below).

Base design The type of base to be used will depend upon the nature of the installation site. However, the generator base must be rigid, level, and free from vibration. Mounting holes must be larger than the fasteners to allow for alignment.

Warning: Be alert at all times when installing, operating and maintaining the generator. Avoid contact with the uninsulated metal parts of the generator. Most injuries occur from faulty ground connections on portable electrical equipment and failure to ground stationary equipment.

Test all portable devices frequently to prove that a solid electrical circuit exits from the metal frame though the grounding conductor, in the electrical cord, to the grounding contact in the attachment plug.

Do not use electrical equipment with frayed, burned or damaged cords. Always take extreme care when moving the generator.

Be careful to not strike objects or personnel.

Apply lifting force to structural points specifi cally provided for lifting. Do not use the enclosure lifting holes to lift the whole unit. Use lifting means adequate to the weight. Observe lifting notices attached to the generator. Failure to observe these instruction can result in injury and damage to the generator.

Caution: Do not attempt to transport a single-bearing generator without maintaining proper rotor support and with the exciter rotor assembly removed. Failure to observe this warning can result in equipment damage.

Caution: Blocking or restriction of normal air fl ow into or out of the generator may cause damage to the electrical windings.

Assemble to prime mover, alignment Follow either the two-bearing alignment (if your generator model has two bearings but no adapter to bolt to an engine fl ywheel housing), two-bearing close-coupled alignment (if your generator model has two bearings and an adapter for bolting to a fl ywheel housing), or single-bearing alignment (if your generator has one bearing and drive plates).

Consult the factory for belt or gear drive alignment).

Two-bearing alignment Follow the tolerances specifi ed by the coupling manufacturer when they are less than described in this manual.

Use shims, if necessary, between the mounting pad and the base to properly level and align the generator to the prime mover.

Install the coupling(s) on the generator and engine drive shafts in accordance with coupling manufacturer installation procedures. Use a straight edge and a thickness gauge for rough alignment as shown in Figure 2. Check for angular and parallel alignment as follows:

Figure 2: Rough alignment

Straight edge

Thickness gauge

Notes: Mounting of the indicators must allow complete rotation of the prime mover.

Use dial indicators that are rigid so indicator sag won’t be a factor. Using the shortest offset distance of the indicator bracket will reduce the effects of indicator droop or sag.

During alignment, you may also need to compensate for engine expansion due to heating. Generator expansion is generally not considered a factor.

If the genset is moved to a different location, check alignment before startup.

Caution: Do not pry on the generator fan.

Caution: Generators equipped with sleeve oil bearings must have oil added to the bearing prior to rotation. See the bearing manual.

Angular alignment: Fasten a dial indicator to one of the coupling halves, and scribe the position of the dial button on the face of the opposite coupling half as shown in Figure 3. Rotate both shafts simultaneously, keeping the fi nger or button on the indicator at the reference mark on the coupling hub. Note the reading on the indicator dial at each one quarter revolution.

A variation of readings at different positions will indicate how the machine needs to be adjusted to obtain a maximum misalignment of

0.001 inch for each inch of the coupling hub’s radius, total indicator runout. Place or remove slotted shims from under the front or rear engine or generator mounting pads and/or shift the front or back half of one component from side to side until the components are properly aligned.

Tighten the mounting bolts, and recheck alignment.

Parallel alignment: Fasten a dial indicator to one of the coupling halves, and scribe the position of the dial button on the top of the opposite coupling half as shown in Figure 4. Rotate both shafts simultaneously, keeping the fi nger or button on the indicator at the reference mark on the coupling hub. Note the reading on the indicator dial at each one quarter revolution. A variation of readings at different positions will indicate how the machine needs to be adjusted to obtain a maximum misalignment of

0.002 inch. Place or remove slotted shims from under all of the engine or generator mounting pads and/or shift one component from side to side until the components are properly aligned. Tighten the mounting bolts, and recheck alignment.

Dial indicator

Figure 3: Angular alignment

Dial indicator

Figure 4: Parallel alignment

Two-bearing close-coupled alignment Check the engine fl ywheel housing pilot’s radial and face runout by mounting a dial indicator and measuring the fl ywheel to the fl ywheel housing as shown in Figure 5. See Table 1 for maximum allowable runout.

SAE housing number

0.5

0.002 0.003 0.003 0.004 0.004 0.005 0.005 0.006 0.007

Allowable runout (TIR)

10.500 12.375 14.250 16.125 17.625 20.125 23.000 25.500 31.000

Housing inside dia.

Table 1: Maximum allowable fl ywheel housing runout (inches)

Figure 5: Flywheel housing check

Shaft

Flywheel

Flywheel housing Dial indicator pointer for radial runout

Dial indicator pointer for face runout

Notes: Mounting of the indicators must allow complete rotation of the prime mover.

Use dial indicators that are rigid so indicator sag won’t be a factor. Using the shortest offset distance of the indicator bracket will reduce the effects of indicator droop or sag.

During alignment, you may also need to compensate for engine expansion due to heating. Generator expansion is generally not considered a factor.

If the genset is moved to a different location, check alignment before startup.

Caution: Do not pry on the fan.

Caution: Generators equipped with sleeve oil bearings must have oil added to the bearing prior to rotation. See the bearing manual.

Figure 6: Flywheel check

Shaft

Flywheel

Flywheel housing

Dial indicator pointer for radial runout

Dial indicator pointer for face runout

Check the engine fl ywheel’s radial and face runout by mounting a dial indicator and measuring the fl ywheel housing to the fl ywheel as shown in Figure 6. See Table 2 for maximum allowable runout.

6.5 7.5

11.5

0.002 0.002 0.002 0.003 0.003 0.004 0.005 0.005 0.006 0.007

Pilot diameter

Allowable runout (TIR)

Table 2: Maximum allowable fl y-wheel runout (inches)

Figure 7: Generator adapter check

Shaft

Adapter Dial indicator pointer for radial runout

Dial indicator pointer for face runout

Figure 8: Generator coupling check

Shaft

Adapter

Dial indicator pointer for radial runout

Dial indicator pointer for face runout

Check the generator adapter’s radial and face runout by mounting a dial indicator on the generator shaft or coupling as shown in Figure 7.

The maximum radial and face runout on the generator adaptor must not exceed 0.010 inch.

Check the generator coupling’s radial and face runout by mounting a dial indicator to the generator adapter as shown in Figure 8. The maximum radial and face runout on the coupling must not exceed 0.003 inch.

Measure and record the engine crank shaft endplay and generator endplay. Set the engine endplay to the manufacturer’s recommended position for alignment. Verify the generator end-fl oat is set at a position of one half of the measured distance or at a position that will allow full thermal growth of the gen erator shaft when operated at rated temperatures.

Mount the generator on the skid, and move the generator to within 0.010 inch of the engine. Place two 0.010-inch shims in the horizontal (9 o’clock and 3 o’clock) positions between the generator adapter and the engine fl ywheel housing. Raising the rear, exciter end of the generator as necessary, place two 0.010-inch shims in the vertical (6 o’clock and 12 o’clock) positions between the generator adapter and the engine fl ywheel housing. This will give a good starting point for alignment. Remove the vertical shims at this time. (If necessary, mark holes to be drilled on the base, and remove the generator at this time.)

Shaft

Flywheel

Flywheel housing

Dial indicator pointer for radial runout

Dial indicator pointer for face runout

Figure 9: Engine coupling check

Install the portion of the coupling that fi ts into the engine fl ywheel following the manufacturer’s recommended procedures and in accor dance with engine manufacturer’s specifi cations. Check the coupling’s radial and face runout by mounting a dial indicator to the engine fl ywheel housing as shown in Figure 9. The maximum radial and face runout on the coupling must not exceed 0.004 inch.

Mount a dial indicator on the generator shaft or half coupling to the fl ywheel radial surface for parallel alignment as shown in Figure 10.

Mount a dial indicator on the fl ywheel coupling to the face of the generator half coupling for angular alignment as shown in Figure 10.

Align the engine by rotating the prime mover in 90-degree incre ments and measuring total indicator runout. Tighten the generator to the base before taking each set of readings. Raise or lower the generator by adding or removing shims under the machined feet.

Shaft

Flywheel housing

Dial indicator pointer for angular alignment

Dial indicator pointer for parallel alignment

Flywheel

Figure 10: Alignment check

Following the fi nal generator adjustment and runout check, remove the horizontal shims from the adaptor fl ywheel housing, and move the generator all the way to the adaptor. Then tighten the fasteners. Recheck alignment. Make sure angularity (face) total indicated runout does not exceed 0.001 inch per inch of generator shaft diameter and parallel (radial) total indicated runout does not exceed 0.003 inch.

Torque the fasteners to the value shown in Table 3.

Note: Clearances between the adaptor pilot and the fl ywheel housing recess are designed to meet the tolerance of 0.001 to

0.015 inches.

Table 3: Recommended lubricated torque values. (If no lubricant is used, increase values by 25%.)

Grade 2

Size in-lbs. ft-lbs N-M

Min. Max. Min. Max. Min. Max.

4-40 3.3 4.7 0.4 0.5 6-32 6.1 8.7 0.7 1.0 8-32 12.5 17.8 1.0 1.5 1.4 2.0

10-32 20.8 29.7 1.7 2.5 2.3 3.4 1/4-20 50.4 72.0 4.2 6.0 5.7 8.1

5/16-18 92.4 132.0 7.7 11.0 10.4 14.9 3/8-16 159.6 228.0 13.3 19.0 18.0 25.8 7/16-14 252.0 360.0 21.3 30.0 28.9 40.7 1/2-13 378.0 540.0 31.5 45.0 42.7 61.0 9/16-12 46.2 66.0 62.6 89.5 5/8-11 65.1 93.0 88.3 126.1 3/4-10 105.0 150.0 142.4 203.4 7/8-9 141.4 202.0 191.7 273.9

Grade 8

Size in-lbs. ft-lbs N-M

Min. Max. Min. Max. Min. Max.

10-32 36 49 4.1 5.5 1/4-20 72 144 6 12 8.1 16.3

5/16-18 156 276 13 23 17.6 31.2 3/8-16 324 444 27 37 36.6 50.2

7/16-14 480 720 40 60 54.2 81.3 1/2-13 780 1020 65 85 88.1 115.2 9/16-12 1140 1500 95 125 128.3 169.5 5/8-11 1560 2040 130 170 176.8 230.5 3/4-10 2760 3600 230 300 311.8 406.7 7/8-9 4320 5760 660 480 488.1 650.8 1-8 6720 8640 560 720 759.3 976.2

Grade 5

Size in-lbs. ft-lbs N-M

Min. Max. Min. Max. Min. Max.

1/4-20 60 84 5 7 3.7 5.2

5/16-18 120 192 10 16 7.4 11.8 3/8-16 228 336 19 28 14 20.7 7/16-14 360 528 30 44 22.1 32.5 1/2-13 540 804 45 67 33.2 49.4 9/16-12 792 1152 66 96 48.7 70.8 5/8-11 1104 1608 92 134 67.9 98.8 3/4-10 2052 2724 171 227 126.1 167.4 7/8-9 3372 4368 281 364 207.2 268.5 1-8 5160 6432 430 536 317.1 395.3

Class 8.8

Size in-lbs. ft-lbs N-M

Min. Max. Min. Max. Min. Max.

M4 20 32 1.7 2.7 2.3 3.6 M6 65 113 5.4 9.4 7.3 12.8 M8 168 264 14 22 20 30

M10 324 516 27 43 38 58 M12 612 900 51 75 69 101 M14 960 1428 80 119 109 161 M16 126 184 170 250 M18 183 243 248 330 M20 263 341 357 463 M22 367 457 497 619 M24 465 580 631 787

Class 10.9

Size in-lbs. ft-lbs N-M

Min. Max. Min. Max. Min. Max.

M4 22 36 1.8 3 2.5 4.1 M6 77 122 6.4 10.2 8.7 13.8 M8 192 288 16 24 22 32 M10 384 576 32 48 43 66 M12 672 996 56 83 77 112 M14 1080 1554 90 132 122 179 M16 140 206 190 279 M18 205 271 277 368 M20 294 381 398 517 M22 409 510 554 691 M24 531 662 720 898

1-NM = 0.737 ft-lbs. = 8.85 in-lbs.

ASTM & SAE grade markings

Metric grade markings

Grade 2 Grade 5 Grade 8

Class 8.8 Class 10.9

Single-bearing alignment Before assembling the generator to the prime mover, remove the exciter cover and adapter cover. Remove the blocking holding the drive discs to the adapter. Also make sure the generator bearing end clearance is not less than the total engine crankshaft axial movement plus 1/16 inch. The generator is shipped from the factory with 1/8-inch minimum bearing end clearance. (This dimension is recorded on the Factory Recorded Dimensions sheet, packaged with the generator.)

Measure the distance from the end of the exciter shaft extension to the bearing housing on the endbracket (dimension A in Figure 11). This dimension is recorded on the Factory Recorded Dimensions sheet, packaged with the generator. If the dimensions do not match, move the rotor axially relative to the stator until the dimensions are equal.

Figure 11: Generator coupling check

Bearing

Endbracket

Exciter fi eld

Shaft extension

A

Notes: Mounting of the indicators must allow complete rotation of the prime mover.

Use dial indicators that are rigid so indicator sag won’t be a factor. Using the shortest offset distance of the indicator bracket will reduce the effects of indicator droop or sag.

During alignment, you may also need to compensate for engine expansion due to heating. Generator expansion is generally not considered a factor.

If the genset is moved to a different location, check alignment before startup.

Caution: Do not pry on the generator fan.

Caution: Generators equipped with sleeve oil bearings must have oil added to the bearing prior to rotation. See the bearing manual.

Figure 12: Single bearing generator drive plate and adaptor

Caution: Never grind the OD of drive discs or attempt to drill out the holes. If the dive discs do not fi t properly, use different discs or a different fl ywheel.

S

Y

W A

Adaptor

Bolt holes

Drive plates

Fan

Shaft

Check the engine fl ywheel housing pilots’s radial and face runout by mounting a dial indicator and measuring the fl ywheel to the fl ywheel housing as shown in Figure 5. See Table 1 for maximum allowable runout.

Check the engine fl ywheel’s radial and face runout by mounting a dial indicator and measuring the fl ywheel housing to the fl ywheel as shown in Figure 6. See Table 2 for maximum allowable runout.

Measure the generator drive plate diameter (dimension S of Figure 12) and fl ywheel bore diameter (dimension B of Figure 13). Drive plate diameter must not be greater than the fl ywheel bore diameter. Also check to make sure the hole centers match (dimension W of Figure 12 and dimension C of Figure 13).

Measure the axial distance from the surface on the generator adapter to the outside surface on the drive disc coupling plates (dimension Y in Figure 12). This dimension is recorded on the Factory Recorded Dimensions sheet, which was packaged with the generator. If the dimensions do not match, move the rotor axially relative to the stator until the dimensions are equal.

Figure 13: SAE fl ywheel and adapter

Caution: The number and thickness of drive discs are specifi ed for torque requirements. Do not remove drive discs to compensate for spacing.

BC

G

Tapped bolt holes

Flywheel

Figure 14: Disc-to-fl ywheel installation

Flywheel

Drive plates

Drive hub

Spacer

Bolt

Lock washer

Measure the axial distance from the machined surface on the engine fl ywheel housing the bottom of the fl ywheel drive disc recess (dimension G in Figure 13). Make sure the difference between dimensions Y (of Figure 12) and G are less than 1/32 inch. If G is more than Y, install additional spacers between the drive discs and the generator hub. If Y is more than G, remove spacers between the drive discs and generator hub.

Install the generator to the engine. Make sure the drive discs seat in the recess of the fl ywheel housing. Secure the generator to the engine (drive discs to fl ywheel, adapter to fl ywheel housing), and the base. Use lock washers on all bolts. Torque the adapter and drive discs in a criss-cross pattern to the values in Table 3.

Ensure that the bolts in the fl ywheel do not bottom out. If they are too long or cannot be tightened with a socket or box wrench, use 1/4 to 3/8-inch long spacers inserted in the bolts as shown in Figure 14 to increase the clearance between the bolt head and the fl ywheel.

Occasionally, there is insuffi cient clearance to install the bolts that fasten the drive discs to the engine fl ywheel, and the fan will have to be temporarily moved to accommodate this. This situation will typically occur with several types of generators:

• With the three-frame units that have an aluminum fan, loosen the fan hub bolts to move the fan. After installing the drive disc-to-fl ywheel bolts, move the fan back so the rotor-side edge is fl ush with the air opening and the minimum distance between the windings and the fan is 3/8 inch. Torque the fan hub bolts to 75 ft-lbs.

• With sheet metal fans with cast hubs that are in turn mounted on the drive hub, mark the drive hub as closes as possible to the fan hub.

Loosen the two set screws, the fan clamping bolt, and the fan bolts.

Wedge the fan open, and move it out of the way (See Figure 15).

After attaching the drive discs-to-fl y wheel bolts, align the fan hub to the mark to move the fan back to its original position. Ensure the key is fully in place under the fan hub and positioned so the set screw will press on the key. Tighten the fan hub clamping bolt and the set screws. Install the fan bolts and torque them according to Table 3.

Note: The generator with sheet metal fans and cast fan hubs is shipped from the factory with the fan 1/2 to 3/4 inch from the fan baffl e and clear of the inside adaptor for optimum air fl ow through the exhaust screen.

Set screw

Key

Bolt holes

Alignment mark on drive hub

Fan hub bolt Fan hub

Keyway

Drive discs Fan

Fan bolts

Figure 15: Moving sheet metal fans

After installing the drive disc-to-fl ywheel bolts, check the runout of the generator shaft by placing the base of a dial indicator on the generator frame and positioning of the probe on the shaft as shown in Figure 16.

If the total indicated runout exceeds 0.003 inch, remove the drive discs bolts, and rotate the generator relative to the engine fl ywheel. Reinstall the bolts, and check the runout again.

Recheck the shaft-end-to-bearing-housing distance (dimension A in Figure 11).

Mount the brushless exciter armature assembly to the generator shaft (as described in the assembly procedures below).

Figure 16 Runout check

Drive plates

Dial indicator pointer

Drive hub

Shaft

Fan

Adapter

Foot defl ection After alignment, check for foot defl ection or “soft foot” condition on each shim location to eliminate distortion of the generator frame. Do this by loosing one mounting bolt at a time and checking defl ection after retightening. Defl ection at the shim location from shims under compression to a loosened condition must not exceed 0.003 inch.

Doweling In case the mounting bolts loosen during operation, doweling will prevent movement of the generator. Dowel as follows:

Check the alignment after the generator has been in operation for at least 48 hours. If alignment is not satisfactory, realign.

Drill holes through the footpads and into the base in two mounting pads opposite each other. Drill the holes slightly smaller than the dowel pin.

Ream the holes to the proper diameter for the pin. Clean out chips, and install the pins.

Electrical connections If the generator was subjected to a rapid change in temperature, freezing or wet conditions during shipment or storage, measure the insulation resistance of each winding and dry the generator, if necessary, as described in the maintenance section below.

Make all electrical connections (main load, temperature monitoring device, space heater, AVR) in accordance with local regulations and national/international electrical code requirements. Check the electrical diagrams provided with the generator or manual. The main terminals need to be properly spaced for the load connections. Refer to Table 3 for the proper torque values for the connections.

On larger generators grounding points are provided for properly grounding the system to the generator frame. The grounding wire must be sized to national/international code requirements.

Space heaters When the generator has optional space heaters to prevent water condensation during long periods of downtime, connect the space heaters so they start when the generator is turned off and stop when the generator is switched on. Refer to the electrical diagrams for the space heater characteristics.

Warning: The space heaters are designed to be energized when the generator is shut down. They are hot enough to cause skin burns. Terminals for power at the space heaters are live during operation.

Disconnect power to the space heaters before removing the generator covers.

Inspection before startup After electrical connections have been made, perform the following checks:

• Check all the connections to the electrical diagrams provided.

• Secure all covers and guards.

• Turn the rotor slowly with the appropriate starting mechanism (bar the engine or fl ywheel) through one revolution to see if the rotor turns freely.

• Check the bearings to see they are properly lubricated.

• Determine the direction of the engine rotation, and make sure that it matches the rotation of the generator.

• Make sure the power requirements comply with the data on the generator nameplate.

• Make sure that the engine-generator set is protected with an adequate engine governor and against excessive overspeed.

• Make sure the output of the generator is protected with an overload protection device, such as circuit breakers or fuses, sized in accordance with national/international electrical code and local electrical code standards. Fuses need to be sized using the lowest possible current rating above the full-load current rating (115% of rated current is commonly recommended).

• Remove tools and other items from the vicinity of the generator.

Caution: Do not pry on the fan.

Operation Initial startup: generators with both automatic and manual voltage control

1. Disconnect the generator output from the load by opening the main circuit breaker.

2. Turn the manual voltage adjust rheostat fully counterclockwise.

3. Put the auto-manual switch in the manual position.

4. Start the prime mover, and bring the set to rated speed. Turn the manual voltage adjust rheostat to reach rated voltage. Close the output circuit breaker, and apply load in steps until the rated load is reached. Adjust the manual adjust rheostat as necessary to obtain the desired output voltage.

5. Gradually reduce load, and adjust the rheostat accordingly until no load is reached. Open the circuit breaker, and stop the prime mover.

6. Actuate the auto voltage rheostat. Then start the genset, and bring it to rated speed. Adjust the voltage to the desired value.

7. Close the output circuit breaker. Then check the generator voltage and voltage regulation. Apply load in steps until the rated load is reached.

8. Check for vibration levels at no load and rated load. A slight increase is normal. As the load is maintained for 2-3 hours, the vibration levels will gradually increase and reach a fi nal level.

Initial startup: Generators with automatic voltage control only (generator has an automatic voltage regulator (AVR) with no auto-manual switch)

1. Disconnect the generator output from the load by opening the main circuit breaker.

2. Turn the voltage adjust rheostat fully counterclockwise. Start the prime mover, and bring the set to rated speed. Turn the voltage adjust rheostat to obtain the desired voltage.

3. Close the output circuit breaker, and apply load in gradual steps until the rated load is reach. Note the voltage regulation with the changes in load steps.

4. Check for vibration levels at no load and rated load. A slight increase is normal. As the load is maintained for 2-3 hours, the vibration levels will gradually increase and reach a fi nal level.

Caution: Do not actuate the auto-manual switch with the full load applied to the generator. Whenever possible, stop the generator before switching.

Restoring residual magnetism/fi eld fl ashing The direct current necessary to magnetize the revolving fi eld is obtained from the exciter. Upon starting the generator, current and voltage is induced into the exciter by the magnetic lines of force set up by residual magnetism of the exciter fi eld poles. Residual magnetism of the exciter fi eld poles may be lost or weakened by a momentary reversal of the fi eld connection, a strong neutralizing magnetic fi eld from any source, or non-operation for a long time. If the generator fails to generate voltage after it has come up to rated speed, it may be necessary to restore residual magnetism.

To restore the small amount of residual magnetism necessary to begin the voltage build up, connect a 12 or 24-volt battery to the exciter fi eld coil circuit and fl ash as follows:

1. Open the output circuit breaker, and stop the engine.

2. Disconnect the exciter fi eld coil wires EF1 at the terminal EF1 and EF2 at the terminal EF2, and connect the battery positive lead to the fi eld coil lead EF1.

3. Flash the fi eld by touching the battery lead to the fi eld coil circuit terminal EF2.

4. Disconnect the battery leads.

5. Reconnect the fi eld coil lead EF1 to terminal EF1, and reconnect the fi eld coil lead EF2 to terminal EF2.

6. Start the generator, and check for voltage build up. Refl ash if the generator output voltage does not build up, or fl ash with the generator running, the fi eld coil wires connected to the regulator, and a 3-amp or larger diode off the positive terminal of the battery per Figure 17.

Note: If the polarity of the exciter is reversed by fl ashing the fi eld, it may be corrected by interchanging the battery leads.

Figure 17: Field fl ashing setup with the fi eld wires connected to the regulator

12 or 24 V battery

3 amp or larger diode Voltage regulator F- F+

EF1EF2

Continuous operation Operate the generator within the nameplate values . If the generator is operated below the rated power factor and voltage, decrease the kVA to prevent overheating of the fi eld and stator windings. Consult the factory for derating factors if the application requires the unit to be operated beyond nameplate values.

Rotor overheating may occur when the generator is carrying excessive unbalanced loads. Negative sequence currents fl owing in the fi eld pole face cause the rotor heating. For a general guide to the allowable phase unbalance, see Figure 18, Guide to allowable phase unbalance (which is based on a 10% equivalent negative sequence current).

Figure 18: Guide to allowable phase unbalance

0 20 40 60 80 100

Max. current in any phase (% of rated)

M in

. c ur re nt in a ny p ha se o f r at ed

Excessive unbalance

Allowable unbalance

The guide is used in the following manner: Find the point where the vertical line (determined by the minimum current in any of the phases and expressed in percent of rated current) crosses the horizontal line (determined by the maximum current in any of the phases and expressed in percent of rated current). Ensure the point where these two lines intersect is within the permissible allowable unbalance region for safe operation of the generator.

Loss of fi eld excitation can result in the unit operating out of synchronization with the system when operating is parallel. This has the effect of producing high currents in the rotor, which will cause damage very quickly. Protective relays should be considered to open the circuit breaker.

Caution: Operating the unit beyond name-plate values may cause equipment damage or failure.

Idling Unless the voltage regulator has V/Hz protection built in, having the generator set in operating mode while idling the engine can cause permanent equipment damage. If engine adjustments require that the engine be run at idle speed and the regulator does not have V/Hz protection, make the generator regulating system inoperative during idling by one of the following methods:

When the generator is provided with a voltage shutdown switch, be sure the switch is set to the idle position while the engine is running at idle speed.

Where the generator set is provided with fi eld circuit breakers, set the circuit breaker to the off position while the generator is running at idle speed.

Where the generator set is provided with an automatic/manual control switch that has an off position, switch it to off while the engine is running at idle speed.

Where the generator set does not have any of the above options, remove the wires from the voltage regulator input power terminals when the engine is running at less than rated speed.

Parallel operation For the generator to operate in parallel with a system in operation, the phase sequence of the generator must be the same as that of the system.

Use transformers to reduce the voltage to an acceptable level, and then use a phase rotation meter or incandescent lamp method, described in electrical machinery handbooks, for a phase sequence check.

The output voltage at the paralleling point must be the same as each instant, which requires that the two voltages be of the same frequency, same magnitude, same rotation, and in coincidence with each other.

Voltmeters indicate whether the voltage magnitude is the same, and frequency meters indicate whether the frequencies are the same. Whether the voltages are in phase and exactly at the same frequency is indicated by a synchroscope or by synchronizing lamps.

A synchroscope can be used to indicate the difference in phase angle between the incoming machine and the system. The generator can be paralleled by using incandescent lamps connected as shown in Figure 19.

The voltage rating of the series lamps must equal the voltage rating of the transformer-low voltage winding.

Each prime mover in the system must have the same speed regulating characteristics, and the governors must be adjusted to give the same speed regulation as determined by applying load that is proportional to the full load rating of the generator.

Caution: Do not make connections or other-wise make contact with the generator leads or other devices connected to them unless the genset is stopped and the phase leads are grounded.

Caution: Refer to the voltage regulator manual for complete details and possible additional instructions. Damage to the rotat-ing diodes, generator, and voltage regulator can be caused if the regulator is operated improperly.

The voltage regulator must include paralleling circuitry. In addition, the voltage, droop settings and the V/Hz regulation characteristics must be the same for all the voltage regulators. This will allow the generators to properly share reactive loads.

If cross-current compensation is used, paralleling current transformers must give the same secondary current.

Current transformer secondary windings provide reactive kVA droop signal to the voltage regulator. Accidental reversal of this electrical wiring will cause the voltage to attempt to rise with load rather than droop. If this occurs during paralleling, stop the unit and reverse the wires at the voltage regulator terminals.

If the set is provided with a unit/parallel switch, set the switch to the parallel position on the unit being synchronized.

Synchronize the generator by adjusting the speed (frequency) slightly higher than the system. Observe the synchroscope or the lamps. The lamps should fl uctuate from bright to dark at the rate of one cycle every 2 to 3 seconds. When the generator is in phase (the lights will be dark), close the circuit breaker. Immediately after closing the breaker, measure the line current kVAR of the generator. The readings must be within the rating of the unit. A high ammeter reading accompanied by a large kW reading indicates faulty governor control. A high ammeter reading accompanied by a large kVAR unbalance indicates problems with the voltage regulator. Adjusting the cross current or voltage droop rheostat should improve the sharing of kVAR.

To shut down the generator operating in parallel, gradually reduce the kW load by using the governor to reduce speed. When kW load and line current approach 0, open the generator circuit breaker. Operate the generator unloaded for several minutes to dissipate the heat in the windings. Refer to the prime mover manual for shutdown and cool-down procedures.

Figure 19: Synchronizing paralleled generators with test lamps

Load lines from the incoming generator

Load switch

Synchronizing lamps

System bus

Maintenance Schedules A regular preventive maintenance schedule will ensure peak performance, minimize breakdowns and maximize generator life. The schedule listed below is a guide for operating under standard conditions.

Specifi c operating conditions may require reduced or increased maintenance intervals. Also, if there is a different or more specifi c schedule for your generator than the schedule provided below, it will be included as a supplement to the manual package.

Every day Visually check generator bearing housings for any sign of oil seepage.

Check the operating temperatures of the generator stator windings.

Check the control panel voltmeter for proper stability and voltage output.

Monitor the power factor and generator loading during operation.

With generators that have sleeve oil bearings, check the operating temperatures and sight glass levels (if applicable).

Every week Visually inspect the bearing exterior for dirt, and clean if necessary.

Inspect any generator air fi lters for build up of contaminants, and clean or replace as required

Every 2000 Hours or 6 months of operation Remove generator outlet box cover. Visually inspect the stator output leads and insulation for cracking or damage. Check all exposed electrical connections for tightness. Check transformers, fuses, capacitors, and lightning arrestors for loose mounting or physical damage. Check all lead wires and electrical connections for proper clearance and spacing.

Clean the inside of the outlet box, air screens, bearing housings, and air baffl es with compressed air and electrical solvent if needed.

With generators that have ball or roller bearings, check machine vibrations and bearing condition with a spectrum analyzer or shock pulse.

Regrease the regreaseable-type bearings. With generators that have sleeve oil bearings, inspect bearing oil for proper levels and clarity.

Warning: Do not service the generator or other electrical machinery without de-energizing and tagging the circuits as out of service. Dangerous voltages are present, which could cause serious or fatal shock.

Every 8000 hours or 1 year of operation Check insulation resistance to ground on all generator windings, including the main rotating assembly, the main stator assembly, the exciter fi eld and armature assemblies, and the optional PMG assembly.

Check the space heaters for proper operation.

Check the rotating rectifi er connection tightness.

With generators that have sleeve oil bearings, replace the bearing oil.

Every 20,000 hours or 3 years of operation With generators that have sleeve oil bearings, perform a sleeve bearing inspection to include the removal of the upper bearing housing and bearing liner to inspect the liner, shaft journal, and seal surfaces for wear or scoring.

Remove the endbrackets, and visually inspect the generator end windings for oil or dirt contamination. Excessive contamination may necessitate surface cleaning with compressed air and electrical solvent.

Inspect the fan and fan hub for damage.

Every 30,000 hours or 5 years of operation (Contact Kato Engineering for assistance)

Disassemble the generator (this includes rotor removal).

Clean the generator windings using either (depending upon the severity of contamination) 1) compressed air and electrical solvent or 2) de-greaser and high pressure hot water wash. Dry the windings to acceptable resistance levels (see the dry out procedure).

Inspect the rotor shaft bearing journals for wear or scoring.

With generators that have ball or roller bearings, replace the bearings.

With generators that have sleeve bearings, replace the bearing liners and oil seals.

Maintenance procedures

Visual inspection methods of windings Electric machines and their insulation systems are subjected to mechanical, electrical, thermal and environmental stresses that give rise to many deteriorating infl uences. The most signifi cant of these are the following:

Thermal aging: This is the normal service temperature deteriorating infl uence on insulation.

Over temperature: This is the unusually high temperature of operation caused by conditions such as overload, high ambient temperature, restricted ventilation, foreign materials deposited on windings, and winding faults.

Overvoltage: This is an abnormal voltage higher than the normal service voltage, such as caused by switching or lightning surges or non-linear loads. Operating above rated nameplate voltage will reduce insulation life.

Contamination: This deteriorates electrical insulation by 1) conducting current over insulated surfaces 2) by attacking the material to reduce electrical insulation quality or physical strength, or by 3) thermally insulating the material so the generator operates at higher than normal temperatures. Such contaminants include water or extreme humidity, oil or grease including unstable anti-wear and extreme pressure lubricants, conducting and non-conducting dusts and particles, industrial chemicals such as acids, solvents, and cleaning solutions.

Physical damage: This contributes to electrical insulation failure by opening leakage paths through the insulation. Physical damages can be caused by physical shock, vibration, over-speed, short-circuit forces or line starting, out-of-phase paralleling, erosion by foreign matter, damage by…