BELT DRIVEN STATIONARY AGITATOR

Transcription

1 BELT DRIVEN STATIONARY AGITATOR INSTRUCTION MANUAL S. K Street Tulare, CA (559) (800) Fax (559) Revision Date 9/7/2017

2 TABLE OF CONTENTS How to Use this Manual... 1 Safety Instructions... 1 Qualifications... 1 Warnings and Symbols... 1 Description... 2 Installation... 3 Tools/Equipment Needed... 4 Motor, Pulleys, and Belt Installation... 4 Checking Rotation... 4 Installing in Pit... 4 Opening Oil Breather Line... 4 Checking Amp Draw... 4 Maintenance... 5 Tools Needed... 5 Scheduled Maintenance... 5 Top Bearing & Gearbox Seals... 5 Motor... 6 Pulleys and Belts... 6 General Maintenance... 6 Agitator Removal... 6 Inspection... 7 Disassembly of Agitator... 9 Replacement and Reinstallation Reinstallation of Agitator Spare Parts Troubleshooting Guide i

3 TABLE OF FIGURES Figure 1, Stationary agitator shown installed in pit... 2 Figure 2, Belt driven stationary agitator product features... 3 Figure 3, Grease zerk locations... 6 Figure 4, Disconnecting wires at the motor junction box... 7 Figure 5, Grease Bearings and U-Joint... 9 Figure 6, Propeller & Knife Figure 7, Removing gearbox Figure 8, Adjustable motor mount tensioning mechanism Figure 9, Pulley Removal Figure 10, Top Bearing Removal Figure 11, Splitting Yoke (Shown on Bench) Figure 12, Removing Flange Bearing (Old) Figure 13, Removing Flange Bearing (New) Figure 14, Drive Shaft & U-Joint Figure 15, Bottom end assembly ii

4 HOW TO USE THIS MANUAL The following instruction manual is to be used for the purposes of inspecting, installing and performing maintenance on US Farm System products. Each manual is specific to its product. Throughout this manual, pay attention to safety warnings and notes that will assist you in performing various maintenance tasks. Related documents and manuals are cross-referenced in this manual to provide additional relevant information. If you are reading an electronic copy of this manual, there are links embedded in the manual that you can use to navigate quickly between sections and other related documents. Read instructions carefully and follow the order of procedures mentioned in each section. Before performing any task in each section, review the required tooling list. The Scheduled Maintenance section explains the routines to follow to keep your product running well. The General Maintenance section explains more irregular maintenance and provides detailed instructions for disassembly and rebuild of product. At the end of the manual there is a Spare Parts section with recommended spare parts to keep onhand to maintain day-to-day operation of product. A Troubleshooting Guide is also provided for finding the cause of, and solutions to, common operational issues encountered with the product. SAFETY INSTRUCTIONS QUALIFICATIONS Persons installing or maintaining US Farm Systems equipment must be familiar with instructions listed in this document as well as have the skills required to perform such tasks. Make sure to reference the tools needed section within this manual to ensure that you can safely install or perform maintenance on equipment. Avoid potential hazards. Always abide by warnings and labels placed on products. If decals are worn or missing contact US Farm Systems for more information or replacements. WARNINGS AND SYMBOLS The following notes and warnings are used throughout this instruction manual to draw attention to important instructions: WARNING NOTE Special information on preventing injuries or requirements and prohibitions to prevent damage to the product. Special instructions to simplify working with the machine or to aid in efficient use of the product. 1

5 DESCRIPTION Figure 1, Stationary agitator shown installed in pit The U.S. Farm Systems Stationary Agitator is designed to agitate wastewater material from pits, preconditioning for transfer or mechanical separation. The propeller agitates material around it and breaks it up, making it ideal for separation or irrigation for fertilizer. Agitation typically begins prior to the manure separation system to help ensure optimum system performance. Belt driven agitators feature an easy to adjust motor mount. Pulley drive systems allow for the agitator to be run at various speeds to reduce wear and provide flexibility of function. Belt drive systems also help to protect your motor from damage if the pump driveline locks up during operation. 2

6 INSTALLATION Belt Guard Motor Lifting Bars Rotational Decal Universal Wall Mount Inspection Cover Bumper Knife Gearbox Propeller Feet Figure 2, Belt driven stationary agitator product features 3

7 TOOLS/EQUIPMENT NEEDED Amp tester Crane truck or other lift with chain hoist Welder Electrical tape Belt Tension Tester 1/2" concrete anchor bolts 15/16 socket (U-bolt) MOTOR, PULLEYS, AND BELT INSTALLATION Some agitators are shipped with the motor not installed on the motor base. If this is the case, then the motor, pulleys, and belts will need to be installed before placing the agitator into the pit. 1. To install motor onto motor base, lift motor with crane truck or chain hoist on forklift. 2. Line up motor bolt holes on motor and motor base with each other. Carefully lower motor onto the motor base and bolt in place once aligned. 3. Reference Belt Tensioning Manual for instructions on belt installation and pulley alignment. CHECKING ROTATION Always check rotation of motor when installing a new agitator for the first time or reinstalling an agitator after maintenance. Attach electrical wires to motor and panel per wiring diagrams inside motor junction box and electrical panel. Check the rotation of propeller before placing it in the water. When looking at the front of the propeller, the agitator must rotate clockwise. Agitator rotation is also indicated on the motor with a decal for reference. Also, reference Electric Equipment Installation Instructions. INSTALLING IN PIT Use a crane truck, or other similar lift with chain hoist, to attach to lifting bar of agitator (see Figure 2) lift and lower agitator into the pit. Make sure the feet on the agitator are resting on the bottom of the pit, the agitator is level, and the agitator bumper rests against the wall before anchoring the u-bolt agitator mount (Figure 2). As needed, reference Electric Pumps Brochure for installation dimensions of agitator. OPENING OIL BREATHER LINE On agitators and agitator pumps, opening the oil breather line will be necessary before running your machine. The breather line allows the oil that is inside the gearbox to expand and contract (heats up during operation and subsequent cooling), preventing pressure being put on the internal seals of the gearbox. The breather line is closed to keep oil from leaking during product shipment. It is marked on most products by a yellow tag and located at the top of the beam next to the motor. WARNING If not opened prior to putting the unit into operation, the gearbox seals will blow out and cause damage to the unit. CHECKING AMP DRAW After installing the agitator in the pit, you will want to check that agitator is running without pulling excess amps (running above motor specifications). Check the agitator motor amp draw as follows: 4

8 NOTE The more water the agitator moves, or the higher the viscosity of the liquid, the more amps the motor will draw. 1. Check the allowable amps on the placard on the motor. 2. Set-up amp meter and start the agitator. 3. If the amp readings are within the range specified, a qualified electrician should set the overload to 10% above usage to protect the motor. WARNING DO NOT run the motor if the amp readings are too high. The motor will be damaged and not covered under warranty. It may be necessary to change the propeller size or pulley ratio of agitator. It is recommended that you call US Farm Systems at MAINTENANCE The maintenance section is broken down into Scheduled Maintenance and General Maintenance subsections. Representing routine and infrequent maintenance items respectively. Always make sure the power is turned off, and proper lockout tagout procedures are followed, prior to performing any maintenance on the unit. NOTE Order all parts needed prior to starting maintenance. Reference Spare Parts section in this document. TOOLS NEEDED Saw horses, stands, or blocking to place agitator on, two or more needed Pipe Wrench C-Clamps Never-Seize Locktite 271 Cutting torch Crow Bar Grinder with Cutting Wheel Tape Measure Pry-bars or vice-grips Table jack Slide hammer SCHEDULED MAINTENANCE Scheduled maintenance pertains to the routine greasing and checkup of components maintain uninterrupted operation. Keeping up with maintenance will ensure equipment lasts longer and runs to specifications. WARNING Always turn off the power to an agitator before performing any maintenance. TOP BEARING & GEARBOX SEALS The top bearing needs to be routinely greased to prevent premature failure and damage to the top shaft of the agitator. See greasing instructions below: 5

9 1. See decals on agitator and reference US Farm Systems Lubrication Manual. 2. Grease the remote grease zerk at top of the agitator beam, this greases the top bearing (Figure 3). 3. Grease the remote grease zerks along the side of the beam that run down to gearbox, this greases and flushes the seals of the gearbox. Grease Zerks Figure 3, Grease zerk locations MOTOR The motor will also require routine maintenance. For motor maintenance instructions refer to the installed motor company s website for more information. PULLEYS AND BELTS Belts and pulleys are located under the belt guard. Routinely inspect the belts and pulleys for wear. 1. If there is noticeable vibration or noise coming from the belts or pulleys, or black dust from under the belt guard, there might be a problem with the pulley alignment or tension of the belts (also reference the Troubleshooting Guide). a. Re-tension the belts after one month of initial operation and check tension regularly at the same time other routine maintenance is performed. Refer to the Belt Tensioning Manual for more information. 2. Belts used on US Farm System pulley drive systems are v-belts. V-belts should stick out of the pulley sheaves about 1/8. If the belts are seated too deeply in the pulley sheaves, then the belts or the pulleys are worn and require replacement. a. Check the fitment of new belts in the old pulleys; if the new belts are still seated too deeply in the pulley sheaves, the pulleys will require replacement as well. 3. Refer to the Removing Pulleys & Belts section as needed. WARNING Always replace belts in matched sets to ensure the belts will perform as intended. GENERAL MAINTENANCE It is recommended to perform preventative maintenance on the agitator. You should routinely inspect the entire unit at 5000 operating hours. The following sections will explain how to inspect, disassemble, and reassemble the agitator. AGITATOR REMOVAL 6

10 You will need to remove the agitator from the pit prior to performing an inspection or maintenance. WARNING DEATH OR INJURY CAN OCCUR. High voltage may be available at the motor if the power supply is not properly disconnected. 1. Shut-off the circuit breaker or main switch that supplies power to the agitator motor. Figure 4, Disconnecting wires at the motor junction box 2. Wires can be disconnected at the main junction box or at the motor (Figure 4). If the wire run to the main box is not too long, disconnect at the main box. a. Clearly mark each of the three wires for reinstallation. Disconnecting at the motor junction box is possible but you will encounter more wires and it is frequently difficult to remove and reinstall the junction box cover. b. The propeller will push the agitator away from the pit wall if not wired correctly (see Checking Rotation). WARNING DEATH OR INJURY CAN OCCUR. Complete agitator assemblies weigh 1500 to 2500 lbs. They are also top heavy on the motor end. Lift with extreme caution. Make sure you have a lifting device capable of supporting at least 2500 lbs. 3. Removal from the pit. a. Attach chains around lifting bar on agitator assembly (Figure 2). Test that the chains are securely fastened. b. While lifting chains are tight, loosen and remove the u-bolts attaching the agitator to the agitator mounting assembly and pit wall. c. Remove from the pit and place across saw horses with the motor side down. Placing the agitator motor side down makes it less prone to accidentally flipping over. Make sure agitator is securely clamped down before proceeding. INSPECTION Maintenance always starts with removing the agitator from the pit and an inspection process to find potential sources of failures. This helps to ensure that any parts that require replacement are ordered from your dealer or US Farm Systems prior to performing maintenance. Refer to the following sections on how to inspect, perform installation, and maintenance different agitator components. Also, refer to the 7

11 Troubleshooting Guide at the end of this document for detailed instructions on causes of various malfunctions and their resolutions. Inspection of Propeller & Propeller Knife Generally, you should replace the entire bottom end assembly if replacement of the NOTE propeller or propeller knife is needed. Reference Removing Bottom End Assembly if necessary. The propeller agitates the wastewater and suspends solids for pumping. The propeller knife helps cut any twine or fibrous material that may tangle around the propeller. 1. Remove any twine or trash from between propeller and knife. 2. Inspect propeller for cracks, excessive wear, or bent blades, these are signs that the propeller should be replaced (reference Removing Propeller and Knife section). 3. If knife has excessive wear to area between propeller and knife so bolts protrude into propeller, replace knife. If dull, sharpen with grinder. Inspection of Gearbox Generally, you should replace the entire bottom end assembly if replacement of the gearbox is needed. Reference Removing Bottom End Assembly if necessary. NOTE Reference Gearbox Maintenance & Repair Manual for proper inspection instructions. Inspection of Top Bearing & Shaft The top bearing is attached to the top shaft of the agitator driveline. The top shaft is attached to a pulley that drives the agitator driveline and the top bearing stabilizes the top shaft. The top bearing can wear out over time due to the thrust generated by the pulley drive system, or an improperly installed set collar on the bearing can cause failure. If the bearing fails, the top shaft will likely be damaged and require replacement. 1. To inspect the top bearing, remove the pulleys and belts per the Removing Pulleys & Belts and the Removing Top Bearing & Shaft sections. 2. Inspect the bearing and top shaft. a. If there is any play with the shaft, bearing should be replaced. b. If the top bearing set collar came loose, shaft will be grooved and damaged and will require replacement. Inspection of Beam, Drive Shafts, and Mid Bearings You will want to do an inspection of the mid bearings of the agitator, inside the beam, and overall condition of the drive shafts inside the agitator beam assembly: 1. Remove the inspection cover(s) along the side of the beam. Check for any signs of moisture inside the beam. Moisture may indicate failure of bottom seals and can cause failure of bearings inside the beam. a. Moisture inside the beam is an indicator that there is a hole in the beam, an inspection port is not sealed properly, or the rubber seal between the gearbox and beam is worn and may require replacement. Refer to Removing Bottom End Assembly section as needed. 8

12 Grease Zerk Figure 5, Grease Bearings and U-Joint 2. Grease each bearing and u-joint per the US Farm Systems Lubrication Manual (Figure 5). 3. If the mid bearings or drive shafts are damaged or rusted and require replacement, refer to Removing Mid-Bearings & Drive Shaft and Mid-Bearings & Drive Shaft Reassembly in this document. NOTE DO NOT use paraffin based water proof grease. See US Farm Systems Lubrication Manual. Do not reinstall covers at this time. Inspection of Agitator Body Inspection of the overall condition of the agitator body includes examining the beam. 1. Inspect beam for excessive pitting or holes. Material wears and rusts thin over time and may require patching or replacement. 2. Cleaning and repainting the beam may be appropriate and will extend the life of the agitator. a. If the beam gets water or waste material inside, it can cause damage to the u-joints, drive shafts, and bearings. DISASSEMBLY OF AGITATOR If issues are observed during inspection, disassembly may be required to perform further maintenance or replacement. The following sections will give instructions of the disassembly of the different agitator components. Removing Propeller and Knife As you disassemble, always check propeller, knife and shaft for abnormal signs of wear. A worn, out-ofbalance propeller can destroy seals and bearings in just a few hours of operation. 1. Remove welds around reinforcement washer and remove center bolt (Figure 6). 2. Remove propeller and key by sliding off shaft or with slide hammer. 3. Remove side bolts on knife holder and fittings for grease line from gearbox. 4. Slide knife and knife holder off gearbox. 5. Remove weld between knife and knife holder. 9

13 Side Bolts Welded contact Center Bolt and Reinforcement Washer Figure 6, Propeller & Knife Removing Bottom End Assembly If the propeller and knife or gearbox need to be replaced, the entire bottom end assembly is generally replaced at the same time. To remove the bottom end assembly, follow these instructions: 1. Remove gear oil line and grease line from gearbox. 2. Remove bottom inspection cover from side of beam. 3. Set support, such as a table jack, under gearbox with clearance. 4. With propeller and knife holder removed, remove four bolts and welds on ends of angle on gearbox to beam mount (Figure 7). 5. Loosen gearbox shaft to u-joint. 6. Slide gearbox away from beam and out of u-joint. 10

14 Remove Welds Figure 7, Removing gearbox Removing Gearbox Components For detailed instructions on removing gearbox components, reference Gearbox Maintenance & Repair Manual. Removing Pulleys & Belts The pulleys on the motor and agitator shafts are both installed with taper lock bushings (Figure 9). If they need to be removed for replacement or to service the Top Bearing, proceed as follows: 1. Remove the belt guard. 2. Loosen the bolts on the adjustable motor mount tensioning mechanism (Figure 8). 11

15 Adjustable Tension Bolt Figure 8, Adjustable motor mount tensioning mechanism 3. Remove belts. 4. Remove the bolts in the taper lock bushing. 5. Remove bushings and pulleys as needed. Loosen each bolt one quarter turn at a time, until the bushing is free. A few light taps with a hammer may assist in removing bushing. Bolts Figure 9, Pulley Removal Removing Top Bearing & Shaft After removing belts and pulleys you may proceed with removing the top bearing and shaft: 1. Loosen bearing set collar. Reference Removing Mid-Bearings & Drive Shaft section for instructions on how to remove the two existing bearing styles. 2. Remove four retaining nuts and lock washers from bearing and slide off of the top shaft (shown in Figure 10). 12

16 Figure 10, Top Bearing Removal 3. If the top shaft needs to be removed, open the first inspection hole, at the top of the agitator beam. Loosen the set screw on the bottom portion of the u-joint that is welded to the top shaft, this is done through the top-most beam inspection port. Remove top shaft and u-joint through the top of the beam with the top bearing attached. NOTE In some cases, the u-joint slides easily off the bottom shaft. If this is not the case, pushing and prying on the yoke may help. If you beat on the shaft with a metal hammer, the flange bearing just below the u-joint will be damaged. 4. If the yoke will not come loose, try heating the yoke but try not to overheat the yoke bearings or the flanged mid bearing just below the yoke. If the u-joint will not release from the shaft, use a cutting torch to split the bottom yoke (Figure 11). Figure 11, Splitting Yoke (Shown on Bench) Removing Mid-Bearings & Drive Shaft If the flanged mid bearings require replacement or the drive shaft needs to be replaced, you will need to remove the mid bearings. 1. Make sure to clean the shaft before attempting to remove bearing. Loosen the set screw in the flange bearing eccentric lock collar and remove the collar. There are two variants of the bearing eccentric lock collar: 13

17 a. For models installed prior to 2016, rotate set collar opposite the direction of shaft rotation (Figure 12). Loosen the four retaining nuts on the flange bearing and remove the bearing by sliding it over the shaft. b. For models installed after 2016, loosen the screw in the set collar then slide it off (Figure 13). Loosen the four retaining nuts on the flange bearing and remove the bearing by sliding it over the shaft. Figure 12, Removing Flange Bearing (Old) Figure 13, Removing Flange Bearing (New) 14

18 NOTE Clean the shaft and remove burrs before attempting to remove bearing. If you beat on the bearing housing with a metal hammer, you will damage the bearing. In extreme cases, you may have to use a cutting torch to remove the bearing. 2. Go to the next lower inspection hole (if applicable) and repeat the same procedures. The bottom shaft slides through the bottom of the beam once the gearbox is removed. 3. Remove mid shafts (Figure 14) through the beam inspection holes as needed 4. Once all shafts and bearings are removed, check each for wear and damage. Questionable parts should be replaced. Figure 14, Drive Shaft & U-Joint REPLACEMENT AND REINSTALLATION Refer to the sections below to reassemble the agitator. Depending on the extent to which your agitator was disassembled, you will generally want to follow these sections in the order they are presented. Bottom End Assembly Reinstallation This section is applicable to replacing an entire bottom end assembly, or just reinstalling the gearbox to the beam. Follow instructions below: NOTE For instructions on reassembling gearbox components, reference Gearbox Maintenance & Repair Manual. 1. Install new gum rubber seal over spline shaft of gearbox. 2. Put gearbox on table jack or similar device and line up splined shaft on gearbox with splined yoke on bottom shaft. 3. Slide gearbox shaft through bottom of beam and into u-joint while insuring compression of seal between gearbox and beam. 4. Replace four bolts and nuts on gearbox mount angles (grade 8) and tighten (reference Figure 15). 5. Ensure seal compression. 6. Weld ends of mount angles together and tack weld bolts to angles on gearbox. 7. Replace gear oil line to gearbox and refill line with oil. 15

19 Bolts w/ Nuts Weld Figure 15, Bottom end assembly Propeller & Knife Reassembly If the entire bottom end assembly was not replaced and you just need to reassemble the propeller and propeller knife, follow instructions below: 1. Set knife holder in place with adjusting bolts loose. Adjustment can only be made within the distance between grease fitting and clearance hole. 2. Place knife on knife holder. Tighten four bolts securing knife to knife holder (reference Figure 6). 3. Replace grease line fitting. 4. Install propeller and clamp both sides of propeller to knife. 5. Install bolt and reinforcement washer. Weld reinforcement washer to propeller. 6. Release clamps from both sides of propeller and inspect propeller clearance. Propeller should just clear knife. The edges of the propeller and knife should shear by each other like a set of scissors. 7. Adjust knife to propeller clearance with adjustment bolts as needed, and then tighten adjustment bolts on both sides of knife holder. Mid-Bearings & Drive Shaft Reassembly 1. Reassemble in reverse order of steps in Removing Mid-Bearings & Drive Shaft section of this document. Old flange bearing lock collars rotate in the direction of shaft rotation when installing. Newer flange bearing lock collars require tightening of collar screw. Apply a liberal coating of Never Seize to all sliding parts and use Locktite 271 on all bolts. Once installed grease all bearings and u- joints. 2. Manually rotate the shaft to check for free movement. If the shaft turns freely continue. If shaft is hard to turn or has a hard spot, locate the source of this problem before completing assembly. 3. Install inspection covers with liberal coating of silicone seal if no other maintenance needs to be performed on the Top Bearing, Mid Bearings, or Driveshaft. Top Bearing & Shaft Reassembly To reinstall the top shaft and bearing, follow the steps in the Removing Top Bearing & Shaft section of this document in reverse order. Apply a liberal coating of Never Seize to all sliding parts and use Locktite 271 on all bolts. Once re-installed, grease all mid and top bearings and u-joints per US Farm Systems Lubrication Manual and install inspection covers with a liberal coating of silicone sealant. 16

20 Pulley & Belt Reassembly Make sure to refer to Belt Tensioning Manual. Install the bolts in the threaded holes in the top of the bushing. When reinstalling the bushing, tighten each bolt 1/4 turn at a time to the maximum torque listed below. Tighten these bolts until they just contact the bushing. Tap the face of the bushing with a metal hammer, then recheck torque. Type Bolt Size Torque (Ft Lbs) SH 1/4 9 SD 1/4 9 SK 5/16 15 SF 3/8 30 E 1/2 60 REINSTALLATION OF AGITATOR Make sure all maintenance and repair is performed before reinstalling agitator back into pit. WARNING Make sure power is off. 1. Place the agitator in the pit. Make sure the agitator legs are resting on the bottom of the pit and the bumper is against the wall. 2. Reattach the mounting u-bolts to the beam of the agitator. 3. If you labeled the wires prior to removal, make sure power is off and reconnect the wires. WARNING If the wiring is connected to the motor improperly, the motor may turn backward. This may damage the agitator. 4. Once all wiring is connected, run the agitator and check for unusual noise and vibration. 5. Once the agitator is moving water, check the amp draw on each leg of the wiring. The amp draw is only accurate if the agitator is moving water as it would under normal operation. If the amp draw exceeds the specifications listed on motor, do not continue to run the agitator. This will result in motor failure. Reference the Checking Amp Draw and Troubleshooting Guide sections of this document for detailed instructions. SPARE PARTS To maintain operation and maximize uptime of your product, it is recommended that you stock some spare parts for timely repair. The parts listed in the product parts book are recommended. Refer to the Stationary Agitator Parts Book supplied along with this manual. If applicable, always supply the product serial number, part number, or original invoice number when ordering parts. NOTE Serial Number required when ordering parts. 17

21 TROUBLESHOOTING GUIDE Fault Cause Solution When starting unit, propeller is rotating in wrong direction Belt driven units are vibrating noticeably, making noises around pulleys, or producing black dust Squeaking or grinding noise is coming from inside beam While unit is running, excessive noise is coming from top shaft Breaker keeps tripping Life of gearbox is less than 5000 hours Pulleys and belts of unit is spinning, but not agitating Electrical wires in motor j-box were installed incorrectly 1. Belts may not be correctly tensioned or are not from a matched set 2. Pulleys are out of alignment or worn excessively 3. Trash is stuck on the propeller and propeller knife Bearing is defective and requires replacement 1. Set collar of top bearing may be loose and causing damage to top shaft 2. Mid bearings may be damaged 1. Unit may have been incorrectly specified for its application 2. Trash is stuck on the propeller and propeller knife 3. Overload in control panel may be going bad 4. Low voltage, loose wire leads to motor or control panel Propeller may be out of balance or damaged The output shaft is broken inside the gearbox Switch two of the wires in the motor j-box, reference Checking Rotation section as needed 1. Adjust belts by referencing Motor, Pulleys, and Belt Installation 2. Reference Pulleys and Belts section of manual 3. Inspect propeller and knife for obstructions Replace bearing(s), reference Inspection of Beam, Drive Shafts, and Mid Bearings section Replace damaged shaft(s) and bearings as needed 1. Contact US Farm Systems to verify specifications 2. Inspect propeller and knife for obstructions 3. Contact electrician to inspect and replace overload 4. Check amps and voltage on wire leads connections Replace propeller and knife assembly Replace gearbox or bottom end assembly 18