Instructions for Inspecting, Insulating, and Repairing Stator Lead Cables on Certain Engines and Generator Sets{1408, 4459} Caterpillar

Electric Power Generation:

3516C GEN SET (S/N: SBK1-UP)

C175-16 GEN SET (S/N: WYB1-UP)

Engine:

3516B (S/N: PBR1-UP)

3516C (S/N: SBJ1-UP; SCK1-UP; SEK1-UP; SFK1-UP; SBM1-UP)

C175-16 (S/N: WYC1-UP)

C175-20 (S/N: BXR1-UP)

G3516H (S/N: GLM1-UP; GLN1-UP)

Generator Set:

CG170-16 (S/N: KSJ1-UP)

Introduction

The special instruction provides directions on how to inspect for abrasion of stator lead cables inside the generator, how to add protective provisions to prevent cable abrasion with 416-1646 Tape and/ or new cable supports, and how to repair cables with 475-0266 Repair Kit in the event the cables have been damaged due to abrasion.

This procedure is for low, medium, and high voltage generators (400V to 15,000V) of multiple lead wire configurations where stator lead cables may suffer abrasion due to repetitive movement against generator barrel window, other crossing cables, or cable supports. Testing has shown the solution to prevent abrasion is to effectively insulate cables and/ or to effectively hold the cable tightly in the cable support hole to prevent movement. This can be done by taping the leads or by using clamp style cable supports to ensure cables fit snugly in the holes. After periodic cable inspection, one or more of the following actions may be required:

• If no significant abrasion is observed, taping around cable is suggested.

• If significant abrasion is observed, cables will need repair prior to taping or upgrade to cable support.

Important Safety Information

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.

A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.

Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.

Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not specifically recommended by Caterpillar is used, ensure that it is safe for you and for other people to use.

Ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Caterpillar dealer for replacement manuals. Proper care is your responsibility.

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Personal injury or death can result from high voltage. When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present. Improper test equipment can fail and present a high voltage shock hazard to its user. Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made. When servicing or repairing electric power generation equipment: Make sure the unit is off-line (disconnected from utility and/or other generators power service), and either locked out or tagged DO NOT OPERATE. Remove all fuses. Make sure the generator engine is stopped. Make sure all batteries are disconnected. Make sure all capacitors are discharged. Failure to do so could result in personal injury or death. Make sure residual voltage in the rotor, stator and the generator is discharged.

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Personal injury or death can result from a spark. An incompletely discharged capacitor can cause a spark. Do not use the insulation tester in an explosive atmosphere.

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Personal injury or death can result from electrocution. The megohmmeter is applying a high voltage to the circuit. To avoid electrocution, do not touch the instrument leads without first discharging them. When finished testing also discharge the generator windings.

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Personal injury or death can result from the engine starting. Regardless of the cleaning method used; to avoid serious injury or death, make sure there is no voltage applied to the windings. Make sure the engine can not be started.

Parts Required

Illustration 1	g03782038

• If no lead abrasion is observed, add Scotch Electrical Splicing Tape #23 ( 416-1646 Tape ) around the cables for protection and to achieve a tight fit where the cables pass through the cable supports.

• If lead abrasion is observed, 475-0266 Repair Kit is suggested to repair cable and add taping around cable. If desired, clamping cable supports are available to be ordered separately.

- Silicon RTV

- Insulating Tape

- Heat Shrink Tubing

- Sand Paper

- Denatured Alcohol Wipes

- 8" x 8" x 0.12" neoprene mats (2)

Step 1 Inspection:

Generators are periodically inspected for cable abrasion. An action plan and parts can be ordered after determining the specific needs for each generator. The following inspection procedure must be followed:

1. Lock Out - Tag Out Engine - Generator from operation.

2. Remove Terminal Box cover.

3. Ground the Phase terminals to insure the winding are at ground potential. The location of the inspections is the area where the lead cables enter the terminal box though the lead board from generator and,

   1. If necessary remove incoming Load Leads from Terminals T1, T2, T3 to allow access to generator leads.

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Illustration 2	g03780719

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Illustration 3	g03780731

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Illustration 4	g03780764

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Illustration 5	g03782042

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Illustration 6	g03780738

4. Inspect all leads for lead cable damage. Refer to Illustration 2 and 3. Record the number of leads and the AWG size of the cables in case it is desired to install clamped cable supports. Also inspect where the leads exit the barrel of the generator by removing the access covers. Refer to Illustration 4, 5, and 6.

5. If significant damage to the cables is observed, lead cables may need to be replaced.

Step 2 Actions Required:

For cable leads with no damage, the procedure to eliminate the lead cable movement in the cable support as follows:

1. Lock Out - Tag Out Engine - Generator from operation.

2. Remove Terminal Box cover.

3. Ground the Phase terminals to insure the windings are at ground potential.

4. If necessary remove incoming Load Leads from Terminals T1, T2, T3 to allow access to generator leads and terminals.

5. Inspect all cable leads for damage and record.

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Illustration 7	g03782043

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Illustration 8	g03782044

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Illustration 9	g03782045

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Illustration 10	g03782046

6. If there is no damage to the lead cables, then add 416-1646 Tape so that the cable is held tight in the cable support. Wrap the tape tightly around the cable lead until the cable fits tight in the cable support hole. See examples of where lead cables can be protected with tape in the Illustration 11.

   1. For High Voltage units as shown in Illustration 7 remove the cable support bolts and lift the cable support up to tape the leads. One can also unbolt from the bus bar and push down to tape from the access hole. Refer to Illustration 9 and 10.

   2. For Medium Voltage units as shown in Illustration 8, remove the cable-ties and remove the cable support bolts to lift the lead board up. Tape the leads then pull the leads up through the cable support one at a time. Access through the access holes to adjust tape thickness if required.

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Illustration 11	g03782047

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Illustration 12	g03786317

7. For leads with abrasion damage, the procedure to repair is as follows:

   Repair Lead Cables as necessary with one of the following procedures.

   Note: Lead cable repairs may increase the diameter of the lead cable such that a larger hole is required in the cable support, or a clamp support may be required. Refer to Illustration 1.

   1. If the lead cable is damaged, but not beyond repair, make the repair as follows using the materials provided in the 475-0266 Repair Kit :

      (i) Sand the surface of the wire insulation in the repair area with a fine grit sandpaper, clean the area with denatured alcohol, and allow to dry.

      (ii) Insulate the wire as follows:

      - Cover the area with white RTV 162 silicone rubber adhesive sealant.

      - Cover the RTV with red silicone tapered tape. Use enough layers to build up to the original insulation height, and extend the final layer on to the lead cable insulation at least 1 inch.

      - Cover the silicone tape with heat shrinkable tubing. Refer to Illustration 13 for LV example and Illustration 14 for HV example.

   2. Re-bundle phase leads as necessary using cable ties.

   3. Reinstall all phase cable leads if they have been removed.

   4. Apply 1/8" thick neoprene rubber mat (from material kit), in areas where multiple lead cables run across a frame opening as shown in Illustration 12.

   5. Torque all terminal mounting bolts and lugs bolts to the proper value.

8. Perform Insulation Resistance (megger) test at 1000vdc to confirm insulation strength. Refer to the Special Instruction, SEHS9124, "Winding Insulation Maintenance and Cleaning and Drying of the Generators" for more information.

9. Take pictures of competed cable improvements for future reference.

10. Install terminal box cover.

Illustration 13	g03782121

Illustration 14	g03782122