Sound Testing Procedure for the 795F AC XQ Off-Highway Truck {0116, 1000, 1801, 1806, 7000, 7076, 7261, 7329} Caterpillar

Off Highway Truck

795F (S/N: SNT1-UP)

Introduction

The purpose of this procedure is to provide the field with sound testing instructions for the 795F AC XQ Off-Highway Truck.

Refer to Operation and Maintenance Manual, SEBU8349 for machine preparation and operation, before performing the following tests.

Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.

Uphill Sound Test (Loaded)

Note: Measure sound levels using a 6 microphone hemisphere with an 18 m (59 ft) or 20 m (65.6 ft) radius based on ISO 6395:2008. Sound level recorded is truck sound power level (Lw) calculated from 6 microphone sound pressure levels.

Illustration 1	g06029421
Uphill sound test visual aid (AA) Minimum of 70 m (230 ft) from the front bumper to the microphones (A) Start (B) 35 m (115 ft) to 40 m (131 ft) from start (C) Maximum speed capable on grade (D) Sound hemisphere (E) 10 percent slope

1. Load the machine to 100 percent nominal capacity (A).

2. Park the machine facing uphill on a ramp with a 10 percent slope (E) and a minimum of 70 m (230 ft) (AA) from the front bumper to the sound hemisphere (D).

3. Warm the engine coolant to 82° C (180° F).

   Make uphill runs as needed to bring the coolant temperature to 82° C (180° F). Use Advisor to monitor the temperature during the runs.

4. Using Caterpillar Electronic Technician (Cat^® ET) set the engine fan speed to 420 RPM (A).

5. To test, accelerate to attain a speed of 11 km/h (7 mph) to 12 km/h (7.5 mph). Control the speed to 11 km/h (7 mph) to 12 km/h (7.5 mph) if the slope is less than 10 percent.

   Note: If travel speed is greater than 12 km/h (7.5 mph) entering the sound hemisphere, do not perform the test.

6. The machine will reach maximum speed capable on grade (for actual loading) around 35 m (115 ft) to 40 m (131 ft) (B) from start.

7. Ensure that engine fan speed and machine travel speed stabilizes (C). Record when passing through sound hemisphere (D).
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   Table 1

   Uphill Sound Test (Loaded)
   Machine Serial Number	Date	dB	Notes

Downhill Sound Test (Empty)

Note: Measure sound levels using a 6 microphone hemisphere with an 18 m (59 ft) or 20 m (65.6 ft) radius based on ISO 6395:2008. Sound level recorded is truck sound power level (Lw) calculated from 6 microphone sound pressure levels.

Illustration 2	g06029570
Downhill sound test visual aid (AA) Minimum of 70 m (230 ft) from the front bumper to the sound hemisphere (A) Start (B) Maximum machine travel speed 20 km/h (12.4 mph) (C) ARC engages (D) Grid fan transient starts (E) Entering the sound hemisphere (F) Sound hemisphere (G) 10 percent slope

1. Empty the machine to perform the downhill sound test.

2. Park the machine on a flat surface at the top of the hill (A).

3. Warm the engine coolant to 82° C (180° F) (A).
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   Illustration 3	g06030052

4. Set the ARC setting to 19.5 km/h (12 mph) to 20.5 km/h (12.7 mph). Set the FBR (Front Brake Retarding) switch to the ON position.

5. Using Caterpillar Electronic Technician (Cat^® ET) set the engine fan speed to 350 RPM (A).

6. Start the test, accelerating quickly to enter the down slope. Maintain truck speed to less than the ARC speed setting.

7. Release the throttle once the truck enters the slope to allow ARC to activate. ARC will not activate if the truck speed is greater than the ARC setting.

   Note: ARC engagement will occur after some travel on the slope.

8. A minimum of 70 m (230 ft) (AA) is required for ARC engagement (front of bumper) to the sound hemisphere (F).

   Note: A minimum of 12 seconds between ARC engagement and entering the sound hemisphere is required.

9. Ensure grid Fan speed transients start. Noise will be audible in the cab (D).

10. Enter sound hemisphere (E) at a steady travel speed (ARC controlled) (E).

11. Travel through sound hemisphere (E) while readings are taken. The Grid fan speed should be stabilized at this point.
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    Table 2

    Down Hill Sound Test (Empty)
    Machine Serial Number	Date	dB	Notes

Stationary Sound Tests

Note: Measure sound levels using a 6 microphone hemisphere with an 18 m (59 ft) or 20 m (65.6 ft) radius based on ISO 6395:2008. Sound level recorded is truck sound power level (Lw) calculated from 6 microphone sound pressure levels.

Stationary Sound Test on Ramp

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Illustration 4	g06035602
View of the stationary sound test on ramp

1. The stationary sound test must be performed on a ramp and a flat surface.

2. Place the machine in the center of the sound hemisphere.

3. Warm the engine coolant to 82° C (180° F).

4. Using Caterpillar Electronic Technician (Cat^® ET) set the engine fan speed to 420 RPM.

5. Allow 15 seconds to stabilize the fan speed, and start recording.
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   Table 3

   Stationary Sound Test on Ramp
   Machine Serial Number	Date	dB	Notes

Stationary Sound Test on a Flat Surface

Illustration 5	g06034090
View of the stationary sound test on flat surface

The stationary sound test must be performed on a flat surface.

Note: Obstructions must not be within 3 times the radius of the measurement hemisphere from the truck in all directions.

The truck must be placed in the center of the sound hemisphere.

1. Warm the engine coolant to 82° C (180° F).

2. Using Caterpillar Electronic Technician (Cat^® ET) set the engine fan speed to 420 RPM.

3. Allow 15 seconds to stabilize the fan speed, and start recording.
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   Table 4

   Stationary Sound Test on Flat Surface
   Machine Serial Number	Date	Ramp dB - Flat dB	Notes

Calculate Results

1. Calculate ramp sound corrections factor by subtracting sound levels in Table 4 from the results of Table 3 and report in Table 5. Correction factor(s) in Table 5 are then used to correct Static, Uphill Loaded, and Downhill Unloaded condition sound levels.
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   Table 5

   Sound Test on Ramp Minus Flat Surface Sound Test
   Machine Serial Number	Date	Ramp dB - Flat dB	Notes

2. Subtract ramp sound correction factor(s) in Table 5 from Uphill Loaded sound levels in Table 1 and report in Table 6.
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   Table 6

   Uphill Loaded Sound Test Minus Stationary Sound Test Delta (Stationary Flat)
   Machine Serial Number	Date	Uphill dB - Stationary dB	Notes

3. Subtract ramp sound correction factor(s) in Table 5 from Downhill Unloaded sound levels in Table 2 and report in Table 7.
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   Table 7

   Downhill Unloaded Sound Test Minus Stationary Sound Test Delta (Stationary Ramp - Stationary Flat)
   Machine Serial Number	Date	Downhill Unloaded dB - Stationary dB	Notes