12A1. General. This section contains trouble-shooting information and tests that can be made to help determine the causes of some of the troubles that may develop in the   log system. Each symptom of trouble is followed by a list of the possible causes and a list of the possible remedies to correct the trouble.
1. Log does not start when rodmeter is lowered while ship is underway. 1a. Valve positions incorrect.

1b. 2Y circuit open.

1c. Rodmeter, hose, or bellows piping clogged.

1d. Hose lines reversed.

1a. Set valves to operating position (Figure 11-5).

1b. Close 2Y switch. Check fuses and circuits.

1c. Blow out rodmeter and hose. (See Section 13B2.) Clean out bellows piping.

1d. Install hose correctly (Figure 10-2).

2. Log does not operate when main balance arm and contact arm are carefully moved to the right. 2a. Master transmitter is not energized.

2b. Log power motor is inoperative.

2c. Gearing is jammed.

2d. Bellows punctured, or broken.

2a. Close the 1Y, 2Y, and 3Y switches. Check fuses and circuits.

2b. Check wiring. Replace power motor. (See Sections 13G21 and 13G24.)

2c. Check for presence of foreign matter in gears. Manually turn power motor drive gear to note any binding of gears. Lubricate gears.

2d. Replace bellows. (See Sections 13D2, 13D3, 13D4, and 13D5.)

3. Speed and distance readings low or nonexistent. 3a. Valve positions incorrect.

3b. Rodmeter, hose, or bellows piping clogged.

3c. Hose lines reversed.

3d. Large bellows leaks.

3a. Set valves to operating position (Figure 11-4).

3b. Blow out rodmeter and hose. (See Section 13B2.) Clean out bellows piping.

3c. Install hose correctly.

3d. Replace bellows assembly as a unit. (See Sections 13D2, 13D3, 13D4, and 13D5.)


4. Speed and distance indications are sluggish when ship's speed changes. 4a. Clogged rodmeter, hose, bellows piping, or a clogged snubber.

4b. Contacts dirty.

4c. Gears binding.

4a. Clean out rodmeter, hose, bellows piping, and snubbers.

4b. Clean contacts. (See Section 13A1.)

4c. Clean, lubricate, and replace damaged gears.

5. Log components operate correctly but excessive error of speed and distance indications occurs at all speeds. 5a. Air in bellows.

5b. Clogged rodmeter.

5c. Bent rodmeter.

5d. Log improperly adjusted.

5e. Condition of hull has changed radically due to outboard installation of new equipment near rodmeter.

5a. Vent system. (See Section 11A5.)

5b. Blow out rodmeter. (See Section 13B2.)

5c. If possible, pull up rodmeter and examine for bent tip. Replace with spare rodmeter. (See Sections 13C1, 13C2, 13C3, and 13C4.)

5d. Check A1, A2, and B adjustments and record figures on adjustment diagram. (See Section 14A10.)

5e. Recalibrate log over measured mile course. (See Section 13B.)

6. No distance indication. 6a. Distance transmitter burned out.

6b. Distance circuit not energized.

6c. Gears jammed.

6d. Synchronous motor (constant speed motor) burned out, and disk not rotating.

6a. Replace distance transmitter. (See Section 13G11.)

6b. Energize 2Y circuit.

6c. Clean and lubricate gears. Replace damaged gears.

6d. Replace synchronous motor. (See Sections 13G16, 13G17, and 13G18.)

7. Speed pointer does not return to zero when rodmeter is housed, or when cocks are set to zero position. 7a. Contacts are dirty.

7b. Excessive air in bellows.

7c. C adjustment is set incorrectly.

7a. Clean contacts.

7b. Vent system. (See Section 11A5.)

7c. Set C adjustment. (See Section 13A4.)


8. Rodmeter cannot be raised with hoist. 8. Rodmeter is bent 8. Replace with spare rodmeter. Salvage bent one and straighten if possible. (See Section 13C.)
9. Rodmeter gland leaks excessively. 9. Packing gland loose or worn. 9. Tighten packing gland nuts. Repack if needed.
10. Hum in transmitters in master transmitter indicator. 10. Excessive hum is due to shorts in circuits to master transmitter indicator or speed and distance indicators; or to binding of gears, bearings, or distance counters. 10. Check circuits. Check load on repeaters.
11. Time check on distance indication disagrees with speed indication. 11a. Constant frequency not exactly 60 cycles.

11b. Slipping clutch does not operate properly.

11c. Tension spring holding follower against disk too tight or too loose.

11d. Dead reckoning tracer or dead reckoning analyzer may be upsetting system.

11e. Follower worn.

11a. Check operation of constant frequency supply.

11b. Adjust slipping clutch. (See Section 13G45.)

11c. Check spring tension. (See Section 13G48.)

11d. Time the counter with the dead reckoning tracer, and dead reckoning analyzer cut out of the system.

11e. Measure diameter of follower. Diameter should be 1.200 inch plus or minus 0.002 inch. If seriously worn, replace. (See Sections 13G37 and 13G38.)

12. Speed indication on one speed and distance indicator does not agree with another. 12. Repeater not set on electrical zero. 12. Set repeater on electrical zero. (See Section 13F30.)
13. Both speed indicators show same variation from master transmitter. 13. Transmitter not properly set in mounting plate. 13. Reset transmitter in mounting plate. (See Section 13G10.)
14. Speed indicators are out exactly 180 degrees. 14. The primary circuit of the self-synchronous repeaters is reversed. 14. Reset primary leads.


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