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4
TROUBLE SHOOTING
 
A. TROUBLES, CAUSES AND REMEDIES
 
4A1. General. This section contains troubleshooting information and tests which will be helpful in determining the causes of some of the troubles that may develop in the log   system. Each trouble symptom is followed by a list of the possible causes of the trouble, and a list of the possible remedies to correct the trouble.
TROUBLECAUSEREMEDY
1. Log does not start when rodmeter is lowered while ship is underway. 1a. Valve positions incorrect.

1b. 2Y circuit open.

1c. Follow-up motor in rotary distance transmitter does not operate.

1d. Rodmeter, hose, control unit piping, or pump is clogged.

1e. Control unit or stop rods off adjustment.

1f. Hose lines reversed. Rodmeter reversed.

1g. Pump shaft is frozen tight.

1a. Set valves to operating position (Figure 3-4).

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

1c. Check wiring and limit switches. Replace motor. (See Sections 5G1 through 5G4.)

1d. Blow out rodmeter. Clean out hose, control unit piping, or pump.

1e. Reset contacts and stop rods. (See Sections 5K3, 5K4, 5K9, and 5K10.)

1f. Install hose correctly. Reverse rodmeter (Figures 2-1 and 2-4).

1g. Disassemble pump and make necessary repairs. (See Sections 5D3 through 5D27.)

2. Speed pointer indicates approximately 6 1/2 knots regardless of changes of ship's speed. 2a. Constant frequency supply (3Y) not reaching synchronous motor in master speed indicator.

2b. Starting condenser open or shorted.

2c. Synchronous motor stalled or burned out.

2a. Close 3Y switch. Check fuses and constant frequency supply switch. If constant frequency control unit is not running, throw switch to ship's a.c.

2b. Replace condenser.

2c. Attempt to start motor. Replace motor. (See Sections 5M26 and 5M31.)


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TROUBLECAUSEREMEDY
3. Speed pointer is sluggish, does not respond readily to changes of ship's speed. 3a. Clogged rodmeter hose, control unit piping, or pump.

3b. Control unit contacts dirty or off adjustment.

3c. Control unit contact arm rubbing on bearing plates.

3d. Bad leak in control unit bellows or gasket.

3e. Friction in bellows linkage, in shaft seals, or bearings of control unit.

3f. Sticky follow-up motor in rotary distance transmitter.

3g. Contacts in master speed indicator are dirty, burned, or too far apart.

3h. Friction in lead screw drive motor, or in lead screw gears.

3a. Blow out rodmeter. Clean out any other obstructions. (See Sections 5B1, 5B2, and 5B3.)

3b. Clean contacts. Readjust contacts and reset stop rods. (See Sections 5K1, 5K3, 5K4, 5K9, and 5K10.)

3c. Shift contact arm to provide clearance.

3d. Test and replace bellows and gasket. (See Sections 5K12 through 5K25.)

3e. Disassemble bellows housing, reduce friction in linkage or shaft assembly. (See Sections SK12 through 5K25.)

3f. Lubricate motor. Replace if necessary. (See Sections 5G1, 5G2, 5G3, and 5G4.)

3g. Clean and reset contacts. Clean brushes and slip rings. (See Sections 5M9, 5M14, 5M15 and 5M35.)

3h. Clean and lubricate motor, lead screw, and gears. Replace motor if necessary. (See Sections 5M4, 5M5, and 5M6.)

4. Speed pointer "hunts" over several knots on dial, especially at speeds below 10 knots. 4a. Pump seal too tight. (Shaft binds when ship is submerged.)

4b. Control unit contacts incorrectly set.

4c. Friction in jackshaft or follow-up gearing in master speed indicator.

4a. Disassemble pump. Change tension of seal bellows. (See Sections 5D3, 5D4, 5D9, and 5D27.)

4b. Reset control unit contacts. Reset stop rods. (See Sections 5K3, 5K4, 5K9, and 5K10.)

4c. Lubricate jackshaft and gearing.


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TROUBLECAUSEREMEDY
  4d. Friction in self-synchronous repeater or associated gearing in either master speed indicator or speed and distance indicator.

4e. Spiral take-up spring broken. Follow-up tension spring loose in master speed indicator.

4d. Clean and lubricate bearings of repeaters. Clean and lubricate connecting gears and bearings.

4e. Replace spiral spring. Tighten tension spring. (See Sections 5M10 and 5M33.)

5. Log components operate correctly but excessive error of speed and distance indications at all speeds is noted. 5a. Air in pump or control unit.

5b. Clogged rodmeter.

5c. Bent rodmeter.

5d. Pump orifice plug set incorrectly.

5e. Pump motor coupling slipping on shaft.

5a. Vent pump and control unit-on surface only. (See Section 3A3.)

5b. Blow out rodmeter. Clear hose pump, and control unit piping of obstructions. (See Sections 5B1, 5B2, and 5B3.)

5c. If possible, pull up rodmeter, examine for bent tip. Replace with spare. (See Sections 5C1 through 5C7.)

5d. Check setting of plug (Chapters 6 and 7).

5e. Tighten coupling and transmitter drive gears.

6. Log components operate correctly, but excessive speed and distance error below 10 knots is noted. 6a. Control unit contacts incorrectly set.

6b. Pump leaking excessively.

6a. Reset control unit contacts. Reset control unit stop rods. (See Sections 5K3, 5K4, 5K9, and ,5K10.)

6b. Repair pump seal. (See Section 5D11.)

7. Speed pointer does not return to zero when rodmeter is housed. Pump continues to operate. 7a. Control unit contacts dirty or off adjustment.

7b. Air in pump and control unit.

7c. Control unit contact arm rubbing on bearing plates.

7a. Clean and reset control unit contacts. Reset stop rods. (See Sections 5K1, 5K3, 5K4, 5K9, and 5K10.)

7b. Vent pump and control unit. (See Section 3A3.)

7c. Shift contact arm to provide clearance.


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  7d. Friction in bellows linkage, or in shaft seals and bearings of control unit.

7e. Sticky follow-up motor in rotary distance transmitter.

7d. Disassemble bellows housing. Reduce friction in linkage and shaft assembly. (See Sections 5K12 through 5K25.)

7e. Lubricate motor replace if necessary. (See Sections 5G1, 5G2, 5G3 and 5G4.)

8. Rodmeter cannot be raised with chain hoist. 8. Rodmeter is bent. 8. Replace with spare rodmeter. Salvage bent one and restraighten if possible. (See Sections 5C1 through 5C7.)
9. Rodmeter gland leaks excessively. 9. Packing Gland loose or worn. 9. Tighten packing gland nuts. Repack if needed.
10. Pump leaks at drip fitting, more than 3 drops per minute. 10. Pump seal assembly worn or corroded. 10. Disassemble pump. Repair or replace seal components. (See Sections 5D3 through 5D27.)
11. Pump is excessively noisy. 11a. Pump motor coupling incorrectly installed.

11b. Loose pump fan.

11c. Worn pump bearings.

11d. No clearance between end cap and pump housing.

11a. Check spacing of coupling halves. Check rubber block.

11b. Tighten fan. Replace if blades are broken.

11c. Disassemble pump, replace bearings. (See Sections 5D3, 5D4, 5D16 through 5D27.)

11d. Check end cap and spacers. Add shims if needed.

12. Noisy pump drive motor. 12a. Worn ball bearings.

12b. Slow speed shaft worm and gears worn.

12a. Replace ball bearings. Check armature end play. (See Sections 5D3, 5D4, 5D16 through 5D27.)

12b. Remove reduction gear housing. Clean or replace gear.


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TROUBLECAUSEREMEDY
13. Hum in transmitters in rotary distance transmitter. 13a. Excessive hum is due to shorts in circuits to master speed indicator or speed and distance indicator, or to binding of gears, bearings, or distance counters.

13b. Slight hum is due to excessive end play in transmitter shafts.

13a. Check circuits. Check load on repeaters.

13b. Add shims as required.

14. Control unit contact arm tends to rest on lower contact although rodmeter is housed and bypass valve is open. 14a. Air in control unit.

14b. Contact arm loose on contact arm shaft.

14c. Seal bellows stud not secured to primer bellows extension post.

14d. Stop rods too far apart, causing arm to shift under unequal pressures.

14e. Bellows has been stretched due to excessively unequal pressures.

14a. Vent control unit. (See Section 3A3.)

14b. Recenter and reclamp arm. Reset contacts and stop rods. (See Sections 5K2, 5K3, 5K4, 5K9, and 5K10.)

14c. Remove cover from bellows housing. Tighten capscrew. Recenter contact arm. Reset contacts and stop rods. (See Sections 5K2, 5K3, 5K4, 5K9, and 5K10.)

14d. Recenter contact arm. Reset contacts and stop rods. (See Sections 5K2, 5K3, 5K4, 5K9, and 5K10.)

14e. Recenter contact arm. Reset contacts and stop rods. Replace bellows if stretched too afar. (See Sections 5K2, 5K3, 5K4, 5K9, 5K10, and 5K18.)

15. Water appears at control unit cover over and above the quantity to be expected from sweating. 15a. Gaskets broken, eaten away, or misaligned.

15b. Punctured seal bellows.

15a. Remove housing cover and shaft seal bellows. (See Section 5K15.)

15b. Remove seal bellows and inspect. (See Sections 5K15 and 5K17.)


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TROUBLECAUSEREMEDY
16. Excessive friction in control unit contact arm. Arm does not return to exactly same spot when moved. 16a. Control unit contact arm rubbing on bearing plates.

16b. Contact arm shaft bearing corroded.

16a. Shift contact arm to provide clearance.

16b. Disassemble bellows housing. Replace bearings. Repair shaft seal assembly. (See Sections 5K13 through 5K25.)

17. Control unit stop rods cannot be set correctly. 17a. Threads stripped on rods.

17b. Rods do not contact bellows when in all the way. Bellows distorted or stretched.

17a. Remove rods and replace.

17b. Replace bellows if necessary. (See Sections 5K13 through 5K25.)

18. Time check on distance indication disagrees with speed indication. 18a. Master speed indicator not correctly calibrated.

18b. Constant frequency not exactly 60 cycles.

18a. Recalibrate master speed indicator. (See Sections 5M51 and 5M52.)

18b. Check operation of constant frequency unit. (See Sections 5N15, 5N16, 5N17, and 5N18.)

19. Conning tower speed indication disagrees with speed indication of master speed indicator. 19a. Speed transmitter drive gear incorrectly set.

19b. Speed transmitter drive gear hub has slipped on transmitter shaft.

19c. Repeater not on electrical zero.

19a. Reset adjustment to make pointers agree. (See Sections 5M46, 5M51, and 5M52.)

19b. Tighten hub screws and reset adjustment. (See Sections 5M51 and 5M52.)

19c. Set on electrical zero. Readjust transmitter drive gear. See Sections 5M51 and 5M52.)

20. Log components operate correctly, but speed and distance readings disagree with navigator's figures. 20. If error exists after proper allowance has been made for effect of bottom fouling, for wind, and for currents, the pump orifice may not be set at proper correction. 20. Set to percent correction determined by navigator. (See Chapter 6 for the method of calibration on measured courses.)

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