3-17 Maintenance procedures
To prevent electrical shock, open circuit breaker 6P14 on 24 Vdc power panel. Redtag circuit
breaker with "WARNING - DO NOT ACTIVATE. REPAIRS BEING MADE." Also, wear hearing
protection when servicing foghorn.
Due to mission and crew capabilities of this vessel, maintenance normally assigned to higher
echelon may be assigned to the crew.
3-17.1 General maintenance. Perform appropriate general maintenance in paragraph 2-18. Clean and inspect
electrical components as follows:
Wipe clean exterior of electrical component with clean rag. Vacuum clean or clean inside with electrician's
brush. Avoid using solvents for cleaning inside of component. Solvents leave a greasy film on components that
may reduce electrical continuity.
Visually inspect for indications of burns, corrosion, loose connections, damaged parts, or chipped paint. Clean
corrosion from contacts and terminals, tighten loose connections, and replace damaged parts. Clean electrical
contacts with silver polish, fine sandpaper, or burnishing tool. DO NOT use emery paper or steel wool. Vacuum
to remove residue. Touch up paint according to TB 43-014. Do not paint threads or labels.
3-17.2 Equipment maintenance. Perform foghorn maintenance in accordance with paragraph 4.0, Maintenance, of
manufacturer's service manual/instructions as appropriate.
3-17.3 Foghorn remote control assembly circuit test
With 24 Vdc power panel circuit breaker 6P14 closed (ON), check voltage at 24 Vdc inputs to regulator
(converter assembly) for 24 Vdc (see Figure 3-2). If voltage is not 24 Vdc, go to step b. If voltage is 24 Vdc, go
to step c.
Check voltage at breaker 6P14 output for 24 Vdc. If voltage is not 24 Vdc, circuit breaker or power source is at
fault. If voltage is 24 Vdc, repair or replace power cable from 6P14 to regulator cable.
Check voltage at outputs of regulator converter for 12 Vdc. If voltage is 12 Vdc, go to step d. If voltage is not 12
Vdc, replace regulator converter.
Check voltage and polarity to remote control assembly across terminal board points 6 (+) and 7 (-) for 12 Vdc. If
voltage is 12 Vdc, go to step e. If voltage is not 12 Vdc, repair or replace power cable from regulator converter
assembly 12 Vdc outputs to remote control assembly TB6 and TB7 as given in paragraph 3-17.5.
Check voltage and polarity at regulator oscillator terminal board across point 1 (+) and 4 (-) for 12 Vdc. If voltage
is 12 Vdc, go to step f. If voltage is not 12 Vdc, repair or replace cable from remote control assembly TB6 (+)
and TB7(-) to oscillator/regulator PC assembly TB1 (+) and TB4 (-).