Module 3—Introduction to Circuit Protection, Control, and Measurement
i - ix
, 1-1 to 1-10
1-11 to 1-20
, 1-21 to 1-30
1-31 to 1-40
,1-41 to 1-50
1-51 to 1-60
, 1-61 to 1-70
1-71 to 1-73
, 2-1 to 2-10
2-11 to 2-20
, 1-21 to 2-30
2-31 to 2-40
, 2-41 to 2-42
3-1 to 3-10
,3-11 to 3-20
3-21 to 3-30
, 3-31 to 3-39
AI-1 to AI-3
, AII-1 to AII-2
AIII-1 to AIII-10
b. Outside connector
A21. Visual inspection, indicators, and using a meter.
A22. Put it back in the circuit. A good fuse will have zero ohms of resistance.
A23. The ohmmeter causes more than 1/500 ampere through the fuse when you check the fuse, thus it opens
A24. Use a resistor in series with the fuse when you check it with the ohmmeter.
A25. Turn the power off and discharge the circuit before you remove fuses. Use a fuse puller (an insulated
tool) when you remove fuses front clip-type fuse holders. When you check fuses with a voltmeter, be careful to
avoid shocks and short circuits.
a. Not acceptable-wrong style
#3-smaller current rating
c. Substitute #1-identical, except higher voltage rating
acceptable-lower voltage rating
e. Direct replacement
f. Not acceptable-higher current rating g. Substitute #2-Faster time delay rating
A27. Check for the proper type of replacement fuse and proper fit.
A28. Be sure the power is off in
the circuit and the circuit is discharged before replacing a fuse. Use an identical replacement fuse if possible.
Remove any corrosion from the fuseholders before replacing the fuses.
A29. Improper fuse, corrosion,
improper fit, and open fuse.
A30. Frame, operating mechanism, arc extinguishers, terminal connectors,
and trip element. A31. Thermal, magnetic, and thermal-magnetic.
A32. The thermal trip element makes use of
a bimetallic element that bends with an increase in temperature or current. The bending causes the trip bar to be
moved releasing the latch.
A33. A circuit breaker that will trip even if the operating mechanism is held
A34. A circuit breaker that can be overridden if the operating mechanism is held ON. A35. In current
sensitive or nonemergency systems.
A36. In emergency or essential circuits.
A37. Instantaneous, short time delay, and long time
A38. It is the use of time delay ratings to cause the circuit breaker closest to the faulty
circuit to trip.
This isolates the faulty circuit without affecting other circuits.
time delay; CB2, CB3-short time delay; CB4 through CB10-instantaneous.
A40. The power requirements of
the circuit and the physical space available.
A41. A push button or push-pull circuit breaker (small size,
A42. Check the applicable technical manual, obtain the approval of the electrical or
engineering officer (for shipboard circuit breakers), remove power from the circuit breaker, and tag the switch
that supplies power to the circuit breaker.
A43. Check the operating mechanism for smooth operation,
check the contacts for pitting, check the terminals for tightness and corrosion, check the mounting hardware for
tightness and wear, check all components for wear, and check the entire circuit breaker for cleanliness.
Introduction to Matter, Energy, and Direct Current,
to Alternating Current and Transformers, Introduction to Circuit Protection,
Control, and Measurement
, Introduction to Electrical Conductors, Wiring Techniques,
and Schematic Reading
, Introduction to Generators and Motors
Introduction to Electronic Emission, Tubes, and Power Supplies,
Introduction to Solid-State Devices and Power Supplies
Introduction to Amplifiers, Introduction to
Wave-Generation and Wave-Shaping Circuits
, Introduction to Wave Propagation, Transmission
Lines, and Antennas
, Microwave Principles,
, Introduction to Number Systems and Logic Circuits, Introduction
to Microelectronics, Principles of Synchros, Servos, and Gyros
Introduction to Test Equipment
, Radar Principles,
The Technician's Handbook,
Master Glossary, Test Methods and Practices,
Introduction to Digital Computers,
Magnetic Recording, Introduction to Fiber Optics