ISOLATED RECEPTACLE CIRCUITS
extension cord before you insert the extension
cord plug into a live receptacle.
Isolated receptacle circuits are installed on all new
After using the tool, unplug the extension cord
construction ships. These circuits are individually
isolated from the main power distribution system by
from the live receptacle before you unplug the
isolation transformers. Each circuit is limited to 1,500
tool cord from the extension cord. Do not unplug
feet in length to reduce the capacitance to an acceptable
the cords by yanking on them. Always remove
level. This design is intended to limit ground leakage
the plug by grasping the plug body.
currents to 10 mA, which would produce a nonlethal
When using portable electric tools, always wear
shock. These receptacles are located where personnel
rubber gloves and eye protection.
usually plug in electric-power tools or appliances. To
maintain a safe level of leakage currents, make sure the
If you notice a defect, return the tool to the ship's
isolated receptacle circuits are free of all resistance grounds.
tool issue room (TIR).
When tools produce hazardous noise levels, wear
TEST EQUIPMENT
hearing protection.
Test equipment is precision equipment that must be
Another good practice to establish (at the discretion
handled with care if it is to perform its designed
of the commanding officer) is to list the portable
functions accurately. Some hazards to avoid when
equipment that requires testing more or less often than
using test equipment include rough handling, moisture,
once a month, depending on conditions in the ship.
and dust.
Where PMS is installed, tests should be conducted
following the maintenance requirement cards (MRCs).
Rough handling includes bumping or dropping
equipment. Bumping or dropping test instruments may
distort the calibration of the meter or short-circuit the
ELECTRIC SOLDERING IRONS
elements of an electron tube within the instrument.
When using and handling an electric soldering iron,
Moisture effects are minimized in some types of
you can avoid burns or electric shock by taking the
electronic test equipment, such as signal generators and
following precautions:
oscilloscopes, by built-in heaters. Operate these heaters
for several minutes before applying the high voltage to
Grasp and hold the iron by its handle. Always
the equipment.
assume a soldering iron is hot, whether it is
plugged in or not. Never use an iron that has a
The meter is the most delicate part of test
frayed cord, damaged plug, or no safety
equipment. You should protect a meter by making sure
inspection tag.
the amplitude of the input signal being tested is within
the range of the meter.
Hold small soldering workplaces with pliers or a
Since the moving coils of the meter in electric test
suitable clamping device. Never hold the work
equipment are of the limited-current type, they can be
in your hand.
permanently damaged by excessive current. When
Always place the heated iron in its stand or on a
using test equipment, you should observe the following
metal surface to prevent fires or equipment damage.
safety precautions and procedures:
Clean the iron by wiping it across a piece of
Never place a meter near a strong magnetic field.
canvas placed on a suitable surface. Don't hold
Whenever possible, make the connections when
the cloth in your hand. Don't swing the iron
the circuit is de-energized.
to remove excess hot solder. Swinging the iron
could cause a fire in combustible materials or
When connecting an ammeter, current coil of a
burn other personnel in the area.
wattmeter, or other current-measuring device,
Before soldering electrical or electronic
always connect the coils in series with the
load-never across the line.
equipment, make sure it is disconnected from its
power supply.
To measure a circuit, the potential coil of a
After soldering, disconnect the iron from its
wattmeter, or other instrument, connect the
power supply. Let it cool before you store it.
voltmeter across the line.
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