Page 198 - An Introduction To Predictive Maintenance

188 An Introduction to Predictive Maintenance

Circuit (open) Any break or lack of contact in an electri-
cal circuit either intentional (switch) or
unintentional (bad connection).
Circuit (parallel) An electrical system in which all positive
terminals are joined through one wire, and
all negative terminals through another
wire.
Circuit (series) An electrical system in which separate
parts are connected end to end, to form a
single path for current to flow through.
Circuit breaker A resettable device that responds to a preset
level of excess current flow by opening the
circuit, thereby preventing damage to
circuit elements.
Circuit protector A circuit protector is a device that will open
the circuit if it becomes overheated because
of too much electricity flowing through
it. Thus, it protects other components
from damage if the circuit is accidentally
grounded or overloaded. Fuses, fusible
links, and circuit breakers are circuit
protectors.
Coil A continuous winding arrangement of a
conductor, which combines the separate
magnetic fields of all the winding loops to
produce a single, stronger field.
Current The flow of electricity in a circuit as
expressed in amperes. Current refers to the
quantity or intensity of electrical flow.
Voltage, on the other hand, refers to the
pressure or force causing the electrical
flow.
Diode A device that permits current to flow in one
direction only. Used to change alternating
current to direct current. A rectifier.
Direct current (DC) Electrical current that flows consistently in
one direction.
Distribution The way in which power is routed to
various current-using sites or devices.
Outside the building, distribution refers to
the process of routing power from the
power plant to the users. Inside the build-
ing, distribution is the process of using