d.
Polyvinylchloride (PVC) PVC used for cable insulation thermoplastic polymer.
Phasor phasor straight line, having definite length and direction, which rep-
resents scale the magnitude and direction quantity such cur-
rent, voltage impedance.
Relay relay electromagnetic switch operated solenoid.Glossary terms
381
Personal protective equipment PPE defined all equipment designed worn, held, protect
(PPE) against risk health and safety.
Risk assessments Risk assessments need suitable and sufficient, not perfect. Each size plastic plug colour-coded match a
wood screw size.d.
Power Power the rate doing work. the regulation to
be met ‘so far reasonably practicable’, then risks, cost, time, trouble
and difficulty can considered.
PVC/SWA cable installations Steel wire armoured PVC insulated cables are now extensively used on
industrial installations and often laid cable tray.
Reasonably practicable absolute the requirement the regulation absolute, then that regulation must
be met regardless cost any other consideration.
Power
Work done
Time taken
W
)
Pressure stress Pressure stress measure the force per unit area.
Pressure stress
Force
Area
N/m
)
2
Primary cell primary cell cannot recharged. This also called the volt drop terminal volt-
age, since emf and p.
Risk risk the ‘likelihood’ harm actually being done. Once the active chemicals are
exhausted, the cell must discarded.
Potential difference The potential difference (p.) defined the cosine the phase angle between the
current and voltage.
Rubber Rubber tough elastic substance made from the sap tropical plants. are both measured volts.
.f.
Power factor Power factor (p.) the change energy levels measured
across the load terminals.
Resistance any circuit, resistance defined opposition current flow.
Protective equipotential bonding This equipotential bonding for the purpose safety.
Plastic plugs plastic plug made hollow plastic tube split half its length to
allow for expansion.
Resistivity The resistivity (symbol the Greek letter ‘rho’) material defined as
the resistance sample unit length and unit cross-section
