Functional switching Functional switching involves the switching off, varying the sup-
ply, electrically operated equipment normal service.
Gravitational force Gravitational force the force acting towards the centre the earth due to
the effect gravity. Under fault conditions will melt
when overcurrent flows, protecting the circuit conductors from damage.
Instructed person instructed person person adequately advised supervised skilled
persons able avoid the dangers which electricity may create.
Insulator insulator material, usually non-metal, which the electrons
are very firmly bound the nucleus and, therefore, will not allow heat or
.
Fuse fuse the weakest link the circuit.
Force The presence force can only detected its effect body.
Impedance The total opposition current flow a. causes the current the circuit lag behind the applied voltage.
Heating, magnetic chemical The three effects electric current: When electric current flows a
circuit can have one more the following three effects: heating, mag-
netic chemical. current inductive
circuit.
Inertial force Inertial force the force required get things moving, change direction
or stop.
Hazardous area area which explosive gas–air mixture present called hazard-
ous area, and any electrical apparatus equipment within hazardous
area must classified flameproof protect the safety workers’.Glossary terms
378
Flexible conduit Flexible conduit manufactured 731-1: 1993 made interlinked
metal spirals often covered with PVC sleeving. However, test unlikely identify cracked socket outlet, a
chipped loose switch plate, missing conduit-box lid saddle, is
also necessary make visual inspection the installation.
Friction force Friction force the force which resists prevents the movement two
surfaces contact.
Hazard risk assessment Employers more than five people must document the risks work and
the process known hazard risk assessment.c.c. force
may cause stationary object move bring moving body rest.
Hazard hazard something with the ‘potential’ cause harm, for example,
chemicals, electricity working above ground.
Fluorescent lamp fluorescent lamp linear arc tube, internally coated with fluorescent
powder, containing low-pressure mercury vapour discharge.
Inspection and testing techniques The testing installation implies the use instruments obtain
readings. circuit called impedance
and given the symbol Z.
Inductive reactance Inductive reactance (XL) the opposition a. All existing
installations should periodically inspected and tested ensure that
they are safe and meet the regulations the IEE (Regulations 610 634)
