Security lighting Security lighting the first line defence the fight against crime.
Short circuit short circuit overcurrent resulting from fault negligible imped-
ance connected between conductors.
Shearing force Shearing force the force which moves one face material over another.
Simple machines machine assembly parts, some fixed, others movable, which
motion and force are transmitted.
. The UPS is
plugged into the mains supply and the computer systems are plugged into
the UPS.
Socket outlets Socket outlets provide easy and convenient method connecting por-
table electrical appliances source supply. With the aid machine are able to
magnify the effort exerted the input and lift move large loads the
output.
Sounders The positions and numbers sounders should such that the alarm can be
distinctly heard above the background noise every part the premises.
Skilled person skilled person person with technical knowledge sufficient experi-
ence able avoid the dangers which electricity may create.
Skirting trunking Skirting trunking trunking manufactured from PVC steel and the
shape skirting board which frequently used commercial buildings
such hospitals, laboratories and offices.
Shock protection Protection from electric shock provided basic protection and fault
protection.c.
Speed Speed concerned with distance travelled and time taken.
Secure supplies UPS (uninterruptible power supply) essentially battery supply elec-
tronically modified provide clean and secure a.
Silicon rubber Introducing organic compounds into synthetic rubber produces good
insulating material such FP200 cables.
Space factor The ratio the space occupied all the cables conduit trunking to
the whole space enclosed the conduit trunking known the space
factor.
SI units units are based upon small number fundamental units from which
all other units may derived.Glossary terms
382
Safety first isolation must ensure the disconnection and separation electrical equipment
from every source supply and that this disconnection and separation is
secure. the cell con-
nected suitable electrical supply, electrical energy stored the
plates the cell chemical energy.
Single PVC insulated conductors Single PVC insulated conductors are usually drawn into the installed con-
duit complete the installation.
Secondary cells secondary cell has the advantage being rechargeable. supply
