Hello reader, dealing with electricity need attention and
concentration. For this reason, I will like to talk about three
materials were used to either conduct or prevent user to be
electrocuted with electricity.
Conductor:
Electrical conductor is a
material that allow easy flow of
electrical current. According to the above figure 1,you can observed
that, the structure of conductor consist of conduction band, Forbidden bond and valence band. At
conduction bond there is electron which is
negative and at the valence band there’s proton called holes and it is
positive. But forbidden band not visible here, because of attraction of
opposite charges. For this reason, conductor was very sensitive to electric
current, so as a electrician do not play with live conductor, even if you are
saved other people around you are not safe. Remember safety came first. This
means there’s covalent band in conductor. I will like to share an incident
happened at my school, distribution fuse board got contact with burglar
which is a metal and metal is a conductor, so
one of lines in D.F.B was melted this lead to leakage current, were
sitting one of the student touched the burglar and made huge sound I got
shocked! I took my voltage tester to touch the metal, it indicated strong
voltage. I started tracing where is the origin of the problem? I found it was originated from
D.F.B, You heard the danger of conductor .Below is diagram of conductor. 
Conductor have many types. Do you know, not all the
conductor has the same conductivity? Each conductor has it’s own conductivity.
The best among the types was copper. That is reason pure copper is expensive
due to the capability of copper to
conduct electricity and to stand with higher heat. Let look at feeder pillar
fuse was made of copper, it can spend long time without cutoff in normal
condition. Try to just fill feeder pillar
with may be Aluminum, you will see how it will melt like rubber inside fire.
Other types of conductor
include, Aluminum, steel, lead. For aluminum it is used for distribution
network like Higher Tension or Lower Tension lines, it has less expensive, it
is lighter. All the above mention conductors, each one has it’s own
conductivity (Amperes capacity).
Insulator:
It is vital to know each materials
and it’s physical properties, so that you will know how to handle them for
electrical work. There one man who used
flower cutlass to cut twin live cable, that cutlass handle was made of metal,
the man said after the accident, I thought Am going to die, because of severe
shock he was received during the cutting. When he was asked, don’t you know you
were short circuit the circuit and also you are holding conductor? He said I
don’t know.
Now, let start discussion
about insulator which is material whose electrical do not move freely, very
small amount of current ca following in it, depend on the amount of voltage
present. Do you know perfect insulator does not exist? Follow me I will explain
to you. Have ever heard someone try to switch on socket outlet and he became
electrocuted? It was happened at my local area. This was occurred, at the time
of fault 11kv was cutoff and fall on
415v, at that time whoever try to touch switch socket outlet he was dead, and
you know they are insulator. But they became conductor because the present volt
passed the insulation capacity of the switch body. Internal structure of
insulator was shown in fig 2 above.
It consist of three layers
namely; conduction band, forbidden band and valence band. The forbidden band is
the region between conduction band and valence band,at conduction band there is
an electron which negative charge, while at valence bond there is proton which
is called holes(positive charge). As we know electron has the velocity to move
despite there’s gap in forbidden band, sometime it can happen on electron or
more to jump forbidden band, and lead to conduction of electric current. that
is reason not all the insulator you will use during maintenance, check the
amount of voltage you are going to work on. Safety came first.
Diagram of insulator with level:
Types of insulator:
1-Glass
2-Paper
3-Teflon
4-Polymers
5-Plastics.
Uses:
v
It reduce fire hazard
v
It not allow
short circuit
v It prevent electromagnetic wave reflection.
Insulator can found all the three stages of electricity namely,
Generation, Transmission and Distribution, and it can be identified by size.
Higher voltage must carry big insulator than lower voltage.
