This presentation summarizes different types of insulators used in electrical engineering. It introduces pin insulators, suspension insulators, strain insulators, shackle insulators, post insulators, and bushing insulators. Pin insulators are used to support conductors up to 33kV. Above 33kV, suspension insulators made of strung porcelain discs are more economical. Strain insulators are used at line ends or sharp curves to relieve tension. Shackle insulators were formerly used as strain insulators for low voltage lines. The presentation was given by electrical engineering students at LCD for their class.

1. WELCOME
TO MY PRESENTATION
BY A.A.MALI
•

2. Electrical Engineering Dept.
LCD Presentation
ON
“INSULATOR”
Presented By:
1) PRANJAL BABAR.
2) ATISH MALI.
3) MUJAMIL SHAIKH.
Guided By:
Prof. N.V. KHANDEKAR

3. CONTENTS OF THE INSULATOR
.

4. 01 POST
INSULATO
R
SUSPENSI
ON
INSULATO
R
PIN TYPE
INSULATO
R
02 03

5. SHACKLE
INSULATO
R
BUSHING
INSULATO
R
04 05 06
STRAIN
INSULATO
R

6. WHAT IS AN INSULATOR :-
i) The overhead line conductors should be supported on the poles or towers in such a
way that current forms conductor do not flow to earth through supports i.e. line co-
nductor must be properly insulated forms supports
ii) This is achieved by securing line conductors to supports with the help” insulators”.
Iii) Insulators provide necessary insulation between line conductors & supports &
leakage current from conductor to earth .

7. PROPERTIES OF INSULATOR :-
i) High mechanical strength .
ii) High electrical resistance of insulator material.
iii) High relative permittivity of insulator material.
iv) High ratio of puncture strength to flash over .
v) The insulator material should be non-porus face from impurities & crucks .

8. PIN TYPE
INSULATOR
01

9. PIN TYPE INSULATOR :-
i) The pin type insulator is secured to the cross-arm arm on the pole.
Ii) There is a groove on the upper end of the insulator for housing the conductor,The
conductor the passes through this groove & is bound by the annealed wire of the
the same material as the conductor.
Iii) pin type insulator are used for transmission & distribution of electric power at
voltage upto 33kv . Beyond operating voltage of 33kv ; the pin type insulators
become to bulky & hence uneconomical.

10. SUSPENSION TYPE INSULATOR
02

11. SUSPENSION TYPE INSULATOR : -
i) The cost of pin type insulator increase rapidly as the working voltage is increased.
Therefore, this type of insulator is not economical beyond 33kv for high voltage
( >33kv), it is a usual practise to use suspension type insulator .
ii) They consist of a porcelain discs connected in a series by metal links in the form of
a string .
Iii) Each disc or unit is designed for low voltage say kv the number of disc
in series would obviously depend upon the working voltage .
Iv) Each disc or unit is designed for low voltage , say kv . The number of
disc in series would obviously depend upon the working voltage
c
v
c
c
c
v
c
c
c
v
c
v

12. ADVANTAGES :-
1) The suspension arrangement provides greater flexibility to the line .
2) This arrangement provides practical protection form lightning .
3) Suspension type insulator are cheaper than pin type insulator for voltage beyond
33kv .
4) If any one disc is damaged , the whole string does not become useless because the
damaged disc can be replaced by the sound one .

13. STRAIN INSULATOR
03

14. STRAIN INSULATOR :-
i) When there is dead end of the line or there is corner or shorp curve , the line is
subjected to greater tension.
Ii) In order to relieve the line of excessive tension; strai insulator are used.
Iii) For low voltage line ( < kv), shackle insulator are used as strain insulators .
Iv) However for high vtg. Transmission lines , strain insulator consist of an assembly
of submission insulators .
V) The discs strain insulator are used in the verticle plane , when the tension in lines
is exceedingly high as act long river spans , two or more strings are used in parallel

15. SHACKLE INSULATOR
04

16. SHACKLE INSULATOR :-
i) In early days , the shackle insulators were as strain insulators , But now a days ,
the are frequently used for low voltage distributed lines .
ii) Such insulators can be used either in a horizontal position or in a vertical
position .
iii) They can be directly fixed to the pole with a body or to the cross arm .
iv) The conductor in the groove is fixed with a soft binding wire .

17. POST INSULATOR

18. POST INSULATOR

19. BUSHING INSULATOR

20. DEPARTMENT OF –
ELECTRICAL
& ALL LISTERNS