Page 240 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

Control elements for control panel
1 Isolating switch (Fig 7)
Isolating switch (Isolator) is a manually operated mechanical switch which isolates/disconnects the circuit which
are connected with it from the supply system as and when required. It should be normally operated at “OFF” load
condition.
It is available in different current, voltage rating and size.
2 Push button switch (Fig 8)

Push button is a simple push switch mechanism for making or breaking the circuit as and when required. It is
made out of hard plastic or metal. An indicating lamp is incorporated with the push button switch to indicate start
or stop is also available.

Fig 7 Fig 8

3 Indicating lamp (Fig 9)
It is a low voltage, low wattage filament or neon or LED lamps used to indicate the various indication like availability
of supply or motor ON/OFF, mains/motors fails or trip etc.
It is available in different size, colour and wattage. It should be generally fitted in the front side of the control panel
with suitable holder.
4 MCB (Fig 10)

Miniature circuit breaker (MCB) is an electro mechanical protective device which protect an electrical circuit from
short circuit and over load . It automatically turns off, when the current flowing through it exceeds the maximum
allowable limit.

Fig 9 Fig 10

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CITS : Power - Electrician & Wireman - Lesson 93-100 CITS : Power - Electrician & Wireman - Lesson 93-100