October 2016
A platform to learn electrical wiring, single phase, 3 phase wiring, controlling, HVAC, electrical installation, electrical diagrams.
As you know that Safety is important in electricity works. Today i am writing about shunt trip breaker wiring diagram which related with safety and protection of electricity. As you know that electricity is dangerous but it's become more dangerous when it's upgrade from the 220 volts to 3 phase 440 volts. As you that mostly we use 3 phase  system in industrial state where we can not protect our electrical distribution using RCD (residual current device).
In Single phase wiring or house wiring we use electric power supply between phase and neutral which can be control by using a simple double pole RCD Breaker. But When it's come to high load places or where we use the three phase supply then use a MCCB (module case circuit breaker) Shunt trip circuit breaker with emergency push button switch which we know better with name of EPO (emergency power off) button.

Shunt Trip Breaker Wiring Diagram with EPO Button.

In this post i am just tell you about wiring of single EPO button with shunt trip MCCB breaker. In industrial state,  Electric operator duty is to operate the machinery and his duty is on the front of Main panel board.
Now if a short circuit is done in electrical instillation or other electrical accident, the operator can easily push a small push button switch and the all electric power supply will powered off. If we comparison it between switching off the main circuit breaker then it's will get more time.
In the advantages of shunt trip breaker, a most important things is that we can instill the emergency switch (EPO) anywhere, from where can easily push button or where the push button is near to us.

One thing more that we can instill more then one EPO buttons for one breaker and every button will work same. However is this post shunt trip breaker wiring diagram i shown only one EPO button and INSHALLAH in next post i will show you instillation of  multi EPO (emergency power off) buttons for a single shunt trip MCCB breaker.

Also read below
How to wire 3 or 4 pole MCCB Breakers?
How to wire RCD Breaker?
How earthing system works?

How Shunt Coil Work

In simple words, a shunt trip a electromagnetic coil which make magnetic field by providing external power source. In the coil a move able rod is fixed with spring and when we provide the supply
The shunt trip move able rod hit the tripping point or disconnecting point of circuit breaker internally and the breaker become off or trip.
In the MCCB circuit breaker, we have a push able button or place which is named with "push to trip" and when we switch on the breaker and push this button the breaker become switch off and trip due to pushing this button.
The shunt trip coil rod push this point internally when the shunt coil is operate.

Here is some images of shunt coils and after that we will discuss the shunt trip breaker wiring diagram with image + symbol diagram.

Shunt Trip Device

breaker shunt trip coil

shunt tripping device

Now lets how to wire shunt trip device (accessory), it's too simple as i shown in above shunt trip device images that a shunt coil have only to wires , just like a magnetic contactor or magnetic relay coil. But you must provide the power source regarding coil rated volts. You can find out the rate coil label on shunt coil, circuit breaker or on shunt trip coil.
But the question is that how to wire it. And the answer is that "it's also too simple".
We use a push button switch for shunt coil which we know with it's short name "EPO" which i discuss in my above words.
In EPO switch we have four terminals in which tow are Normally close with each other and other two are normally open.
So we need to provide the supply / current to the shunt trip device circuit breaker when the emergency moments come.

I.e example " if we have a shunt trip coil which is operate on 220 volts, so we need to provide the 220 volts AC current to shunt trip coil to operate or to do trip the breaker in emergency time. So our neutral will be connect direct to the shunt tripping coil and Phase (hot wire) will be connect to coil other side through the EPO push button switch normally open contacts.
So the EPO switch will be normally open and when we push the switch in emergency time the switch normally open contacts will make a close contacts connection and the hot wire current start flowing to the coil and complete the circuit because the neutral wire current is already connect to coil. So the coil will make a magnetic field and push the rod, the rod will press the trip point and breaker will disconnect the power supply to load.

Here is complete explanation of shunt trip circuit breaker wiring diagram which help you understanding completely.

shunt trip breaker wiring diagram

What is the purpose of a shunt trip circuit breaker

The main purpose of a shunt trip breaker is that we can easily switch off main circuit breaker form our nearest place in short time and can safe us from electrical accidents.

Final words
To wire a shunt tripping breaker follow the below steps.

  • First of all wire your Circuit breaker.
  • Then connect the neutral wire to shunt trip coil.
  • Then connect the Phase (hot wire) to the EPO button normally open contact.
  • Then get connection form EPO other side of normally open contact and connect to the shunt trip coil.
That's all you done it, in the above diagram, i shown the complete the of shunt trip circuit breaker wiring diagram using image and symbol diagram, however now if you have any question regarding the shunt trip breaker wiring diagram  with emp switch or want to gave us some suggestion then use the below comments section below.

A platform to learn electrical wiring, single phase, 3 phase wiring, controlling, HVAC, electrical installation, electrical diagrams.
As you known that capacitor are numbering in those electrical and electronics component which we use very much in different circuits for different uses. In this post i am just writing about that what capacitor and how it's works.

Capacitor Definition and Explanation

Capacitor (Cap) is a component which consists of conducting surface separated by by a non-conductive region or by a layer of on insulating me dim called dielectric. Note that the non-conductive region mean also dielectric.
or An example of dielectric is that it's a electrical insulator. I.E example is glass, air, paper, vacuum can be use as dialectic in capacitor.

The purpose of capacitor is that to store electrical energy by using electrostatics. capacitor can better explain by below definitions.

  • In simple words a Cap is an electronic component which can story the electrical energy from of electrostatic field is called Cap... or condenser. Note that we also called condenser to Cap...
  • A device which is consists with two metal plates, in which any insulating medium use between palates as dielectric is called cap....
  • If we place two conductor plates near with one another and place a insulating material between the plates and provide the electric charge to plates from potential difference source (voltage) source is called Capacitor.
  • Any two conductors in which electric flied can be maintained is a from of cap..
  • In  simple words a CAP is a electrical device which is consists two conductive plates in parallel and which is separated by an insulating material is called dielectric.
Also Read Below

In capacitor we have connecting leads which is connected to these parallel conductive plates. In the blow diagram i shown internal structure - construction of capacitor and it's circuit symbols.

capacitor structure and capacitor symbol diagram

In the above diagram i shown the Cap symbols which we use in circuit for Cap. If we have an paralleled plate type of CAP. So one plate supply wire is connected to positive end and other is to negative or earthed. When we connect link of this type of  Capacitor to the battery supply. So the electron flow start from plate A to plate B for a time. (It's happened because Plate A can bearer more charge due to plate B earthed)
Due the negative electron emission from plate A and Plus to B plate. Due this electron emission- the positive charge on plate A and negative charge on Plate B.

A platform to learn electrical wiring, single phase, 3 phase wiring, controlling, HVAC, electrical installation, electrical diagrams.
In house wiring, we install two types of wiring in which one 3 phase wiring installation for house and other one single phase installation. In this post you will learn how to install three phase electrical wiring using a simple diagram in which i shown how to install three phase 4 wire system in a multi story building. One thing more that i shown 3 distribution boards in which every story have there own electrical main distribution board.

3 Phase Wiring installation In Multi Story Building / House

The three phase 4 wire system installation in home is very simple but to understand you must study each part of this class and devices which i use in the below diagram. I start from this from step one.

Utility Pole 3 Phase 4 Wire System

In the diagram is start from the utility pole and i get service line supply from utility pole to 3 phase kWh energy meter. This utility pole connect to step down transformer (supply from sub station). My means that the pole supply comes from the substation or step down transformer.

3 Phase kWh Energy meter

I also shown the wiring diagram for there phase 4 wire system kWh (kilowatt-hours) meter, I also published a post about the wiring and installation of three phase four wire system kWh energy meter. So kindly read the below article if you did not understand the method of 3 phase kWh energy meter connection.

Also read
How to wire and install the 3 phase kWh energy meter?
How to wire Single phase kWh meter?

4 Pole MCCB Breaker

After the connection of energy meter, i connect the 3 Phase 4 wire power supply to the MCCB (module case circuit breaker). However if you can do this connection then read the below post.
Also read
How to wire 3 Pole or 4 Pole MCCB Breakers?

Now come to the connection for distribution board for one story. The method of installation 3 phase wiring is simple, you divide your load in three parts and each part have there own Line (phase). My means that divide your load in 3 parts and provide one one phase to each part.
Now here i have multi story building in which each story have there own single phase distribution board.
So we will provide one one phase or line to each story. And our neutral will be common but this will be common in circuit breaker output point and each story have there own neutral wire. So provide my Line 1 or phase 1 to the first distribution board and you can see in diagram. So come to Distribution board.

Distribution Board Wiring Connection

In the db board, i use the following electrical devices.

Double Pole MCB Circuit Breaker 63 Amps

I get phase and neutral wire from the main circuit breaker( 4 pole MCCB) and connect to double pole MCB (miniature circuit breaker). Note that double pole MCB will be consider a main circuit breaker for single phase distribution board for below diagram.

Also read below
How to wire double pole MCB breaker?
How to wire and install single , double , three and four pole MCB (miniature circuit breakers)?

RCD Brekaer.
I also install and wire double pole RCD (residual current device) in each distribution board. If you did not understand the wiring and installation of RCD then read the following post.

Distribution Electrical board Wiring for Single phase
How to wire and Install the double pole RCD breaker?
How to wire a 4 pole RCD circuit breaker?

Earthing or Ground connection

I also done the earthing connection in 3 phase wiring installation diagram in multi story house. I shown this connection by using a earth symbol and green wire. In the below diagram the earth symbol consider as earth electrode.

Also read
How earthing system works for protection?

AC Voltmeter Wiring connection for single phase

I also do the voltmeter wiring connection is each distribution board and you can see it in diagram. However here is some post which help you more then this. (Note that the VM denote the ACV voltmeter in below diagram.

Also read
How to wire a voltmeter for single phase?
How to wire a voltmeters for Three phase?
How to wire voltmeter selector switch for 3 phase with volt meter?
How to install the volt meter selector switch for 3 phase 4 wire system?
How to wire light indicator for 3 phase 4 wire system?

Ampere meter / Ammeter connection with CT (current transformer)

I also shown the ammeter connection with current transformer in 3 phase installation diagram for multi story house. The connection of CT is simple with ammeter but this will be better for you if you read the following articles.

How to wire a ammeter for AC and DC?
How to wire ammeter with current transformer?
How to do digital ampere meter connection with CT Coil?

Complete Explanation of Three - 3 phase wiring installation in a multi story building

The installation of three phase 4 wire system in multi story building is simple if you want to use single phase supply for each story. Note that by doing this type of connection you must wire 4 distribution board where one for main MCCB circuit breaker and other for each story. And you can also do these connection in a single main DB but you must use a big size  distribution board box where you can easily install all circuit breakers. But if use there own distribution board in every story then this will be better option.

So let's do it step by step.
In the 3 phase wiring diagram i shown a utility pole from where i get service line connection for 3 phase kWh meter (energy meter). Now i connect the supply wire Red, Yellow , Blue and Black to the energy meter input connection terminals and get supply from energy meter out going connection to load.
One thing more that that we use color code of red yellow and blue when we are doing the three phase wiring but when it's come to the 3 phase four wire system, we use the black for neutral. And when we are gonna to doing connection of single phase ( current between phase and neutral) then we use red for phase (hot wire) and black for neutral.

After the connections of three phase kWh meter we provide the 3 phase 4 wire supply to 4 pole MCCB circuit breaker which on th- 100 amp. Now the next step is outgoing supply from the 4 pole MC CB circuit breaker. The N neutral wire will be common for each story or load and you see it in the below diagram, that i connect the neutral black color wire from the breaker and wire it with a connection point connector.

So the neutral will be common for each story or distribution board and one one phase will be distribute to the each story. So i connect the neutral wire to a neutral connection point or connector from where we can get connection of neutral for load.
I connect a neutral wire to this neutral connection point and connect to the story 3 distribution board double pole MCB breaker. And then i get Phase wire from the MCCB and connect to this MCB breaker. Then MCB supply goes to the double pole RCD and you can see it in below diagram. Note these two breaker are 63 amps.

3 phase wiring installation diagram

Now from the RCD breaker the neutral wire goes to neutral connection point as i shown in above 3 phase wiring diagram and the phase (hot wire) red color is goes to all single pole MCB breakers which i shown in above diagram.
In the above3 phase wiring diagram the 2 single pole breaker are 16 amp , 2 are 10 amps and other sex are 6 ampere breaker. Note that this just in example and you must install or wire breaker regarding your total load. Note that use high quality wire for your wiring system. And always chose or use the wire regarding load (amps).

I also wire the voltmeter in above three / 3 phase wiring third story building wiring, for which i get hot wire connection from input points of single pole MCB breakers and neutral from neutral connection connector point. And same i wire the light indicator.
In the above diagram i shown the ammeter connection with current transformer (CT coil) and also provide the complete method of wiring and installation of ammeter with current transformer in above links. However use always the current transformer regarding the ammeter requirements. If the ammeter is 60/5 then use a current transformer with same value 60/5.
You can also use AC series type of ammeter but the CT type ammeter is better then ammeter which we use between supply in series connection.

As i shown in above 3 phase wiring diagram that i do the earthing connection, and provide the earth wire to each point. I shown in bottom of diagram earth symbol with name of earth electrode and from here i provide the ground connection to all story loads / rooms etc. And in each story i use the earth connection point, from where a person can provide the earth wire to any load / electrical machine, outlets etc.

In the above 3 phase wiring diagram 1,2,3,4..... in circle means that these wire goes to load 1 , load 2 and load 3. It's mean that if the 1 hot wire (phase - red) wire goes to the room A then the neutral 1 (black wire) is also for the room A and the earth connection 1 number wire is also for the same point (load- room A).

Follow the same method for story 1 and story 2, but provide the L2 (phase 2 - Hot wire 2 ) to the story 2 and Line 3 to story 1 which is bottom of 3 phase wiring diagram. However lets get another review on diagram step by step.

3 Phase Wiring Step By Step Guide Multi Story Building

  • First of all provide the serves line wire to the 3 phase kWh meter from utility pole.
  • Then provide the 3 phase 4 wire supply to 4 pole MC CB Circuit breaker.
  • Then connect the neutral point from MC CB to neutral connection point.
  • Then get connection from the main neutral point and connect to story 3 or other story double pole MCB circuit breaker.
  • The connect the L1 to the story three double pole MCB between the CT (current transformer) and from MCB connect neutral and phase to the RCD circuit breaker. (Note some people know RCD with name of ELCB  (earth leakage circuit breaker).
  • Then from RCD connect the neutral wire to neutral connection point and phase to circuit single pole breakers.
  • Then provide the supply to the voltmeter and indicator light.
  • Then Do connection between CT coil and ammeter.
  • Then provide the earth connection (green wire) to story three earthing connection point.
  • Then provide the supply to each loads from circuit breaker , neutral connection point and earth / ground connection connectors.
That's all , same follow this method for each story. but provide there own different phase wire and neutral wire.


This in example of 3 phase wiring installation in multi story building, and i use different ampere circuit breaker, just for your understanding. However always use breaker regarding your load. Now i hope you understood the 3 phase wiring in multi story house or building, now if want gave us suggestion or any question then use the below comments section.