MOTOR CONTROLLERMOTOR CONTROLLER

Motor ControllerMotor Controller

Motor controller is a one system are consist of combination devices to control the single phase or three phase motor.

In others word to protect the motor become safety use.

For ac we call as a driver or controller but for ac call as a starter.

Motor Controller FunctionalityMotor Controller Functionality1. To start and stop the motor.Single Phase or three phase

motor.2. To avoid the motor starting itself after breakdown. ( No-volt coil or No-volt release concept )3. To minimize starting current,such as star delta , auto-

transformer and rotor resistance starter.4. To avoid any sparking and burning at the motor.5. To start the motor step by step or other types of

controller such jogging control and rotor resistance starter.

6. Operation the motor are in safety user and far away controller.

Types of starter.Types of starter.

1. Direct On line starter

2. Star- Delta starter

3. Auto-transformer starter

4. Rotor Resistance starter

Advantages of the Motor StarterAdvantages of the Motor Starter

Less mechanical force to the motor coil. Less mechanical enjakulasi to the motor

frame,shaft and transmission in the motor. Motor can rotate step by step depending to

the load. Reduce voltage drop to the motor. Reduce any supply system disturbing

ecspecially high hp/amp of the motor.

Disadvantages of the Motor StarterDisadvantages of the Motor Starter

Reduce torque of the motor. High cost to prepared starter component. Need maintenance to the motor. Complicated devices

Starter ComponentStarter Component

1. Contactor

As a electromagnetic switches. Two types 240V and 415V. Will operate when voltage supply to the contactor

coil . All auxiliary will operate from NO to NC and NC

to NO when the coil energized. No-volt coil or No-volt release concept All the auxiliary contactor will release will spring

action when magnetic force are discharge.

Contactor ConceptContactor Concept

Magnetic Force

Auxiliary contact

Constant Contact

Magnetic Force

Contactor FigureContactor Figure

Contact Frame

Constant Contact Cross Bar

Core Pin

Laminated iron Core

Operating Coil

Laminated iron Core

Plate

Base

Spring Contact

ontactAuxiliary C

Pushing Spring

Supply

CONTACTOR COMPONENTCONTACTOR COMPONENT

MAIN CONTACT- To control Main CircuitMengawal litar utama. - Conductor Size are depend on the rating current.

AUXILIARY CONTACT- Low current- contact 5A.- Small contact- Only control for control circuit.

OPERATION COIL- To produce electromagnet at iron core. - Will energize when electricity are supply to iron core.

VARIABLE IRON CORE- To move cross bar after coil energized assist by spring.

CONSTANT IRON CORE- Laminated.- Will energized when electricity are supply.

PUSHING SPRING- Push the core to the condition before after supply off.

OPERATION CONCEPTOPERATION CONCEPT

- Functions with 240V and 415V incoming supply.- Coil will energized when electricity are supply to

the coil and electromagnetic occurred.

- Constant contact are push to top and move the crossing bar/plate.

- Crossing bar will move the main contact from open to close and close to open.

- Contact size are depend on the carried rating current.

MAINTENANCEMAINTENANCE

- Always clean the contactor contact inside..- Make sure spring tensionalin good condition- Tighting screw could be in good condition.

ADVANTAGES DISADVANTAGES1.Able to control from other place and remote control.

2.Able to to off the circuit when breakdown.

3.As a protection device when overload and short circuit occurred.

4.Able to control High current of the motor .

1.Expensive for domestic installation.

CONTACTOR SYMBOLCONTACTOR SYMBOL

Normally Open Normally closed

THERMAL THERMAL OVERLOAD RELAYOVERLOAD RELAY

It’s a protection devices to avoid any damage at the motor .

There are usually broken at the motor. :

- Short circuit.

- wrong connectionThermal Overload is protection devices to

protect overload at the motor.Series connection to the motor.Current are flowing through Thermal

Overload Relay to the motor.

FIGURE OF THERMAL OVERLOAD RELAY FIGURE OF THERMAL OVERLOAD RELAY ( NORMAL CONDITION )( NORMAL CONDITION )

FIGURE OF THERMAL OVERLOAD RELAY FIGURE OF THERMAL OVERLOAD RELAY ( OVERLOAD CONDITION )( OVERLOAD CONDITION )

THR SYMBOLTHR SYMBOLNormally Open Normally closed

COMBINATION SYMBOL

Operation Concept Operation Concept (Overload relay)(Overload relay)

Every THR are completed with potential current rating. Chosing Range should be suitable with full load current of

the motor. THR setting value is 125% of full load current of the

motor.

THR Example calculationTHR Example calculation

Question

A three phase motor are connected to 415V, rating horse power is 3.3 hp and 50 hz with 0.8 power factor. Determine setting value of current to protect the motor.

AnswerAnswer

P = 3 x VI cos ( Pin formula ) IL = P

3 x VL cos IL = 3 x 746

3 x 415 x 0.8

= 3.89 Amp

I setting = 1.25 x 3.89

So setting value is = 4.86 Amp

DIRECT ON LINE STARTERDIRECT ON LINE STARTER Call as a D.O.L starter. This starter are commanly use for small rating

power of the motor.( 0.373kw t0 3.73kW or in hp ½ h.p hingga 3 h.p )

Component part in this starter circuit can be change but should be in series connection each component.

Starting current motor are used for this starter is 6 to 8 time of running current or full load current.

If the full load current for one motor is 8A.So starting current of the motor is between 48A to 64A.

Usually this starter are used for the air-condition,Vaqum and etc.

The limit of load is 3.0 hp.More then 3.0 hp are not suitable.

Total load are cannot exceed 6 to 8 of running current because it will disturb supply source to others load.

But at power plant it this starter are used for the biggest motor horse power such as 100k and above.

That is because power plant are generated the source and not disturb supply source to others load

Advantages and Disadvantages of D.O.L Advantages and Disadvantages of D.O.L StarterStarter

Advantages Disadvantages

1. High starting torque and shortly time to maximum speed.

2. Simple characteristic and for maintenance and also cheapest price.

1. High starting current.Will disturb other system.

2. Need more protection devices for safety.

3. Not sensitive /action.

D.O.L STARTER Control CircuitD.O.L STARTER Control Circuit

Supply

Stop Button

NO auxiliary contact

Start Button Coil

Thermal Overload Relay

C

Neutral

Figure 1

Stop ButtonNO auxiliary contact

Start Button Coil

Thermal Overload Relay

SupplyNeutral

C

Figure 2

Figure 3

Neutral

Stop ButtonNO auxiliary contact

Start Button

Coil

Thermal Overload Relay

Supply

C

Figure 4

supply NeutralStart Button

NO auxiliary contact

Stop ButtonS6

S7

S5

CoilTHR S1 S2 S3 S4

C

D.O.L Starter Main CircuitD.O.L Starter Main Circuit

Three Phase Supply

R Y B

C

M

THR

3 Phase Motor

Contactor Coil

STAR DELTA STARTERSTAR DELTA STARTER

Consist 4 types of Star Delta starter with additional

i. Star Delta Starter without resistance

ii. Star Delta Starter without resistance

( Forward Reverse Operation )

iii. Star Delta starter with resistance

iv. Star Delta starter with resistance

(Forward Reverse Operation )

Additional accessories include limit switch,floot switch,relay and etc.

Motor will operated in start connection at a few second.After that motor will operated in delta connection.

Current in start connection is 58% or 1/ 3 from starting current.

Follow IEE regulation this starter are suitable for 10hp of the motor.

START----------------------------STAR

OPERATION TIME----- DELTA

Current In Star = 58% x ( 6 to 8 x Running current )

Commanly use for :i. Motor Valveii. Electrical Pumpiii. Converyor belt iv. Air-Condition System

For Star Delta with resistance,the resistance/rotor are connected to Delta connection part.

It’s function is to reduce current value when it change to the delta connection/operation.

Advantages of this starter is , It can reduce jerking to the motor when it change to delta operation

Advantages and Disadvantages of Star Delta Starter :

Advantages Disadvantages

i. Can On and off every time.

ii.Simple Maintenance/rarely maintenance compared to auto-trans starter

iii.Low cost for commisioning

i. Limit for use.Only 3 hp to 10hp.

ii. Difficult to wiring.

iii.Easy to burn the motor if wrong connection.

STAR DELTA CONTROL CIRCUITSTAR DELTA CONTROL CIRCUITN

MCB 6A

THR

ON OFF

LC

TDR DC

TDR

SP

TDR

LC

SP

G

DC

R

L

LC

DC

SP

DC

O/L

STAR DELTA MAIN CIRCUITSTAR DELTA MAIN CIRCUITL1 L2 L3

3 Phase Induction Motor

S

A1

M

O/L

DM D D S S

B1

C1

B2 C2 A2

A1

B2

C2

B1

C1

A2

(main switch)

(main fius )

( 3 Phase Supply )

O/L O/L

M

Star point

AUTO TRANSFORMER STARTERAUTO TRANSFORMER STARTER

It’s Special starter in market. It’s can reduce and limit the voltage at the

motor when starting. The voltage connection to the coil can be

limit to anything percent when there are connected in star connection.

During starting ,auto-transformer are in low limit at main winding that are connected to the source and secondary winding are connected to the statorbcoil.

So,it’s can assist to reduce voltage during starting and current are stay at 70% of auto-transformer step.

That is only 70% of full load voltage to the motor when the current are reducing to suitable value current rating.

In this situation we must allert to auto-transformer because it must in star connection and no in open circuit connection.

If open circuit, high voltage are done at auto-transformer and it’s very dangerous.

Then,motor are operated without auto-transformer by using automatic controller.

Normally,this starter are use for motor 3hp to 10 hp

 

The types of Auto-tranformer are commonly is single phase or three phase.

By using this starter ,auto-transformer can step up or down the voltage depend on the load of motor.

This starter are used for any starting torque regulating regulating for the three phase motor are moving different potential load.

The starting torque regulation can be reduce the voltage to the motor.

By using the step level ,this starter are suitable to move the load .

So ,with this way the current are reduce during starting and it’s safety with rating of the load.

When the rotation of the motor are 70% until full load,auto-transformer will disconnected automatically so the motor operated with full voltage supply.

Normally ,the rating step of auto-transformer is 40 %, 60 % and 75 % of line voltage.

Advantage and Disadvantages of Auto-Trans Advantage and Disadvantages of Auto-Trans StarterStarter

Advantages Disadvantages

i. Flexible rating step inside.

ii. Suitable for different load of motor.

ii. Less power losses at accessories device.

i. Sometimes,voltage

disturbing occurred because

no neutral line in circuit.

ii. High voltage occurred when

open circuit in star

connection at

Continue…Continue…

Advantages Disadvantages

i. Suitable for both connection

of the motor.,delta or star

connection.

ii. Only 3 or 4 Terminal

connection of the motor,

not 6 or 7 connection wire

such as star delta starter.

i. High Cost spend for Auto-

transformer.

ii. Thre are not maximum torque

during starting.

So,Not suitable for motor are

need high starting torque during

starting.

iii. Limit for medium

level of motor

AUTO-TRANSFORMER CONTROL CIRCUITAUTO-TRANSFORMER CONTROL CIRCUIT

Fuse

O/L

OFF

ON S

R1

M

S

S MT

M

TR

S

M

S

M

M

L1 L2

R2

N

AUTO-TRANSFORMER MAIN CIRCUITAUTO-TRANSFORMER MAIN CIRCUITL1 L2 L3

M

T

S

AUTO TRANSFORMER

FUSE/ MCB

Thermal Overload Relay

3 Phase Motor

U V W

U2

V2

W2

U1 V1 W1

U3 V3 W3

AUTO-TRANSFORMER MAIN CIRCUITAUTO-TRANSFORMER MAIN CIRCUIT

3 phase mcb / MCCBMCB MCBMCB

AUTO-TRANS

LC

TC

SP

THR

MOTOR

R Y B 3 phase supply

3 phase induction motor

Penghidup Motor Rintangan RotorPenghidup Motor Rintangan Rotor Penghidup ini juga dipanggil penghidup motor rotor

berperintang. Ia hanya digunakan untuk motor jenis rotor berlilit

(Slip ring). Pada asasnya bahagian stator disambung terus

kepada penghidup talian terus sementara bahagian rotornya disambung melalui gelang gelincir ke alat rintangan.

Apabila motor dihidup rintangan rotor berada pada nilai maksima.

rintangan ini akan akan mengurangkan arus mula di rotor secara beransur ansur

Penurunan nilainya adalah selaras dengan pertambahan kelajuan sahingga apabila motor mencapai kelajuan maksima dan ketiga tiga lilitan dilitar pintaskan.

Ia biasanya digunakan di rumah pam, pemampat udara, sistem hawa dingin (kerja berat) dan sebagainya.

Iaitu motor-motor yang terdiri lebih daripada 25 k.k . Mengikut peraturan Elektrik ( Bekalan Lembaga )

1949, Penghidup secara rotor berperintang boleh digunakan untuk motor-motor melebihi 25 k.k.

Bagi penghidup secara rotor berperintang,ia perlu menggunakan perintang yang sesuai dan dilengkapi dengan pelepas tiada- voltan.

Fungsi perintang di rotor ialah untuk mengurangkan arus mula di rotor.

Ia juga boleh digunakan untuk mengawal kelajuan motor.

Kebaikan penghidup rintangan motorKebaikan penghidup rintangan motor

i. Sesuai untuk kerja yang memerlukan daya kilas yang tinggi semasa menghidup.

ii. Gelung stator memperolehi voltan bekalan dengan sepenuhnya.

iii. Sesuai untuk motor-motor yang disambungkan secara bintang atau delta distator.

Keburukan penghidup rintangan motorKeburukan penghidup rintangan motor

i. Ianya terhad kepada motor jenis rotor berlilitan

ii. Memerlukan penyelengaraan tambahan.

iii. Banyak kehilangan kuasa di motor.

Gambarajah Litar Kawalan Penghidup Motor Rotor Gambarajah Litar Kawalan Penghidup Motor Rotor Berperintang.Berperintang.

C1C1

TDR 1

C2

TDR 2

C3

RUNNING LIGHT

LAMPU PENUNJUKBEBAN LAMPAU

C2

TDR1

TDR2

C3

C2

C1

PB ‘OFF’ PB ‘ON’O/L

NO

NC

MCB 6A

Gambarajah Litar Utama Penghidup Motor Gambarajah Litar Utama Penghidup Motor Rotor Berperintang.Rotor Berperintang.

MCB

C1

O/L

C2

C3PERINTANG PERINGKAT 2

PERINTANG PERINGKAT 1

S1 S3S2

E3 D3F3

D1E1F1

Bekalan 3 fasa

Penghidup Motor 3 fasa kawalan Penghidup Motor 3 fasa kawalan Hadapan dan belakangHadapan dan belakang

Sepertimana kita tahu bahawa motor aruhan 3 fasa boleh diputarkan samada dalam putaran ikut jam atau lawan jam.

Untuk menyongsangkan arah putaran motor adalah dengan cara menukarkan turutan fasa bekalan masukan seperti:

Untuk meyongsang arah putarannya kita memerlukan penghidup dengan kawalan suis kendalian tangan atau secara automatik.

Ini adalah kerana motor 3 fasa yang mempunyai kadaran kuasa ½ k.k atau lebih memerlukan penghidup untuk menggerakkan nya.

RYB = RBY

Berikut adalah diantara jenis-jenis penghidup dengan kawalan kehadapan dan kebelakan / mara –songsang :

i. Penghidup Talian Terus mara songsang.

ii. Penghidup Bintang Delta mara songsang.

iii. Penghidup Alatubah-Auto mara songsang.

iv. Penghidup rotor berperintang mara songsang.

Penghidup Talian Terus mara-songsang.Penghidup Talian Terus mara-songsang.

Litar Kawalan dan litar utama Penghidup

R

R Y BPB3

PB1 PB2

F

FR

M

F R

Fius/ MCBFius

Suis UtamaF R

O / L

Bekalan 3 fasa

Contactor yang digunakan adalah jenis 415 Volt

Note:

PB1 : Mara

PB2 : SongsangO/L

Penghidup Bintang-Delta Mara songsangPenghidup Bintang-Delta Mara songsang

Note:

PB1 : Mara.

PB2 : Songsang

Litar kawalan.

STOP

PB1

PB2

LAMPU TRIP

FO / LMCB F

F

RR

R

D

T

S

D

ST

R

D

T

S

FL

N

Contactor yang digunakan adalahjenis 240 Volt

Litar UtamaLitar Utama

Ke litar kawalan

R Y B

F F F R R R

A1 B1 C1

A1 B1 C1

S

B2

C2A2

A2 B2C2

MOTOR

Beban lampau

3 phase MCB / MCCB