asyscronous motors

7/28/2019 Asyscronous Motors

1/11

(3- , Squirrel Cage Induction Motors)


2/11

STARTING METHODS

Direct OnLine Starters

AutoTransformer

StartersY- Starter Soft Starters

a) FCMAmethod

b) Thyristorcontrolled

method


3/11


4/11

K i l

b u r n

O i l i m m

e r s e

d t y p e

( D O L )

This type starters are available for lower HP motors

Robust construction, and more weight

Overload protection through thermal relays are available

Less reliable

Switching through pure copper knobs

Frequent maintenance required

Knobs operate under oil media

Operation through push button


5/11

Contactor

type DOLSTARTERS

used for the motors ranges up to 5 HP

Overload protection through thermalrelays

More reliable than oil type starters

Less weight, easy maintenance, more

accurate

Different makes are L&T, Telemechanique,ABB, Seimens, CG, BCH etc.,


6/11

Auto

TransformerStarters

These type of startersranges for 50,60, 75, 100,

150 HP etc.,

Auto transformer& knobs are

completely oilimmersed

Very robustconstruction,more weight

Frequentmaintenance

required

Completely Manualoperating

Knobs need to bechange for 3-6

months

Overload protectionthrough dash pot s


7/11

Auto

TransformerStarters

Less reliable

100 % mechanical parts,ageing affect presents

Plunger type novolt coil

Precaution s are tobe followed before

operating the starter

Does not tripproperly under

overload condition,also in the events of

blown fuses, powerfailure

Starter should be

close to the motor

Remote operationnot possible


8/11

Y -

S t a

r t e r

Kilburn dry type Y- Starterup to 20 HP

Kilburn oil immersed Y- Starter

Contactor type Y- Starter


9/11

K i l

b u r n

d r y

t y p e Y -

S t a r t e r

up to 20 HP rangeavailable

Very robustconstruction

Overloadoperation through

dash potsLess reliable

Precautions to befollowed before

switching

100 % mechanicalparts

Switching throughpure copper knobs

Does not tripproperly

Less accurateFrequent

maintenancerequired

Operator shouldbe with metallic

parts


10/11

Kilburn oil immersed Y- Starter

Up to 85 HP range available Very robust construction, lesser weight than auto transformer starters Oil & dirt presents Overload operation through dash pots Less reliable Precautions to be followed before switching 100 % mechanical parts Switching through pure copper knobs Does not trip properly Less accurate Frequent maintenance required

Operator should be with metallic parts Starter should be nearer to the motor Remote operation not possible Automatic 1- sensing not possible


11/11

Contactor type Y- Starter

From 5 HP this type may be used Up to 20 HP semi automatic possible For all rating Fully automatic type Clean & neat

Different ranges & makes available More reliable Automatic 1- sensing possible Starter should not be compelled to place near the motor Remote operation possible

Different ranges should mounted in single panel Overload protection through thermal tripping Switching through silver coated contacts

asyscronous motors

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