Monday, April 14, 2014

Direct online Applications Reverse Forward, Limit & Level Switch, Remote Starters


Earlier we discussed about Direct Online Starter Basic Circuit.

For Basic Circuit diagram of Direct online visit at link below:-

http://electrialstandards.blogspot.in/2014/04/direct-online-dol-starter.html

Now let’s discuss about Direct online Starters following circuits:-

1.       Reverse forward direct online Starter.
2.       Limit Switch & level Switch circuit in DOL.
3.       Remote Start/Stop Direct online Starter Circuit.






Let’s discuss their circuitry one by one:-
1.     Reverse Forward Direct Online Starter:-
Power and control circuit for Reverse forward Direct online starter is as below:-




DOL Reverse Forward Circuit; DOL Applications

Reverse forward DOL




In control circuit C1 contactor is used as forward contactor and C2 contactor is used as Reverse contactor
And also Reverse contactor NC is used in series with Forward contactor starting and also forward contactor NC is used in circuit of Reverse contactor so that while motor is operating in one direction it’s other direction contactor could not hold, Which otherwise leads to Short circuit.
Reverse forward applications for DOL starter are used boilers and other applications in an Industry.

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2.       Limit Switch & level Switch circuit in DOL:-
        This type of application is used for houses for water level controllers and Limit switches are used in industries for switching off the motor when limit is reached. This type is used in Air compressors, gas compressors etc. where at a certain pressure limit motor get switched off. 
Circuit for the same is as given below:-

DOL Circuit with Limit Switch; DOL Level Switch Circuit

3. Remote Start/Stop Direct online Starter Circuit:-

Remote Start/Stop Direct online circuit is as below:-
DOL Starter with Remote Circuit
For taking 3 wires are taken from starter to remote.
1 wire for stop, 1 for start and 1 as common.
These applications are used where there is need for starting and stopping the motor near operator.