What does auto transfer mean?

What does auto transfer mean? 
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1 Answer

Answer :

If one of the sources is tripped on main protection its breaker will be tripped and the tie-breaker will close. This transfer of supply from one source to other source is called auto transfer. To restore the class IV whenever the UT or SUT is lost Auto transfer is provided.
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Related questions

What are the conditions for Auto transfer scheme?

Description : What are the conditions for Auto transfer scheme?

Last Answer : Backup protections are not allowed to initiate the Auto transfer. Because under voltage may exist in the bus. Similarly protection in LV of the transformers are not initiating the Auto transfer scheme. There are three metrics used ... in GT. 4. Fault in 220 kV bus (SUT). 5. Fault in SUT (86M).  

What are the types Auto transfer scheme?

Description : What are the types Auto transfer scheme?

Last Answer : 1. Fast transfer scheme to close the tie-breaker in less than 200 milli seconds. This limits transient current and voltage dip in the bus and does quick acceleration of the motors. 2. Slow transfer after 200 milli seconds.  

Why auto transfer is prevented if the backup protection is operated?

Description : Why auto transfer is prevented if the backup protection is operated?  

Last Answer : The back up protection is supposed to operate in case of a bus fault. Hence the auto transfer is prevented. 

Why auto transfer is blocked for back up protection?

Description : Why auto transfer is blocked for back up protection?

Last Answer : Because Backup protection operates normally for bus faults. All main protections are generally operating for internal faults therefore there is no point in restoring the power supply through auto transfer when there is a bus fault existing. 

When auto transfer is effected?

Description : When auto transfer is effected? 

Last Answer : a) When any one module trips b) When overload exceeds 175% for more than 40 msec. is existing. c) When UPS output voltage varies beyond 415v +/- 10% 

An auto transformer is preferred over an ordinary two winding transformer due to: a) Safety of operation b) Availability of taps on secondary c) Copper savings d) All the above

Description : An auto transformer is preferred over an ordinary two winding transformer due to: a) Safety of operation b) Availability of taps on secondary c) Copper savings d) All the above

Last Answer : Ans: C

If Relay #5 changed contact position grounding the 'auto' input to the 'pitch controller module', pitch control would be effected by the _________________. EL-0095 A. pitch feedback potentiometer B. Engine room thrust split potentiometer C. Engine room thrust lever only D. Bridge thrust lever only

Description : If Relay #5 changed contact position grounding the 'auto' input to the 'pitch controller module', pitch control would be effected by the _________________. EL-0095 A. pitch feedback potentiometer B. Engine room thrust split potentiometer C. Engine room thrust lever only D. Bridge thrust lever only

Last Answer : Answer: B

As shown in the two illustrations for 'pitch control' and engine speed control', when the plant is in 'AUTO / CRUISE' propeller pitch is controlled by ___________. EL-0095 A. the 'trim potentiometer' and speed by either 'thrust lever' B. either 'thrust lever' and speed also by the selected Lever C. the split trim potentiometer and speed by its 'trim pot'. D. either 'thrust lever' and speed by the 'trim potentiometer'

Description : As shown in the two illustrations for 'pitch control' and engine speed control', when the plant is in 'AUTO / CRUISE' propeller pitch is controlled by ___________. EL-0095 A. the 'trim potentiometer' and ... and speed by its 'trim pot'. D. either 'thrust lever' and speed by the 'trim potentiometer'

Last Answer : Answer: D

What are the plant conditions existing in the 'engine speed control' diagram shown in the illustration? EL-0096 A. The Bridge is in control in the 'auto. maneuver' mode. B. The Engine Room is in control in the 'cruise split' mode. C. The Bridge is in control in the 'auto. split' mode. D. The Engine Room is in control in the 'auto. maneuver' mode.

Description : What are the plant conditions existing in the 'engine speed control' diagram shown in the illustration? EL-0096 A. The Bridge is in control in the 'auto. maneuver' mode. B. The Engine Room is in control in ... in the 'auto. split' mode. D. The Engine Room is in control in the 'auto. maneuver' mode.

Last Answer : Answer: D

Explain about auto transformer?

Description : Explain about auto transformer?

Last Answer : A. It is type of transformer with only one winding a portion of which is shared by both primary and secondary. Advantages: It is used where transformation ratio differs little from unity. As ... voltage as per out requirements and can smoothly increase or decrease its value as per our requirement.

Why is an auto-transformer not used as a distribution transformer?

Description : Why is an auto-transformer not used as a distribution transformer?

Last Answer : The autotransformer cannot provide isolation between HV and LV side. Due to open circuit in the common portion, the voltage on the load side may shoot up to dangerously high voltage ... voltage on LV side is potentially dangerous. Hence the autotransformer cannot be used as distribution transformer

What are the typical uses of auto transformer ?

Description : What are the typical uses of auto transformer ?

Last Answer : i) As a booster to compensate the voltage drop for better regulation ii)As induction motor starters. iii) In locomotive iv) As furnace transformer

What is Auto-transformer?

Description : What is Auto-transformer?

Last Answer : In these transformer only one winding is used as primary and secondary. Also, primary and secondary are conductively coupled.

What are the protective parameters to changeover AVR auto to manual?

Description : What are the protective parameters to changeover AVR auto to manual? 

Last Answer : a. PT supply fail. b. Auto pulse fail. c. Supply of limiter fail. d. Supply of auto channel fail. e. Regulated supply fail. f. High auto reference. 

What is the difference between an auto reset and manual reset overload relay?

Description : What is the difference between an auto reset and manual reset overload relay?

Last Answer : a. Auto reset relay closes its contacts when the bimetallic strip gets cooled. In manual reset relay we have to manually reset the relay because even though bimetallic strip cools its contacts are not ... . Manual over load relay is reseted by pushing the reset button provided on the MCC cell. 

Transient stability can be improved by a) By putting series capacitor b) By using dynamic resister c) Auto re-closers d) All of the above

Description : Transient stability can be improved by a) By putting series capacitor b) By using dynamic resister c) Auto re-closers d) All of the above

Last Answer : Ans: All of the above