What is the d/f between DOL & star delta starter & automatic
star delta starter?
Answer Posted / romil verma
When the motor is connected in Delta and started by DOL method, the voltage applied across a coil is the voltage between two phases i.e, 415V approx. Therefore the current inrush is high. In order to minimize the starting current, voltage across the coils should be brought low, which can be done if we connect the coils in star. During star connection the voltage across a coil is 240V (approx) which is 1/(sq root of 3)times that in delta which results in a simultaneous lowering of current also. This eases the stress on relays and conductors.When the motor attains 90% of its rated speed the coils are connected in Delta. therefore generating higher power.
| Is This Answer Correct ? | 5 Yes | 3 No |
Post New Answer View All Answers
What is meant by celling voltage & current in excitor ?
what are safety measures in /control in diesal engine/ explain them?
We have 90mX100m hangar with 16 no.of supporting pillar. It is required to provide power supply on all pillars. what is suggested earthing scheme for hangars.
Benifits of 3ph 4 wire metering over 3ph 3 wire
What is the difference between AC and DC injection methods for rotor earth fault protection
IF I KNOW THE AREA OF CROSS SECTION OFTHE WIRE , WATTAGE OF THE LOAD ,VOLTAGE SUPPLY WHAT IM GIVING TO THE LOAD AND ALSO POWER FACTOR OF LOAD ....... SO GIVE ME FOR WHAT AMOUNT OF CURRENT I SHOULD USE WHICH TYPE OF CABLE?
A 10 MVA, 66KV, 50Hz, Y-connected 3-phase alternator has synchronous reactance of 0.635 Ù. It is working at full load at 0.8 lagging p.f. condition. Find torque angle, neglect armature resistance.
Why neutral cable carry current.
working function importance of mdc meter
Explain thin film resistors and wire-wound resistors
lenz law application and define
SUTIABLE FOR ohm's law super conductor
what is the principle of the single phase energy meter? and,what is the advantages and disadvantages of single phase energy meter?
what is the difference between rectifier and converter and commudator?
current transformer balance the power level on both sides. e.g in case of step up, at secondary side voltage rise but current decrease and vice versa in case of step down transformer. but how this power level remains same in case of current transformer and voltage transformer