Loading A Transformer

Status
Not open for further replies.
M

magdumshirish

Member
Sir,
I Have A 315 Kva Transformer.

Voltage Ratio 11kv/433v

Rated Sec Current 420amp

I Have A Continious Current Of 17o Amp.

Can I Start 5o Hp Motor At This Status
 
315 Kva

315 Kva

IMHO,
and I am not an electrician,
from this post and your previous ones,
it sounds to me like you are,
to use an idiom,

"in over your head."

These electrons can sometimes play for keeps.
 
the information you provided is somewhat sketchy

depends on what type starter, if I understand your post, its borderline. you could, however, buy a 50 hp motor that would most likely work.
 
Loading A Transformer

Respected Sir,
Thanks For Reply And Excuse Me For A
Questions. Sir, I Want To Understand If Ror Example
My Steady Load Current Is 170 Amps, And I Want To
Switch On A Induction Motor Seafly What Maximum
Hp Motor I Can Start.
If 420amp Is Fl Sec Current, How Much
Inrush Current It Can Sustain And How Much Time.
If I Do So What Simptoms I May Come Accross
Like Flicring.
 
Like others have said, for us to give an exact motor size there is much more information needed.

Voltage flicker is largely dependent on two things:

1) The source impedance of the electrical system seen by the load. This includes the impedance from the load all the way to the generating station.

2) The magnitude of the starting current of the load.

Are you only worried about flickering lights, or about negatively affecting other equipment loads?


Putting a soft start would decrease the starting current and help out as would a variable speed drive. But with a drive, you introduce new possible problems such as increased voltage sag and swell sensitivity and harmonics.
 
Light flicker will be dependent on more than just the transformer, primary conductor length, secondary conductor length type of conductors utilized. In an electrical distribution system all components are interrelated to provide the point of use voltage to all utilization equipment.

Most transformer manufactures will have in their literature information regarding start up and motor running for their transformers. I am no engineer (as has been proven on this forum more than once) but I am sure such items and core type, conductor type utilized to wind the transformer will play into this equation also.

Lastly light flicker is person dependent, women are seem to be more prone to noticing flicker. I have been on sites where light flicker was evident but after a few moments unless I waited to notice the flicker I soon no longer paid attention to it.
 
Last edited:
Status
Not open for further replies.
Top