Does the Frequency changed in Transformer's secondary?

[aljamri]

Hi everybody,

Our mains is 220v 50Hz, I'll be using step down transformer to make 220v from mains to 110v. and I need to use cooling fan with 110v ac with no Frequency mentioned. Do I have to worry about the Frequency or not ?

Thank you for all.

 

[Mehtab Ali Zahid]

the transformer only steps up or down the voltage, it does not change frequency. the frequency at input and output is same

 

[bailey45]

A transformer does not change the frequency of the power supplied, however, frequency does effect how some motors will operate. If your fan motor is an induction type motor it may not operate correctly if you supply a frequency other than the required value. 60 Hz induction motors operate slower on 50Hz.

 

[crutschow]

A motor designed for 60Hz may draw excessive current if operated at 50Hz. So you need a fan rated for 50Hz.

 

[Nigel Goodwin]

A motor designed for 60Hz may draw excessive current if operated at 50Hz. So you need a fan rated for 50Hz.

Generally it makes no difference at all - such concerns are purely theoretical, and assume that the motor is badly designed (already under too much stress at even 60Hz).

 

[crutschow]

Generally it makes no difference at all - such concerns are purely theoretical, and assume that the motor is badly designed (already under too much stress at even 60Hz).

I'm not sure why you say it's purely theoretical. I would think most commercial motors are designed as cheaply as possible with little margin. At a minimum, the motor magnetizing current will increase by the inverse ratio of the two frequencies, and that will certainly increase the power losses and motor temperature. But perhaps that would typically not be enough to cause motor failure.

 

[szhighstar]

normally when we design a lamination transformer( low frequency), we consider 50Hz and 60Hz, we also test output voltage and exciting current at two frequencies, so that transformer can be applied on 50Hz and 60Hz, I do not know how to comment your motor, however you should be confirm your desgin about transformer, e.g. power requested and diameter of wire.