Re: [CAD_CAM_EDM_DRO] Re: Transformer question

----- Original Message -----
From: Roman Black <fastvid@...>
To: <CAD_CAM_EDM_DRO@egroups.com>
Sent: Saturday, January 13, 2001 11:06 AM
Subject: [CAD_CAM_EDM_DRO] Re: Transformer question

with some snips

> Sorry to argue, but you can't. A 110v primary
> transformer will blow very badly if connected to 240v.
> Mains transformers are matched to the voltage and
> frequency of the mains AC supply.
You are correct in that the transformer over heat blow the fuse possabibly
arc over internally depending on the overvoltage you apply. A lot depends
on the load you apply to the output.

But the man asked if he connected a 240 to 120 transformer to 110 would he
get 60 out.

He will. The Amp ratings may be changed but the voltage is related to the
ratio of turns.

> The primary needs to have the correct inductance.
> Even going from a 50Hz to 60Hz country can have
> significant effects, not so much with small
> appliance transformers but larger ones will run
> out of spec at the wrong mains frequency.
> -Roman

You are correct going from 60 to 50 Hz. 50 Hz motors and transformers
require more iron in the core because of the lower Hz. They heat up
depending on load.

You can however take a 50 Hz transformer and apply 60 hz. If being run near
the 50 Hz temperature limits it will run cooler on 60 Hz. Voltage in to out
is still related to the turn ratio.

50 Hz motors will run faster on 60Hz but not hotter. Usual just changed a
pulley to correct if necessary. I remember the ladies all thought their
washing machines worked better without changing anything.

I have lived in an area that has had a major hydro electric plant running at
50 Hz until recently.
The Mississippi river dam at Keokuk, IL was built as a 50 Hz plant just
after the turn of the century (1900) and until recently generated power for
some industrial customers in the St. Louis area and to some local area
towns.

During my college days I worked as a movie projectionist at several theaters
that could switch their incoming power from a 60 Hz supplier to a 50 Hz
supplier. Movie equipment was transformered and motored for 50 Hz. The
change to 60 Hz required moving a lever that changed the gear ratio or
actually changing a small gear that drove the film in the projectors.

Why was the hydro plant built 50 Hz you ask. The hydro plant was funded by
Kaiser Welhelm's family of Germany and some German investors. I think all
they did to change to 60 Hz was change the gearing to the governors on the
turbines.

Hugh