Don Klipstein wrote:
In ,
windcrest wrote in part:

On Jul 7, 7:24 am, cj wrote:
i had my transformer in my heil furnace replaced last winter and the new
one hums rather loudly...is that a sign of a problem?also, does that
mean that the transformer is using electricity even if the furnace is
not running?
There are a couple of other reasons a transformer will hum besides DC/
interference on the line or loose laminations/windings.

If a transformer was designed for 50Hz and you are using it in the US
at 60Hz it will hum, maybe the guy put on the wrong transformer.

Actually, transformers designed for 50 Hz work better at 60 Hz than at
50. But if this transformer was made for 120 volts, I give low chances it
was designed for 50 Hz, since line voltage is 230 volts where the line
frequency is 50 Hz (such as Europe and Australia).

60 Hz transformers used at 50 Hz with full rated voltage, on the other
hand, will have their cores pushed closer to or more into saturation than
intended, and will get hotter than intended and usually hum in the
process.

Snip mostly comments on other possibilities such as the transformer being
a cheapie

- Don Klipstein )

Like the capacitors, it probably came from China.

TDD