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?

thanks, cj

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?

thanks, cj

Some things you can try:

If its mounted on a steel J box try rotating the transformer 90
degrees.

Is there anything else on that branch circuit like a refrigerator that
could be inducing interference onto the powerline? This can cause a
transformer to hum more. Your furnace should be on a dedicated
breaker. Some applicances can also leak a little DC on the powerline,
wreaking havoc with transformers.

It could simply be a cheapo transformer. Good transformers are wound
tightly, the laminations use high quality glue and they are potted in
epoxy. Cheap transformers may not even be potted and will always hum
more.

Check for a simple mechanical looseness somewhere on the J box.

If all else fails, get a high quality transformer, they are simple to
replace. I suspect its just a cheap unpotted transformer or loose
lamination on the core.

Yes, it is pulling a small amount of current all the time, but that
current varies with the load on the secondary.

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?

thanks, cj

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.

If the transformer is underrated for the load it will hum more (and
also heat up and fail early) in this case up the rating of the
transformer. Maybe he was cutting corners by using a transformer that
was rated under or just at the load level, the cost of a transformer
is proportional to its current rating with all other factors the same.

If your mains voltage is too high the transformer will hum more, you
cant do anything about this, but a high quality transformer will
handle it better.

A poorly designed transformer with high magnetic field levels will hum
more, again this is probably your problem, a cheap-ass transformer.

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?

thanks, cj

See if you can dribble, pour or squirt some quick setting epoxy
onto/into it. (With the power to it off of course).

That's worked for me more than once.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10e12 furlongs per fortnight.

On Jul 7, 3:29*pm, wrote:
On Tue, 07 Jul 2009 08:24:47 -0400, 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?

thanks, cj

You should have had the repair guy come back right away and replace
it. *Most likely the core or windings are loose. *It will work just
fine, it will just annoy you forever. *Yes, they do use power all the
time. *In summer, shut off the furnace switch.

I recall once hitting a transformer with a hammer to bang the
laminations together and also IIRC correctly, squeezing one in a vise.
To also tighten the laminations.
Another idea might be to loosen (yes loosen) the bolts holding it down
to whatever is amplifying the sound and/or slipping some bits of
rubber under the edges!

On Jul 7, 2:57*pm, stan wrote:
On Jul 7, 3:29*pm, wrote:

On Tue, 07 Jul 2009 08:24:47 -0400, 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?

thanks, cj

You should have had the repair guy come back right away and replace
it. *Most likely the core or windings are loose. *It will work just
fine, it will just annoy you forever. *Yes, they do use power all the
time. *In summer, shut off the furnace switch.

I recall once hitting a transformer with a hammer to bang the
laminations together and also IIRC correctly, squeezing one in a vise.
To also tighten the laminations.
Another idea might be to loosen (yes loosen) the bolts holding it down
to whatever is amplifying the sound and/or slipping some bits of
rubber under the edges!

You got lucky. The laminations are in the core iron, and the windings
completely wrap the core, laminating core iron gives a transformer a
much higher saturation point than a solid iron core (the laminations
are glued). Hitting with a hammer is more likely to just short the
winding by chipping the enamel off the wire someplace because the coil
wire will get hit and core untouched.

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 )

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

On Tue, 7 Jul 2009 08:02:42 -0700 (PDT), windcrest
wrote:

On Jul 7, 7:24Â*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?

thanks, cj

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.

If the transformer is underrated for the load it will hum more (and
also heat up and fail early) in this case up the rating of the
transformer. Maybe he was cutting corners by using a transformer that
was rated under or just at the load level, the cost of a transformer
is proportional to its current rating with all other factors the same.

If your mains voltage is too high the transformer will hum more, you
cant do anything about this, but a high quality transformer will
handle it better.

A poorly designed transformer with high magnetic field levels will hum
more, again this is probably your problem, a cheap-ass transformer.

Likely Chinese - or possibly Mexican manufacture - most definitely
"cheap" even if not low cost. ALL transformers hum a little bit - and
all use SOME current even with no load, but the better ones hum less
and use less power.