I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks

Your options are :
a) Get a 110/220V transformer (not cheap)
b) Run a 220V line for this purpose. Your house will likely have 220V
capability. The normal 110V feed is two separate phase 110V line. You get
220V by having a breaker join both lines.
c) Get rid of the 220V units and replace with 110V units.

If you run the present fans on 110V they will burn out. The motor is
designed for a certain wattage. Watts = Amps x Volts. If the Voltage is
half design, the Amps will be twice design and normally burns out the motor,
typically very fast and "energetic".

Dave Paine.

wrote in message
oups.com...
I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks

wrote:
I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks

Probably not, although they should work fine on 220V house current.

Look around for a 50-100W transformer built for overseas appliances. The
fans don't take much power.
Any transformer with a 120/240 primary can also be used, if big enough.
There are lots of these in industrial control systems. How good a scrounger
are you? to use the dual voltage primary, feed 120 into one end and the 120
tap. Take 240 from the same end and the 240V tap. Leave the secondary
open.
Wilson
wrote in message
oups.com...
I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks

Cheaper to buy a 120 V. fan than do all the conversions/wiring.
Bugs

On 21 Jan 2006 07:01:21 -0800, wrote:

The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Make an auto-transformer to step up 110V to 230V. This needs a large
transformer (three times the total fan rating) with a primary winding
that's centre-tapped for 0-110V-230V. These are common in European
electrical equipment from the '50s to the '80s - not sure how easy
they'd be to find in the US.

Then feed your 10V current in on the 0-110V tappings and take a fan
supply from the 0-230V tappings. Ignore the secondary (leave it
unconnected). Place this inside the fan cabinet, earth as appropriate
and insulate/label all the 230V side as if they're all "hot" (i.e. don't
rely on anything being neutral or at low potential)

I'd expect these to make a usable air filter that's very quiet, but
maybe a bit underpowered. I wouldn't expect them to work for a
downdraught sanding table.

If you run the present fans on 110V they will burn out. The motor is
designed for a certain wattage. Watts = Amps x Volts. If the Voltage is
half design, the Amps will be twice design and normally burns out the motor,
typically very fast and "energetic".

Running at half voltage will not double the current consumption, it
will basically halve it, resulting in about 1/4 of the rated power.

A motor has a particular impedance seen "looking" into its cables.
This has nothing to do with the voltage you apply, but rather is a
function of the coils inside the motor. The motor isn't some magical
piece of machinery which draws constant power (wattage). It follows
Ohm's law: V=I*Z, where Z is the impedance. If you solve this
algebraically for the current I, you get I=V/Z. Since Z doesn't
change, the current drawn is directly proportional to the voltage
applied. Hence, half the voltage results in half the current.

I suppose I need to add an asterisk to this comment because motors are
somewhat unique. The impedance of the motor is dynamic; it gets much
higher as the motor spins up, because the mechanical motion of the
motor acts as a generator, essentially creating its own current to some
extent (usually called back-EMF). That's why motors draw a lot more
current upon startup and when they are heavily bogged down than when
they are running at full speed. Thus, since a motor running at half
voltage is likely going to be spinning more slowly than one at the full
rated voltage, it's dynamic impedance will be somewhat lower and it may
draw somewhat more than half the current, but definitely NOT twice the
current.

At any rate, I still agree with Tyke's conclusion - don't do it.

One way you could possibly get luckly: If you have more than one 110V
circuit in your shop, two of them may be on different legs. In that
case, you could run two plugs from two outlets over to your table and
use the hot (black) wires from each to form the two legs of the 220V
circuit. You could just wirenut the neutrals together. This may
violate your electrical code, though.

"Josh" writes:

If you run the present fans on 110V they will burn out. The motor is

[...]


At any rate, I still agree with Tyke's conclusion - don't do it.

On the other hand: Fan motors are sometimes made slower by putting a
transformer in, sometimes even biggish (several kW) three-phase fan
motors are slowd by adjustable three phase transformers. (Seen that
once when a cooling fan of that type used to cool some delicate
electronics blew so much air that the airflow made the electronics
boards vibrate too much, so the fan had to be slowed down, and an
electronic dimmer was out of the question because of the
electromagnetic noise it would produce...)
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23

Look around for a 50-100W transformer built for overseas appliances. The
fans don't take much power.
Any transformer with a 120/240 primary can also be used, if big enough.
There are lots of these in industrial control systems. How good a scrounger
are you? to use the dual voltage primary, feed 120 into one end and the 120
tap. Take 240 from the same end and the 240V tap. Leave the secondary
open.
Wilson

wrote in message
oups.com...
I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks

Those things work by changing the phase angle between the voltage and
current. The voltage itself is not reduced.

Really though anything that the OP tries will cost a lot.
Jim
"Juergen Hannappel" wrote in message
...
"Josh" writes:

If you run the present fans on 110V they will burn out. The motor is

[...]


At any rate, I still agree with Tyke's conclusion - don't do it.

On the other hand: Fan motors are sometimes made slower by putting a
transformer in, sometimes even biggish (several kW) three-phase fan
motors are slowd by adjustable three phase transformers. (Seen that
once when a cooling fan of that type used to cool some delicate
electronics blew so much air that the airflow made the electronics
boards vibrate too much, so the fan had to be slowed down, and an
electronic dimmer was out of the question because of the
electromagnetic noise it would produce...)
--
Dr. Juergen Hannappel http://lisa2.physik.uni-bonn.de/~hannappe
Phone: +49 228 73 2447 FAX ... 7869
Physikalisches Institut der Uni Bonn Nussallee 12, D-53115 Bonn, Germany
CERN: Phone: +412276 76461 Fax: ..77930 Bat. 892-R-A13 CH-1211 Geneve 23

On Sat, 21 Jan 2006 10:25:19 -0500, "Tyke" wrote:

Your options are :
a) Get a 110/220V transformer (not cheap)
b) Run a 220V line for this purpose. Your house will likely have 220V
capability. The normal 110V feed is two separate phase 110V line. You get
220V by having a breaker join both lines.
c) Get rid of the 220V units and replace with 110V units.

If you run the present fans on 110V they will burn out. The motor is
designed for a certain wattage. Watts = Amps x Volts. If the Voltage is
half design, the Amps will be twice design and normally burns out the motor,
typically very fast and "energetic".

Dave Paine.

wrote in message
roups.com...
I have six electric fans that were salvaged from an old computer
equipment cabinet (not a PC, but data center size equipment). I'd like
to repurpose them for either a downdraft cabinet or air filtration
system. The label states that they are 230V. Is there any possibility
of running them on standard 110V house current?

Thanks


If the fans are the square "muffin" or "boxer" type fans you might be
able to successfully run them off of 110v. Years ago we would
scavenge these type fans for use in cooling the home brew stereo amps
we constructed. Running them at 110v made them run at 1/2 speed which
would move some air but would not add any significant unwanted noise
if implemented carefully. We never had a problem with them
overheating that I am aware of, they were supposed to be internally
thermally protected, but we never had any shut down or do nay thin
else out of the ordinary.

It seems to me that even now that the ac powered fans are more
effective than the PC's 12v howling monsters. I found a reasonably
good source of both 110v and 220v ac fans at surpluscenter.com. I
always use them with an add-on fan filter mounted so it can easily be
changed/cleaned without having to disassemble whatever you are using
them for. I have used them for everything from replacement/upgrade
for commercial refrigeration condenser units to embedded cooling
inside built-in home theater systems. good luck, regards, Joe.

Thanks all for the info. The fans I have are 10" diameter round
aluminum case fans made by Nidec Torin. They are no longer made.
According to the manufacturer, they each have an airflow of 530 CFM.
The motors are thermally protected and are abll bearing type. If I had
230V power easily available, I think they would be quite useful. Maybe
I'll Ebay them.