DC Fans - weird problem

R

RR

Guest
I have a good quality on-line Uninterruptible Power Supply with 2 fans.

One of the fans is too noisy, so I'm wanting to replace it.

I've purchased 4 fans, 2 each of 2 different types; Sunon and Dick Smith
Electronics.

None of the new fans will work properly. The Sunon fans wiggle, and will
spin if I set them going with my finger.

The Dick Smith fans won't spin at all.

The original fan (which still works, therefore, the circuit is OK), is:
Minebea Model 3110Gl-B4W-B44
12V DC 0.26A
Brushless

The Sunon fans (which I've now returned to the shop) were 12V DC 0.26W
(probably a misprint and were actually 0.26A)

The Dick Smith fans are model Y8507 and simply say 12 Volt. These are
sleeve bearings.

The voltage measured with a Dick Smith fan connected is about 3V and with
the original Minebea fan connected (and spinning) it's 10.7V.

I'm completely confused.

Any help appreciated.

thanks,
RR
 
"RR" <russrob@hotpop.com> wrote in message
news:Y7d8b.96145$bo1.79596@news-server.bigpond.net.au...
I have a good quality on-line Uninterruptible Power Supply with 2 fans.

One of the fans is too noisy, so I'm wanting to replace it.

I've purchased 4 fans, 2 each of 2 different types; Sunon and Dick Smith
Electronics.

None of the new fans will work properly. The Sunon fans wiggle, and will
spin if I set them going with my finger.

The Dick Smith fans won't spin at all.

The original fan (which still works, therefore, the circuit is OK), is:
Minebea Model 3110Gl-B4W-B44
12V DC 0.26A
Brushless

The Sunon fans (which I've now returned to the shop) were 12V DC 0.26W
(probably a misprint and were actually 0.26A)

The Dick Smith fans are model Y8507 and simply say 12 Volt. These are
sleeve bearings.

The voltage measured with a Dick Smith fan connected is about 3V and with
the original Minebea fan connected (and spinning) it's 10.7V.

I'm completely confused.

Any help appreciated.

thanks,
RR
Click to expand...
try all the 12 volt fans on a 12 volt power supply or car battery (or the
battery in the UPS assuming its 12.6V). if they work the problem is the
source voltage. maybe a flaky resistor or part in series

make sure the fans do not have some kind of whackey diode built into them
which is hooked up backwards.
 
"tim perry" <timperry@nospamers.adelphia.net> wrote in message
news:1ld8b.415$Pd2.348505@news1.news.adelphia.net...
try all the 12 volt fans on a 12 volt power supply or car battery (or the
battery in the UPS assuming its 12.6V). if they work the problem is the
source voltage. maybe a flaky resistor or part in series
Click to expand...
Thanks, they all work fine outside the UPS.

So, it's definitely the source circuit? The UPS has two fans with separate
connectors.
Is it likely that the two connectors would be on the same circuit (which
might be
flaky)?

I guess if they are separate circuits then the same problem wouldn't be on
both connectors.

make sure the fans do not have some kind of whackey diode built into them
which is hooked up backwards.
Click to expand...
Are you suggesting a manufacturing fault in the fans? If so, then it's not
likely with 4 fans from 2 different manufacturers.

thanks again,
RR
 
RR wrote:

I have a good quality on-line Uninterruptible Power Supply with 2 fans.

One of the fans is too noisy, so I'm wanting to replace it.

I've purchased 4 fans, 2 each of 2 different types; Sunon and Dick Smith
Electronics.

None of the new fans will work properly. The Sunon fans wiggle, and will
spin if I set them going with my finger.

The Dick Smith fans won't spin at all.

The original fan (which still works, therefore, the circuit is OK), is:
Minebea Model 3110Gl-B4W-B44
12V DC 0.26A
Brushless

The Sunon fans (which I've now returned to the shop) were 12V DC 0.26W
(probably a misprint and were actually 0.26A)

The Dick Smith fans are model Y8507 and simply say 12 Volt. These are
sleeve bearings.

The voltage measured with a Dick Smith fan connected is about 3V and with
the original Minebea fan connected (and spinning) it's 10.7V.

I'm completely confused.

Any help appreciated.

thanks,
RR
Click to expand...
Are you sure the originals were DC fans and not AC?
 
On Fri, 12 Sep 2003 05:49:44 GMT "RR" <russrob@hotpop.com> wrote in
Message id: <Y7d8b.96145$bo1.79596@news-server.bigpond.net.au>:

None of the new fans will work properly. The Sunon fans wiggle, and will
spin if I set them going with my finger.

The Dick Smith fans won't spin at all.
Click to expand...
Did you try reversing the leads?
 
The biggest problem I have with fans is the lubricant is not
permanent.

remove the label and drop one drop of oil on the shaft. The old one
will run for another year - usually.
 
The point of a UPS is to improve reliability. Why leave something in
that
you know will fail, and will require you to shut down the system and
solve
the problem again?

Cher wrote:

The biggest problem I have with fans is the lubricant is not
permanent.

remove the label and drop one drop of oil on the shaft. The old one
will run for another year - usually.
Click to expand...
 
"RR" <russrob@hotpop.com> schreef in bericht
news:UGd8b.96178$bo1.82475@news-server.bigpond.net.au...
I guess if they are separate circuits then the same problem wouldn't be on
both connectors.
Click to expand...
Just a guess, maybe the 2 fans are in series connected to a 24 supply? I
would never design it like that, but never know in this crazy world.

Al
 
"CJT" <cheljuba@prodigy.net> wrote in message
news:3F6170C0.70404@prodigy.net...
Are you sure the originals were DC fans and not AC?
Click to expand...
The label says DC and my multimeter reads the DC on the lines.

thanks,
RR
 
"JW" <none@dev.nul> wrote in message
news:cub3mv4vh0qjpipbq92b021j37qf98gm9q@4ax.com...
On Fri, 12 Sep 2003 05:49:44 GMT "RR" <russrob@hotpop.com> wrote in
Message id: <Y7d8b.96145$bo1.79596@news-server.bigpond.net.au>:

None of the new fans will work properly. The Sunon fans wiggle, and will
spin if I set them going with my finger.

The Dick Smith fans won't spin at all.

Did you try reversing the leads?
Click to expand...
Yes, that didn't help either.

thanks,
RR
 
"Cher" <ccher@your.place> wrote in message
news:9ol3mvk580bspu09vgdtmnrcbn0oodinhq@4ax.com...
The biggest problem I have with fans is the lubricant is not
permanent.

remove the label and drop one drop of oil on the shaft. The old one
will run for another year - usually.
Click to expand...
Good idea. But since it is on its way out, I'd prefer to replace it.

A colleague who knows more about electronics than I thought that the UPS
circuitry might be using current/voltage to control the speed of the fans.
Therefore, only specific types of fans will work.

However, when I called Farnell Components, their tech guy had never heard of
that on a two wire system.

thanks,
RR
 
I suspect a speed regulator circuit for the fans because you measure 10.7V
on the working fan (not 12V). Try another brushless fan, or lubricate a
little the shaft of the old fan as it's suggested. I suspect the new fans
haven't worked properly because of different features. It's better to get a
lower amperage fan (e.g. 0.2A). You can also try to determine the old motor
features form here
http://www.minebea-ele.com/en/product/motor/F_4000/index.html (dowload the
pdfs and see which motor is used for the fan).

--

Yianni
in@9mailbox.gr (remove number nine to reply)

--
"RR" <russrob@hotpop.com> wrote in message
news:LTr8b.97485$bo1.22203@news-server.bigpond.net.au...
"Cher" <ccher@your.place> wrote in message
news:9ol3mvk580bspu09vgdtmnrcbn0oodinhq@4ax.com...
The biggest problem I have with fans is the lubricant is not
permanent.

remove the label and drop one drop of oil on the shaft. The old one
will run for another year - usually.

Good idea. But since it is on its way out, I'd prefer to replace it.

A colleague who knows more about electronics than I thought that the UPS
circuitry might be using current/voltage to control the speed of the fans.
Therefore, only specific types of fans will work.

However, when I called Farnell Components, their tech guy had never heard
of
that on a two wire system.

thanks,
RR
Click to expand...
 
On Fri, 12 Sep 2003 22:31:04 +0200, "The Al Bundy"
<the_al_bundy@*^no-spam!^*hotmail.com> wrote:

"RR" <russrob@hotpop.com> schreef in bericht
news:UGd8b.96178$bo1.82475@news-server.bigpond.net.au...

I guess if they are separate circuits then the same problem wouldn't be on
both connectors.


Just a guess, maybe the 2 fans are in series connected to a 24 supply? I
would never design it like that, but never know in this crazy world.
Click to expand...

I've run into a few setups that put fans in series. I suspect this is
very likely if the UPS has a pair of 12volt batteries in series. The
bad fan would try to draw more current and hence get less voltage.

Does the other fan run with the first disconnected? What's it's
voltage look lke?
 
OK, just trying to give you some field expedience. If you don't want
to do it twice - and I have seen oiled fans last longer than a new one
- More than likely the fan connector is protected by a current limit
resistor. That means the more current you draw the less voltage you
get. A dead short on the pins should not cause burnt traces on the
board. The downside is that a fan with a higher current draw will be
trying to run on less voltage to the point that it may not function at
all or may only function if you start it first - max current drain. If
you have a few assorted resistors you can use them to determine a
usable current rating for the fan using a little Ohm's law. Or just
get another fan with the same rating as the old one.

On Fri, 12 Sep 2003 22:36:27 GMT, "RR" <russrob@hotpop.com> wrote:

"Cher" <ccher@your.place> wrote in message
news:9ol3mvk580bspu09vgdtmnrcbn0oodinhq@4ax.com...
The biggest problem I have with fans is the lubricant is not
permanent.

remove the label and drop one drop of oil on the shaft. The old one
will run for another year - usually.

Good idea. But since it is on its way out, I'd prefer to replace it.

A colleague who knows more about electronics than I thought that the UPS
circuitry might be using current/voltage to control the speed of the fans.
Therefore, only specific types of fans will work.

However, when I called Farnell Components, their tech guy had never heard of
that on a two wire system.

thanks,
RR
Click to expand...
 
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