need help with fan speed

[jim]

Could someone please help me to find a way of setting the fan speed in this circuit so that it
will always run at maximum speed:

http://homepage.ntlworld.com/davidsallows2004/March-13,-2005.gif

I guess it is a 2 speed fan motor.

Also, will running the fan at maximum speed also run the compressor faster?

 

[Active8]

On Wed, 16 Mar 2005 00:59:47 GMT, jim wrote:

Could someone please help me to find a way of setting the fan speed in this circuit so that it
will always run at maximum speed:

http://homepage.ntlworld.com/davidsallows2004/March-13,-2005.gif

While I wait for it to download, I'll keep myself awake by helping
you with tips for making smaller images. A scan like that would be
smaller if it used the compression found in a jpg (or jpeg) image.

You wouldn't need that at all if you set your scanner resolution to
"black and white drawing" as opposed to photo quality. Then you can
get a smaller GIF, or better yet, PNG image. You might have to play
with the settings to get a legible image.

I guess it is a 2 speed fan motor.

Then guess at some more info to help us out. Like whether this is an
auto circuit or something else. Otherwise, post to rec.puzzles.

Also, will running the fan at maximum speed also run the compressor faster?

Shouldn't. Auto compressors run off the engine speed, no? And the
wiring to it would be for the fan clutch. But I'm seeing a symbol
that hints at an AC motor and compressor and you don't know if the
FSC board is installed or what's in the FSC circuit, I bet. Is this
from some heavy equipment like an earthmover?

I bet if you interchange the RD & BLK pair, the speed will be
different under the same conditions. If that's the case, whichever
one is enegized at hi speed is the one you want to always be
energized. Tell us what this is and why you want to change it.

Don't fry yourself.
--
Best Regards,
Mike

 

[jim]

Hi Active8, sorry about the lack of info:

It's a very old cooling unit that is mounted on a roof. It has a fan, which draws heat away from
a radiator. The compressor converts freon gas into low pressure, which circulates down inside the
building and comes back up at the same pressure of higher if heat has been absorbed.

I want to run the fan and compressor at max speed because it is not cooling enough.

yes, my image is a bit on the large side. That's what happens when you are short-sighted like me.
I will reduce it's size shortly.

 

[Fred Bloggs]

jim wrote:

Hi Active8, sorry about the lack of info:

It's a very old cooling unit that is mounted on a roof. It has a fan, which draws heat away from
a radiator. The compressor converts freon gas into low pressure, which circulates down inside the
building and comes back up at the same pressure of higher if heat has been absorbed.

I want to run the fan and compressor at max speed because it is not cooling enough.

yes, my image is a bit on the large side. That's what happens when you are short-sighted like me.
I will reduce it's size shortly.

Well- refrigeration is also something you know little about- you have
some fundamental misunderstandings with that explanation. You don't want
to modify a thing- if you increase the fan speed then the unit will fail
to develop enough head pressure under cold ambient to keep the expansion
value in its range of operation for proper regulation- reducing the
cooling capacity again. Rather than fiddle with fan speed you would want
to first clean the condenser coil with chemical agent specifically
designed for that purpose- this usually involves using a hose and spray
bottle- goggles and gloves- also the fan blades- any obstructions that
may have developed- and repair any deterioration that may occurred with
the fan cowling material and airflow ducting. Or you could just call a
refrigeration service- and let them size the situation up- before you
are shut down by the inspection authority for failing to meet code in
cooling your product- or worse- make someone ill.

 

[Active8]

On Wed, 16 Mar 2005 15:40:27 GMT, Fred Bloggs wrote:

jim wrote:
Hi Active8, sorry about the lack of info:

It's a very old cooling unit that is mounted on a roof. It has a fan, which draws heat away from
a radiator. The compressor converts freon gas into low pressure, which circulates down inside the
building and comes back up at the same pressure of higher if heat has been absorbed.

I want to run the fan and compressor at max speed because it is not cooling enough.

yes, my image is a bit on the large side. That's what happens when you are short-sighted like me.
I will reduce it's size shortly.

Well- refrigeration is also something you know little about- you have
some fundamental misunderstandings with that explanation. You don't want
to modify a thing- if you increase the fan speed then the unit will fail
to develop enough head pressure under cold ambient to keep the expansion
value in its range of operation for proper regulation- reducing the
cooling capacity again. Rather than fiddle with fan speed you would want
to first clean the condenser coil with chemical agent specifically
designed for that purpose- this usually involves using a hose and spray
bottle- goggles and gloves- also the fan blades- any obstructions that
may have developed- and repair any deterioration that may occurred with
the fan cowling material and airflow ducting. Or you could just call a
refrigeration service- and let them size the situation up- before you
are shut down by the inspection authority for failing to meet code in
cooling your product- or worse- make someone ill.

Yup on the service guy and yup on the cleaning. If I don't clean my
A/C filter, it not only doesn't cool, but the condeser coil freezes
up, making the problem worse.
--
Best Regards,
Mike

 

[jim]

you're right, I don't know much about refrigeration and neither do "howstuffworks.com" because
that's where I got my information about the freon gas circulating around, etc.

That's a good idea about cleaning the coil. I'll try that if I can find the right chemical. I've seen
a few self-rinsing cleaners around on the net.

Don't worry, the cooler is not for food products.

 

[Rich Grise]

On Wed, 16 Mar 2005 15:18:28 +0000, jim wrote:

Hi Active8, sorry about the lack of info:

It's a very old cooling unit that is mounted on a roof. It has a fan, which draws heat away from
a radiator. The compressor converts freon gas into low pressure, which circulates down inside the
building and comes back up at the same pressure of higher if heat has been absorbed.

I want to run the fan and compressor at max speed because it is not cooling enough.

yes, my image is a bit on the large side. That's what happens when you are short-sighted like me.
I will reduce it's size shortly.

Don't screw around with an air conditioner. It's not cooling because it
needs to be serviced by a proper HVAC service tech. Just topping up the
freon could help; but it _will_ have to be cleaned and everything, just
as Fred Bloggs has said.

Sorry.
Rich

 

[Fred Bloggs]

Active8 wrote:

On Wed, 16 Mar 2005 15:40:27 GMT, Fred Bloggs wrote:


jim wrote:

Hi Active8, sorry about the lack of info:

It's a very old cooling unit that is mounted on a roof. It has a fan, which draws heat away from
a radiator. The compressor converts freon gas into low pressure, which circulates down inside the
building and comes back up at the same pressure of higher if heat has been absorbed.

I want to run the fan and compressor at max speed because it is not cooling enough.

yes, my image is a bit on the large side. That's what happens when you are short-sighted like me.
I will reduce it's size shortly.

Well- refrigeration is also something you know little about- you have
some fundamental misunderstandings with that explanation. You don't want
to modify a thing- if you increase the fan speed then the unit will fail
to develop enough head pressure under cold ambient to keep the expansion
value in its range of operation for proper regulation- reducing the
cooling capacity again. Rather than fiddle with fan speed you would want
to first clean the condenser coil with chemical agent specifically
designed for that purpose- this usually involves using a hose and spray
bottle- goggles and gloves- also the fan blades- any obstructions that
may have developed- and repair any deterioration that may occurred with
the fan cowling material and airflow ducting. Or you could just call a
refrigeration service- and let them size the situation up- before you
are shut down by the inspection authority for failing to meet code in
cooling your product- or worse- make someone ill.


Yup on the service guy and yup on the cleaning. If I don't clean my
A/C filter, it not only doesn't cool, but the condeser coil freezes
up, making the problem worse.

The cold coil is the evaporator, the hot one is condenser.