PDA

View Full Version : Fan motor rpm control



thom
15-05-2008, 12:01 PM
Hei...i'm new to this forum.:off topic:

I'm confuse in limitation of fan motor rotation control...
(pressure or temperature based) Someone have a good reference to read??

chemi-cool
15-05-2008, 09:28 PM
Outside (condnser fan) - controlled by head pressure.

Inside fan ( evaporator) - controlled by temperature.


Chemi :)

herdian
16-05-2008, 03:28 AM
What minimum rpm do the fan can achieve?
Say, the condenser head pressure drops due to low ambient temp. (lowest amb. here never below 15C, I think :() but there in area who experience winter? because of that the condenser fan needs to lower it's rpm based on setting, do the correlations make the rpm possible to achieve 0 (off)? do the range is always between 0 to max rpm?

brianubaldo
16-05-2008, 03:37 AM
What minimum rpm do the fan can achieve?
Say, the condenser head pressure drops due to low ambient temp. (lowest amb. here never below 15C, I think :() but there in area who experience winter? because of that the condenser fan needs to lower it's rpm based on setting, do the correlations make the rpm possible to achieve 0 (off)? do the range is always between 0 to max rpm?

condenser fan is controlled by head pressures. check the manitowoc brand for specific speed of fan.. head pressure chart list!..

in evaporator,. it can also be controlled by the micom. in micom you can change speed depends on option code you had input!. depends on the design of the unit!

jvdwaalv
08-06-2008, 02:20 PM
The minimum fan speed is approx 25%. Any lower might cause overheating due to the current distortion caused by the VSD and lack of the cooling of the internal fan. technical is it not required to go any lower since the performance of the fan below 25% is very low. Just condensor fan controll based on condensor pressure alone is not the most economical way. Especial at low load and cool enviroments gives the reduction of condensor pressure a big reduction in energy consumption.

icecube51
08-06-2008, 02:33 PM
why change the rpm's ???
or is the original fan brocken???:)

Ice

Brian_UK
08-06-2008, 11:16 PM
why change the rpm's ???
or is the original fan brocken???:)

Ice
Please check the original post.

thom
09-06-2008, 06:49 AM
Ok brianubaldo, jvdwaalv thanks.

@icecube51, no i don't even have any fan to be broken.

Since Brian_UK doesn't give any responese to jvdwaalv hint, I'll take jdwaalv hint, thanks

icecube51
09-06-2008, 09:24 PM
yo brian,

its common fact,they ask about a piece of how its normally works,then the tell you " ok,its brocken ".

so i wanted to go straight to the point,

grtz, ice