Blower motor speed adjustable?

[Max78]

Just put a used all-in-one Rheem AC unit on my parents house. The unit is sized correctly according to a friend who is a HVAC tech. 3 ton for 1500sqft in AZ.

Its all up an running and blows cold, the only thing is it doesn't seem to blow very hard through the vents. Living in a dry climate we don't really need humidity removal so i was thinking of bumping up the blower motor speed if that is possible on this unit. I'm not sure if it is though and just looking for some guidance.

The blower motor has 4 wire coming out of it, Red, Black, Orange, and Brown.

My HVAC tech friend takes weeks to respond sometimes so that's why I'm asking here.

This is on a Manufactured house and we used the best insulated 12" flexible ducting we could get (R9). There are no kinks and it is supported with a wood carriage to keep it off the ground and prevent kinks. It is as short of a run as we could make it.

Any insight would be greatly appreciated!

Edit: This unit does not have a control board, it uses the 24v transformer.

 

[Bolson32]

Where do those wires go? Black is usually high speed and is generally reserved for AC, even in Northern climates.

But you'd need to check the book. Most have a diagram in them.

Sent from my SM-N981U using Tapatalk

 

[Max78]

The whole unit has been painted, the information card is sun faded and now has no text and the wiring diagram has long been gone. . . haha, ill see if I can get pics on the wiring today.

I have literal no info other than its a Rheem, makes it very hard to deal with.

 

[Max78]

This is the blower relay. Red is plugged in, black was taped off.

Black has lower resistance than the red so I’m thinking that is high speed.

 

[Showkey]

Usually blower speed is adjusted (changed) to get the correct temperature drop over the “A” coil.
Usually 18* drop is the target with plain Jane AC no variable compressor etc.
If it was removed from a working situation.......guess it was set right ?
Most are 3 speed some might be 4 speed.

 

[Max78]

I will just agree with that. haha. The black wire went to the furnace and onto a small fan there. I just like to see what the options are an don't trust anyone to set much up right. . .

I just helped my mom fix her fan in the bedroom that was there from the PO. Not only was the bracket upside down, the blue light wire was connected to ground....

I'm just going to leave it and have my HVAC friend come verify everything is in good working order and setup correctly. I know enough to get it running and plumbed in but not much else other than that.

 

[Terry D]

Black is usually high. Red is low. As far as the other two, Orange could be medium. Brown usually goes to the cap. If you are sure all 4 are speed wires. Then do a resistance reading. Go across common and each speed wire. The highest resistance will be your lowest speed. So check each wire, as the resistance decreases, the speed increases.

You need proper CFM across you A-coil to get maximum efficiency and humidity removal. Its around 400 cfm per ton. But you are going to need some meters to calculate cfm. Either static pressure, which you are going to have to know the engineering date of the unit or a anemometer. You can also measure the delta T, which is the temperature difference of the air entering and leaving the A-coil. If this is a older unit, should be around 18-22 degrees. If it is higher than that, you possibly may need to increase the blower speed. And that is based on all the ductwork being sized correctly.

There are a lot of good videos on you tube on this. AC Service Tech is a good channel.