Carrier- Outdoor Fan unit is not spinning fast enough...help!

Outdoor Fan unit is not spinning fast enough, what could be the problem? Replaced motor and capacitor. What else could be the problem?"

if its a 4 pole motor 1 of the poles could have failed

Is there a fan speed controller in the circuit?

measure the voltage from PCB

I have had this problem with a Carrier/Apac system and found that there was a fan speed modulator or controller which is wire to the main pcb. repleced that item and solved it although it was hard to get the part as no one had it listed, quit a hassle.

Check inverter .

If it's a suitable voltage motor (and has the capacitor wired locally) you could disconnect it from any control board and test it on full supply voltage. If it runs fine the problem may be the PCB or possibly a pressure /temperature transducer.

Back to basics guys......

OP - what is your 'not spinning fast enough' statement based on?.... high head pressures? ... experience?....not cooling enough?...etc etc. More information please.