Not an HVAC guru, but I've purchased one in the past
I think if the condensor is freezing it's often due to the condesor fan not working properly or low refrigerant (possible leak). My brand new condensor came from the factory w/ a leak, but the install tech found it right away and repaired it. One last issue may be that the condesor is too small and is being overworked, causing it to freeze. HTH