Air Conditioning - Carrier Infinity 21 Condenser Hum

I just had an Infinity 21 SEER 5-ton system installed over two weeks ago and from the start, the condenser unit outside had an annoying hum/whine. I called the technician out where he looked at the unit and said everything was ok. He brought to my attention that it was normal as it was the fan motor making this noise. He unplugged the fan while the unit was running and sure enough the sound went away. But it is very annoying when the system is running as my home office is near where the condenser is located. per the Carrier brochures, this system operates at 70db - as quiet as a refrigerator...this is not true! Any advise?

The lineset penetrating the wall - It may be transmitting the sound - Insulate it from touching the house as it enteres the wall.