First, I want to thank you all for the information I've picked up here!
I know that an undercharge will cause a coil with otherwise sufficient airflow to freeze up. Is the converse true - will an overcharge (no superheat) prevent a coil with insufficient airflow from freezing up? (I'm not sure but I think there's no TXV - 1988 Ruud coil). I assume that's bad for the compressor, inefficient, anything else?
depends on how low airflow gets, but in some instances you might have liquid coming back lower than 32 degrees which in itself could freeze one up.
Airflow is about 275cfm/ton. Is it safe to read your answer as "probably, unless airflow was _really_ low"?
You can over charge a system enough that it won't freeze, it will kill the compressor, but it won't freeze the evap coil.
Why is youor air flow so low?
What is the outdoor unit.
Does it even cool.
Why is your air flow so low?
The contractor installed the wrong furnace (Bryant 355MAV042 instead of an '060) under the existing Ruud UPFA-048. It froze up right from the start, and he came out and added refrigerant. Later, I discovered what he already knew, that it was the wrong furnace. He has said he'd install the correct '060 when business slows down, but that the 042 will be fine, and won't freeze over. Is the reason that he's so sure that it won't because he deliberately overcharged it?
I found out that it was the wrong blower because the condensate is running down into the furnace instead of draining - assuming that contractor knocked something loose on pan so that it leaks. And nobody wants to replace the coil on an undersized blower. ...
It could be.
It could be that a leak started during the install.
Too many possiblities.
The 042 can deliver 1400cfm, which would be 350 cfm per ton, which is ok, and won't harm your condenser.
Unless your in an extreme low humidity area.
Have you called him about the condensate leak.
"Install the correct one when bussiness slows down", and this explanation is coming from the contractor that installed the wrong furnace to begin with, if so, Call the Contractors Board in your state, that is down right unacceptable, especially if they were allready paid to complete a job, and that job was done improperly and you are having problems.
With the unit always freezing and causing exsessive amounts of water to be drained and leakage is evident, things could be damaged in the long run.
split system: evap in attic or garage