Had a service call the other day, customer was complaining they had 2 units that had been tripping on high head periodically over the past few months.
I checked the head pressures on the units. 225psi and 330 psi for R-22 and 410a respectively. Entering water temperature was 42°F, water reg. valve was in good shape.
I see that the 3-ton unit calls for a 3/4" water connection but had been bushed down to 1/2". The 6-ton had the proper sized 1" line.
Here is a photo of the piping arrangement...
Not sure what the supply water pressure is, there was no gauge in the line. Should they be able to achieve the proper flow with this line size? If so, what pressure is required?
Seems to me like the water main should be larger. The 3 ton unit was a new addition about a year ago.
The gpm's were taken from the manufacturer's literature for the given water temperatures. 45°F and 65°F for winter and summer.
Worst case scenario they would require 10.5 GPM in the summer if both units were running full out.