On Jan 18, 7:16*pm, " wrote:
Our office has a rooftop Lennox THA090 AC unit. It comes with 2
compressors. Almost everyday we have to go to the roof to restart the
compressors because they often will trigger an internal circuit
breaker that protects the compressors. According to the PCB board that
is next to the compressors, when it trips the breaker, it says it is
because of a High Pressure fault (LED1 will flash, and LED2 will be ON
solid). *What would cause this fault on a daily basis?
Thanks for any tips!

Here are some pictures of the AC unit:http://www.flickr.com/photos/5423000...07/8392973520/

1) use a clamp on Ammeter to verify that the current is indeed high

2) use a pressure gauge to check the high side pressure to see if is
indeed high

3) check that the condenser coils air flow is not blocked or dirty and
that the condenser fans are running correctly

Mark