I have a Lennox Model HS14-651U-3P that shuts down aprox. 30 seconds after starting. I hear a relay click and the unit shuts down. Any help would be greatly appreciated

I am having the same problem. Have you figured anything out yet?

The compressor may be low on Freon, or the theromstat may be defective. If the compressor trips an overload device the compressor may be defective.

Umless you are knowledable how to trouble shoot electrical and refrigeration equipment, you need to call in a tech.