entral ac not working

went to turn my ac on for the first time this year and nothing just a slight buzzing from the outside unit. so I pulled the electrical panel of and contactor is closing have 27 v from signal wires. But when I test power at power wires I have 120v at both wires the ground but when I test between the wires it reads 0v and if I understand right it should be 240v.

any help is greatly appreciated

entral ac not working