Arrived at church for cooling maintenance on four systems. Did thorough evaluation of all systems. Changed the filters of 3 out of 4. The basement system had no filter and we did not have the correct size. All systems had correct delta ts. Flushed all condensation drain lines with gallon of water. All but one system had correct charges and that was the mid level Goodman unit. We added 3 lbs of r410a to the system. Now system has correct pressures. Electrical readings are within limits. Middle level unit has no water safety. Good man unit had no vent free caps and the electrical contactor was a bit burned.