Came out today for a no ac call. Upon arrival I found the York package unit calling for ac but not operating. Model #Zf036n08a2aaa2, serial #N1c4533555. I set up my 28 foot ladder that barely made it and went on the roof. I opened the access panel and noticed a loose connection on the contactor. I powered the system down and tightened the connection. I powered the system back up and it fired right up. I observed the system running for 20 minutes. The temperature split is at a 20° differential. The system is operating properly at this time. Highly recommend performing maintenance on both rooftop units. Both York package units , 3 phase, natural gas, no belt on blower motor. Both systems have 2 filter racks inside sized 15x30x2. Spoke with customer regarding a commercial agreement. He is interested and would like a price submitted to him. I documented all information necessary to provide the quote to customer for both systems. Please call the office at 215-672-8112 to provide price &