Dispatched to investigate system not keeping up. Upon arrival, client directed me to the thermostats operating inside of the facility. Two of the three thermostats were turned off. After turning on two thermostats, I went to the roof and found only one to be running. The ceilings are 10 foot inside the building. They are split systems. They are not rooftop units. I added 3 pounds of 410 A to the system that would come on. if further investigation is needed or wanted, I will need to bring a taller ladder to find out why 24 V is not being applied to the contactor on the roof for the condenser. 3#