I've got two 750 ton York OTS4G chiller units (old school, vintage '75). Our operators have been checking the oil level in the standby unit (the one not in operation) by running the oil pump for 5 minutes and then recording the oil level. They do this once per day, every day on their rounds. Keep in mind that we swap chillers every two weeks, so the one in standby has this done once a day every day for 14 days before it is placed in service. One tech rep told me that wasn't a good indicator of oil level because running the oil pump without the chiller in operation moves the oil around in the chiller without the oil return system functioning to bring it back to the reservoir, and that some oil could migrate to the condenser. I'm looking for some additional technical justification to remove this activity from their rounds. Any thoughts?