An old customer called me out the other day to look at his York chiller. He has been experiencing nuisance trips on "low oil level" in the tank / separator. I started looking for the tank sensor but after going over the entire tank the only external connection is for the heater, no sensor to be found. I have watched it trip when the oil level is at the half line in the upper glass so I don't believe it is a true fault but a false one. Question is if there is no level sensor in the tank then how does York classify this safety? Do they look at oil pressure? When it did trip the oil was stable as very little foaming and the chiller was about 60% loaded with 82 ent cond water and 45 lvg chilled water. Thanks for the help.