Hey guys, I have a head scratcher for you.

Overview: I have an arena with a single Mycom 8WB compressor pulling its suction from a flooded shell and tube chiller. The chiller liquid level controller is a Hansen Vari-level with a 20" probe fitted to a 4" column that controls the liquid line solenoid. There is also a mechanical high level cutout.

Problem: When the system is running the liquid level in the chiller is maintaining at the bottom of the top sight glass with the Hansen controller reading 70% and once the system satisfies and the the plant shuts down the liquid level will increase and trip the mechanical high level with a reading of 110% on the controller. The increase from 70% to 110% takes 10 seconds. Where is all this liquid coming from?

Theory: Suspended liquid in the surge drum is released at shutdown. The higher liquid level you maintain in the chiller the more suspended liquid there will be in the surge drum. Even after lowering the liquid level the same problem occurred. The liquid line solenoid is not leaking and has been ruled out as a problem.

Any thoughts?

Thanks in advance!