2020 Tech Report May-June

Task # 2.b.: Performing Float Switch Testing on Liquid Make-Up Systems With- out a Drain Valve

ACTION

COMMENT

6.

Observe the following positions of the float switch magnets in relation to the at- tractor rod inside the hermetically sealed switches: · As the level of ammonia in the float column rises, the magnet should press against the attractor rod to make the float switch’s High Level Alarm (HLA) initiate an alarm. · As the level of ammonia in the level column rises, the magnet should press against the attractor rod to make the float switch’s High Level Shut Down (HLSD) trip, sending a Shut Down signal to all associat- ed compressors within the engine room. · If there is a level probe present, verify the calibration of the level probe. When the liquid level is above the float switch position and the float switch has been determined to be working or in need of replacement, continue to the next step. Change the liquid make-up solenoid or the electronic expansion valve back to the automatic position.

The High Level Alarm must activate an audible alarm inside the engine room.

All compressors attached directly to the suc- tion of the tested vessel must shutdown or alarm. If they do not, consult your supervi- sor or facility contact to determine the proper course of action.

If the test determines faulty equipment, con- sider performing level probe calibration at this time.

7.

RETA TECHNICAL REPORT PAGE 15