We recently replaced the original liquid nitrogen level sensor with a new one base on capacitance measurement from America Magnetic Inc. The new sensor, solenoid valve and Model 186 level controller are used for the monitoring and Auto-Filling of liquid nitrogen.
The setting used as of 2013
Interval 25 min Maximum fill time
Length 5.5 inch DO NOT CHANGE
LO 20 % Relay contacts are closed à Warning
B 35 % Fill
A 85 % Stop filling
HI 100%
For the liquid nitrogen trip (warning) to work on the Remote Annunciator Panel of Helios with the LO signal from the Model 186, we had to reverse the logic in the Remote Annunciator box.
Relay RT2, move 2 wires labeled 9. From the top left corner to the lower right corner of terminal block #2.