Today Grant Minor, Dan Wright, Arthur Leung, and Dan Louie checked the height difference between the tank lid upper travel limit switch and the tank lid over travel limit switch at both stations 1 and 10.

In the attached photos, the upper travel limit is the lever on the right.  The over travel limit is the lever on the left.

The over travel limit is a safety switch designed to halt the system and lock it out if there is some problem with the upper travel limit.

The following tasks were performed:

1. The new reference positions for the brackets after the March 11th adjustment of 0.25" (see previous e-log) were scribed onto the mounting posts for Stations 1 and 10
2. The brackets at both Station 1 and Station 10 were unbolted and raised up completely to disengage the switches.  This had to be done due to mechanical hysteresis in the switches.  Dan Louie confirmed when the upper limit / over travel limit signal lamps had turned off at the control rack.
3. The Station 1 bracket was bolted up higher temporarily so that both switches were disengaged at that Station.
4. The Station 10 bracket was positioned back at the new scribed reference line from step 1.
5. A 1/8" nominal machinists parallel was slid under the lever arm of the over-travel limit switch at Station 10, and Dan Louie confirmed that the over travel lamp had turned on.
6. The Station 10 bracket was unbolted and raised to disengage both switches, and bolted in this higher position.
7. The Station 1 bracket was then positioned back at the reference line from step 1.
8. Step 5 was repeated for Station 1, confirming that the over travel lamp engaged after the 1/8" parallel was inserted under the switch.
9. Both brackets were positioned back at the reference positions from step 1 and bolted in place.

This procedure confirmed that the over travel limit switches at both stations 1 and 10 engage less than 1/8" higher than the upper limit switches.