WP12035

Yesterday thermocouple B (TC-B) failed during the fill. Its wire broke and its temperature railed at +1372C. The fill proceded with TC-A to completion.

If TC-A had similarly failed, the fill would have continued until either the discharge line pressure exceeded its trip pressure; or the fill timed out after 30 minutes.

Today's code modification adds a check when reading the TCs that they are not greater than the nominal_max temps (+40C).

Providing at least one TC is in operational range the fill will continue, but now if no TCs are operational the fill will abort with an error.

The new code was installed at 9am today, it will run for the first time during Thursday's fill.

During this investigation I noted that the discharge_line_pressure trip is 2.0PSI. Operationally this pressure has never exceeded 0.6PSI so I lowered the trip down to 1.0PSI.