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Detail: This e-log entry by Doug Preddy is being made to clarify the T2 water package temperature read outs. The temperature read outs on the T2 water package have been switched. The read out for inlet temperature is actually the outlet temperature and the read out for outlet temperature is actually the inlet temperature.
On Sunday Oct 19 2014 at 19:45, the T2 water outlet Temp (T2) started to climb giving warning messages at 20:05. Operators tried to decrease the BL1A current, but the temp. continued to climb and eventually tripped the beam off. Operators defined BL1A OFF, and continued to inject to BL2A only. They tried to contact I. Earle, but were unable to. They left message with D. Preddy. The T2 temp. stayed at 45 deg., operators tried to reset the water package and start it, but it tripped almost right away, and increased the temp. by 0.5 deg. Beam was left off.
On Monday Oct. 20 Ron Kuramoto found a replacement thermister. It was wired in to the BOP over the south catwalk. The T2 outlet temperature immediately dropped to ambiant. From this test it was concluded that the installed thermistor on the T2 outlet water pipe had failed. The wiring was restored to the original configuration.
It was decided to switch T2 Water Inlet Temp and Outlet Temp sensors at the T2 electronics rack to provide a trip on the Inlet Water temperature instead of the outlet Water Temperature. As the T2 water package runs in a closed loop, the outlet temperature signal has been swapped with the inlet temperature by Doug P. and Tony T. This will provide thermal protection (trip at 45C) in addition to the T2 Target high limit bit (trip at 60C). The water flow to this circuit is also monitored and will trip if the flow drops.
This action was approved in a meeting with Doug Preddy, Ron Kuramoto, Grant Minor, Yuri Bylinski, Lia Merminga, and Bob Laxdal present on Monday Oct 20th. There is a second, redundant temperature sensor on the outlet of the target water which was installed recently as a safety upgrade to protect the heat exchanger and meet CSA pressure vessel code, see dwg TBP0902. There is a controller for this sensor with a hard-trip switch for the cyclotron, and a temperature read-back display on the Meson Hall mezzanine racks. This read-back should be monitored by operations once per shift while beam is on target to ensure that outlet water temperature is stable and at an expected value.
Sensor cabling swapped at Meson Hall, south mezzanine, bay 1, B.O.P. #3. Sensor T1, cable #12102 moved to TB1, terminals 3 & 4. Sensor T2, cable #12105 moved to TB1, terminals 1 & 2. Defeat #7131 removed.
Defeat# 7133
Fault report #7722
Will look into replacing the faulty Thermister in the 2015 major shutdown.
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