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Solenoid logbook

Fields marked with * are required Entry time: Wed Jan 15 13:45:32 2025 Author*: - please select - Doug Preddy Curtis Ballard Kevin Trithardt David Kishi Experimentor Other Operational Mode: - please select - Normal Running Quench Recovery Start Up Shut Down Maintenance Other Subject*: > Got a call at about 10:00 this morning, the whole system had tripped off. > No power bumps or other disturbances. When I arrived the only fault > indications were "ColdBox Trip" light on the compressor panel and on the > QRL panel the red "ColdBox" LED was ON. On the SULZER panel the > yellow "Cryostat Quench" light was ON. On the First Trip logger #1 and #15 > LED's were ON. But no indication about what the actual fault was. Cooling > water OK, compressed air OK, compressor ventilation OK. Outside ambient > temperature was cooler than we had last week. BIG1 was off but when I > turned it back on the vacuum looked good but was slowly rising as the > solenoid warmed. I put the jumper on the vacuum controller. Prepared system > for re-start. > > Started compressor. Started flow thru coldbox. Raised discharge pressure. > Started turbine flow. Didn't get any freezing but it seemed that T1 speed > wandered slowly +/-0.1k rev/sec when it got up to about 3.6k revs/sec, but > this only lasted for a second or two. Not sure if I was just seeing things. > Got turbines up to speed and started // warm return flow. Solenoid had been > running at 500 Amps and when it quenched and sat warming it had warmed to > about 40 K. Switched it to //cold return too soon and solenoid started to > warm slightly. Back to // warm return mode. Had to throttle flow thru > solenoid with warm return valves to get effective cooling. If had return > valves wide open TI121 would warm up too much. Discovered that if I > throttle the flow out of the solenoid slightly then TI121 would fall and > solenoid would start to cool. Less flow gave more cooling. Don't quite > understand that one. Switched to // cold return mode when solenoid temps > falling below 20K. > > About 15:00 stable // cold return cooling. Going home for a while. > > 19:30 solenoid temps bottomed out at about 11K. Switch to series mode. > Something strange about the first trip detect. I reset it once and when I > checked it an hour or two later it showed a trip on #1 and #15 LED's even > though nothing had happened. Something must be causing false indications. > > 20:15 series cooling, solenoid temps at about 6K, LHe level rising slowly > at about 10%. Removed jumper on vacuum controller. Encoding: HTML   ELCode   plain   Suppress Email notification Attachment 1:

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