 Thu Jul 5 11:01:47 2007, Kevin Trithardt, Other, Current lead warm up
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Due to curent lead temperature occilation Doug recommended warming up the
current leads.
The leads were warmed up this morning then cooled back down. Power supply
is ramping up now.. 2 1/2 hours start to finish. |
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Wed Nov 28 15:07:08 2007, Kevin Trithardt, Other, power lead regeneration
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Power leads cold again, power supply ramping up. |
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Sun Jul 13 20:17:24 2008, Doug Preddy, Other, Helium refrigerator problems
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| In early June the helium compressor was running with the solenoid cold. A vavlve broke off at the suction side of the compressor. The entire helium inventory was lost. The cold box tripped off, but the compressor did not. It ran for ~ 2 hours before I came in and shut the system down. The valve was repairedby Kevin T and Neil Wong. We ran hot (>100C) nitrogen through the fourth adsorber for one week. The solenoid and cold box were allowed to warm above 273C. The compressor, all piping, cold box, solenoid and buffer tank were pumped and purged with helium three times. Liquid helium was boiled off to pressurize the system to 10 psi and bottled gas was added to allow the compressor to start. We started the compressor and ran the gas through the purifier for three weeks. During the third week we added a second purifier. The purity was not measurable with the meter that we had. An RGA was set up to give some information on the rate of scrubbing. After three weeks the gas purity was better that 2 PPM. The system was cooled down. We added ~ 75 LL of heium via boil off to the system.
As the cooling progressed it was noted that the power supply for the 80K shield heater was burnt. An auto transformer was wired into the system and will be used until a replacement power supply can be purchased. |
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Thu Nov 11 15:46:40 2010, Doug Preddy, Other, switched to parallel cold return
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At 14:45. |
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Thu Apr 22 10:39:16 2004, Doug Preddy, Normal Running, Yesterday
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Added two bottles of UHP helium to buffer tank.
Had no liquifation rate, so optimized Ti121 and HIC141 . Finally put TIC121
into manual mode at 0.65. Power lead fluctuation died out and liquid
started building.
This morning changed TIC121 back to auto mode and played with it's setting
to minimize the power lead and TI121 ripples.
TI121 ripples seem tied to power lead ripples.
System seems stable enough to energize the solenoid. |
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Fri Apr 23 09:19:30 2004, Doug Preddy, Normal Running, CV211
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PIC 229 was down to 10.8 bar this morning. PIC 229 was trying to open CV211
to charge the system. I realized that in restoring the control to CV211 I
did not get the wire into the connector properly. Went back up to the
compressor building and reconnected the control wire to CV211. pressure is
back to 11 bar. TI121, LHE in and liquid level ripples are now all reduced.
System was ramped up to 500 amps yesterday at 14:00 |
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Tue Apr 27 09:03:18 2004, Doug Preddy, Normal Running, Power leads
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Power leads are being monitored with the strip tool graphs. I saw the temps
go from having a ripple to almost no ripple, but starting to increase in
temperature. I also noticed that the flow had dropped to 200 mm. I power
cycled hic142. This resulted in an immediate drop in temperature, an
increase of flow to 250 mm, and a slight drop in the LHe level. The temps
seem to be stable, with only a slight ripple. |
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Wed Apr 28 09:30:09 2004, Doug Preddy, Normal Running, power leads again
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Same story as yesterday. Ripples dieing out, flows down to <200 mm, temps
increasing. Turned HIC 142 down to 0.4 then back up to 0.75. Temps dropped
quickly. Then turned HIC 142 to 0 and back to 0.75. Temps dropping, flow >
250mm. Did not let negtive lead >10K, so would not have caused a trip.
TIC 121 into auto mode. |
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Tue May 4 11:20:57 2004, Doug Preddy, Normal Running, power leads going unstable
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power lead ripples increased over last couple of days. They are quickly
dieing out now and the temps are startint to increase. PL flow is down to
<180mm. I will power cycle HIC 142. |
Tue May 4 11:26:38 2004, Doug Preddy, Normal Running, power leads 
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Power cycled HIC 142 with solenoid power at 400 amps. Flows > 240mm and
temps have dropped. |
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Wed May 5 12:13:51 2004, Doug Preddy, Normal Running, power leads cold
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should be ready to run. |
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Tue Jun 29 14:59:46 2004, Willy Andersson, Normal Running, Removed jumper on vacuum controller.
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Tuesday 14:55
Removed jumper on back of PIC 901. This jumper should be off during
normal operation so the solenoid/refrigerator is protected from bad vacuum. |
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Tue Aug 24 12:09:50 2004, Doug Preddy, Normal Running, The past few days
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The solenoid has been re-started as of August 19. It was cooled down and
energized over the weekend. Sunday night at 9:30 it tripped due to
negative power lead going above it's set point. The system stopped flow to
the solenoid, but kept the compressor and cold box running. While starting
flow to the solenoid, we got a high pressure trip. I came in and restarted
the compressor, after Curtis located and reset the over pressure
interlock. The solenoid is cold and energized as of 3:30 pm yesterday. It
is still stable as of now. |
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Wed Aug 25 07:47:05 2004, Doug Preddy, Normal Running, Power lead flow
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The power lead flows had dropped to 210 mm this morning. I increased HIC142
from 0.8 to 0.83. The flows are back to <250 mm and the temps are back to
LHe in-10.8, PL-Pos-11.1, PL-Neg-8.9 |
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Wed Aug 25 12:52:53 2004, Doug Preddy, Normal Running, power lead ripple
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Lhe ripple has started. 10.9-11.4K PL-Pos also has a smaller ripple. Both
flows down to 230mm. Cycled HIC 142 and the ripple disappeared.
Put TIC121 into auto mode. |
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Sun Aug 29 14:39:19 2004, Doug Preddy, Normal Running, Power lead ripple
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The LHe in and PL-neg temps have been building up a ripple over the last
few days. Curtis cycled HIC142 Friday evening at about 5:00. I just had
the Main control room operator (Peter) cycle them again. The ripples died
right out.
Originally the ripple was 10.8-11.4K on the LHe-in and 8.9-9.2K on the PL-
Neg. They are now steady at 10.7K and 8.9K. |
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Mon Oct 25 15:44:15 2004, Doug Preddy, Normal Running, Power lead temps starting to ripple
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Power lead temps starting to ripple at a 1.5min period. PL flows are
both>250 mm. |
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Tue Oct 26 09:45:24 2004, Doug Preddy, Normal Running, power leads warming
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Flow to power leads dropped to <80 mm. Cycled HIC142. Temps dropping, flows
>250. |
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Fri Oct 29 14:25:23 2004, Doug Preddy, Normal Running, power lead flows dropping
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Flow is down to <190 mm. temps are starting to climb. Cycled HIC142 |
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Mon Nov 1 07:17:44 2004, Doug Preddy, Normal Running, power lead flow gone bad
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power temps as follows:
LHE_IN 23
PL_POS 36
PL_NEG 31
Flow <90mm
cycled HIC 142 off and on in 1/2 hour. |