Kevin and I were at the Sulzer panel when the system quenched 2. No 
obvious reasons. Restarted the system.

From about 08:00 to 15:00

See Doug's previous entry for quench recovery details.
First the system had been set to // cold return mode because the solenoid 
temps seemed low enough. Temps started to rise instead of cooling so system 
was eventually set back to // warm return mode. With the system in // warm 
return mode the solenoid was still warming instead of cooling. Solenoid 
temps were rising to almost 50K and T1 shield heater was about 90%. T1 
inlet temp was below 75K and falling even with shield heat set so high. 
CV155 kept closed and // warm return flows were full flow. T1 brake valve 
seemed way too open at about 0.8 (compared to previous runs).

15:00 to 19:00

Tried opening CV155, didn't seem to help much. Temps still trending 
upwards. Decided to reduce flow to solenoid to see if the cold box would 
cool down. Started reducing the // warm return outlet valves. TI121 began 
to drop slowly. On graph plotting solenoid temps they started to trend 
downwards. Weird. A reduced flow seemed to produce more cooling ? Don't 
understand this but will continue. Flow temps returning from solenoid were 
about the same temp as TI121, about 35 K. Switching to // cold return mode 
to try to reduce TI121. Keeping CV155 as open as possible, just keeping 
CV204 from closing completely. After switching to // cold return TI121 
starts to slowly fall, T1 inlet temp rises over time so start to drop 
shield heater setting. Solenoid temps now trending downwards. Cracked open 
CV142 to get some flow going through powerleads. Raised compressor 
discharge press to about 11.2 barA. Shield heater down over time to about 
10%. Reduced CV155 down to the point where temps almost stop falling then 
open cv155 just enogh to keep temps falling.

19:30 Solenoid temps down to about 28K. Letting system continue cooling 
overnight.

Guessing the cause of the turbine overspeed quench was caused by 
contamination entering the spinning turbine, causing rapid speed changes or 
possibly the continued saga of the water damaged Jaquet turbine speed 
tachometer giving random false trips.

Got pager call at 16:20 this afternoon. Solenoid had tripped on PL 
temperature. Arrived at about 17:00. Did a print screen of the striptool 
graph and solenoid screen. See files Prtscrn1_april25_2004.doc and
Prtscrn2_april25_2004.doc. System was in idle running mode. LHE heater at 
about 30%, buffer tank press at21.5 psig, shield heater at 37.5%. The
jumper is still on the back of the vacuum guage PIC901. The compressor 
building backup air compressor was tripped again, I reset it. HIC 141 was 
set to 0.46 , I set it to 1.1 (closed position). Set solenoid inlet and 
outlet HIC's to valve closed positions. Energized warm return HIC's then 
slowly opened warm return valves to vent pressure in solenoid. Cracked open 
solenoid inlet valves to get abot 1.5 barA pressure on PI143 and PI146. LHe 
level started to drop. Contiued slowly until all LHe boiled away. PI143 and 
PI146 at about 5 barA. Had to adjust turbine speeds and shield heat. Opened 
cold returns then closed warm returns. Gradually increased solenoid inlet 
valves until wide open. Adjust turbine speeds and shiled heater. At about 
21:00 stable // cold return cooling. Temperatures dropping gradually. See 
files april25_2004_2113.BMP and april25_2004_2114.BMP 

Have powerlead supply valve HIC142 open to 0.46 during cooling just to see 
what happens. Time now about 21:42. Leaving system in // cold return 
cooling. Should be ready for series switch over in the morning.

Solenoid quenched at 6:45.  All temperature monitors were flat until trip.  
Hearing compressor stop was first warning.  Lights are:
Turbine T1 overspeed,  Compresor alarm, cryostat quench.

--Donald Arseneau

power lead temps caused a quench at 8:30 this morning. Recovery of system 
and flow to solenoid was started by 11:00. Solenoid was switched to series 
cold at 3:00. Solenoid and power leads were cold at ~6:30. power supply 
was to be energized by experimenters.

I had distributed this list by email earlier this month. I have added
a few items at the bottom. I am posting it on the M9SOL Elog under
Maintenance. Some of the items may not be achievable or practical but
I thought it would be a useful first attempt at a To-Do list.

> I had distributed this list by email earlier this month. I have added
> a few items at the bottom. I am posting it on the M9SOL Elog under
> Maintenance. Some of the items may not be achievable or practical but
> I thought it would be a useful first attempt at a To-Do list.

A couple of other things to add:
Rebuild cooling water circulation pump with new seals and bearings.
Add air bleeds to the copper nonactive water lines.
Doug

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.

Don't Panic -- There was no quench. I am testing the e-log.
I have added Kevin's name and e-mail to the M9 e-log. He will be e-mailed 
when a quench recovery log is submitted. His name is also included in the 
Author's list. 
Thanks, Doug

I will leave the cold box to warm overnight and try it again in the morning.

Started flow to turbines. Both started. T1 seems a bit slow. HIC110 at 0.85 
SI110 = 4100.
Cool down started.

T1 will not spin up. Warming up cold box.

Buffer tank pressure is down to about 6 psig. Too low to keep up
with liquefaction requirements to build LHe level. Doug Preddy
requested that I help Curtis Ballard top up system with new
bottle of UHP helium Through purifier. As of 09:45 not yet able 
to find Curtis.

PI229 discharge pressure dropped slightly to 10.45 barA. Set point
is 11 barA. Turbine speeds OK. CV211 is wide open. Energized HIC142
and set to 0.7 to start flow to powerleads. Up in compressor room
checked purifier. LN2 system running OK. In purifier package flowmeter
looks like oil or brownish spots on inside of rotameter glass. Possible
migration of trapped contaminants after correcting flow arrangement
through purifier. Initially buffer tank circulation flow entered
through AV3 but was corrected to enter through AV5.

Have 10:00 meeting, system seems stable and should be OK until I can
contact Curtis to top up system with UHP helium through purifier.

No experiment running in M9B.

Solenoid current is zero and power supply not armed.

System in stable series cooling mode.

M9BMP2 was replaced. Vacuum good. Solenoid is ramped up. :)

Cool down continues.