NIRC-2 CCR Off Procedure

Note: This write up from Randy Campbell was in preparation for vibration testing on 26 April 2002.

1. Take series of darks for "before" sample of noise.
2. Adjust Loop B Alarm to 80 K on lakeshore 340.
	completed 25 Apr 2002 with command:
		td 5 "alarm b ,1,1,80.0,0.100,1,1  
	check the current setting with: 
		ad 5 "alarm? b"
3. Turn cold heads off via computer control. These are apparently keyword
controlled according to the list of remote commands:
http://www.keck.hawaii.edu/realpublic/inst/nirc2/io_commands.html

	sm ch1pwr 		this shows the head 1 power, 1 is on
	sm ch2pwr		show for 2 stage head
	mm ch1pwr = 0	turns off the single stage cold head power 
	mm ch2pwr = 0	turns off the 2 stage cold head power
	sm ch1pwr		confirm they are off
	sm ch2pwr		
(Al Honey, can you please confirm these are the correct commands?)

4. Turn CCR compressor off via main breaker on front left
5. Turn UCLA electronics off
6. Install PLC for UCLA electronics
7. Monitor NIRC2 temperatures during 2 hour CCR power outage 
8. Turn CCRs on with main breaker on front left of unit.
(probably want to take vibration measurement at this point with CCRs on but
not the cold heads. This could help isolate the cold head / CCR
contributions)
9. Turn cold heads back on.
	mm ch1pwr = 1	turns on the single stage cold head power 
	mm ch2pwr = 1	turns on the 2 stage cold head power
	sm ch1pwr		confirm they are on
	sm ch2pwr		

10. Verify temperatures begin to go back down (showtemps command).
11. Turn UCLA electronics on.
12. Monitor  temperatures until NIRC2 reaches nominal operating point.
13. After NIRC2 has cooled back down (a couple of hours should do it) Set
Loop B Alarm back to nominal value (55.0 K)
		td 5 "alarm b ,1,1,55.0,0.100,1,1  
	check the current setting with: 
		ad 5 "alarm? b"
14. Take dark / noise measurements with new PLC installed.

NIRC2 Master
21 August 2002