[Hallb-solenoid] [New Logentry] Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Solenoid Cooldown

[Scot Spiegel]

R. 

Has anyone done this? 

Scot Spiegel 
Physics / Hall D 
JSA Jefferson Lab 
12000 Jefferson Ave. 
Bldg. 55 Rm. 1546-24 
Newport News, VA. 23606 
Ph. 757-536-5900 
Wk. 757-269-5900 


From: "Ruben Fair" <rfair at jlab.org> 
To: "Pablo Campero" <campero at jlab.org>, "Brian Eng" <beng at jlab.org>, "Nicholas Sandoval" <sandoval at jlab.org>, "Scot Spiegel" <spiegel at jlab.org> 
Sent: Sunday, August 20, 2017 6:19:16 AM 
Subject: Fwd: [New Logentry] Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Solenoid Cooldown 


Pablo, Brian 

See note below 

Can we swap to the backup temp sensor for TR8672? On Monday 

Thanks 

Ruben 

Begin forwarded message: 




From: kashy at jlab.org 
Date: August 20, 2017 at 6:00:02 AM EDT 
To: rfair at jlab.org , ghoshal at jlab.org , renuka at jlab.org , gyoung at jlab.org , burkert at jlab.org , josephm at jlab.org , rossi at jlab.org , ent at jlab.org , hogan at jlab.org , dinsley at jlab.org , mont at jlab.org , lung at jlab.org , stuart at jlab.org , kashy at jlab.org 
Subject: [New Logentry] Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Solenoid Cooldown 




BQ_BEGIN

Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Solenoid Cooldown 


Lognumber 3482084 . Submitted by kashy on Sun, 08/20/2017 - 05:58. Logbooks: 	HBSOLENOID CLOG 
Entry Makers: 	kashy 
References: 	3482067 - Follow-up Re: Follow-up Re: Follow-up Re: Follow-up Re: Solenoid Cooldown 


The shield cooling rate dropped appeared to drop from 0.4K/hr to 0.2K/hr at ~22:20 on 8/19. Temperature sensor TR8672 stopped changing at that time. It may be a bad sensor or something else. Other temperature of the shield appear to be dropping at the original rate, so I expect that it is just a sensor problem. This sensor is located in the SST and we should be able to switch to its backup on Monday. There is no control issue. 

We are using coil resistance to calculate the bulk temperature of each coil, coil 5 dropped below the water freezing point early this morning. Now its 272K. 

I turned on alarms on the load cells 

Radial bottom will alarm at 10,000lbs except the beam right bottom is set for 11,000 
Radial top will alarm if below 300 or above 1000lbs 
Axial (Z) supports will alarm if above 300lbs. 
All of these are well below critical limits but will give us a heads up if things start to change. 

To assist in cooling the shield a bit faster I have changed the PID setpoint of EV8670BY from 0.12atm to 0.32atm. Thus far the indicated cooling rate of the shield has increased to 0.3K/hr. This will reduce again to 0.2K/hr after the shield has cooled. Once the spare TD8672 has been put on line the displayed rate should go back to ~0.4K/hr. 

BQ_END

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