[Dsg-hallb_magnets] Fwd: Interlocks

[Pablo Campero]

Hello Amrit, 

This is for your information. 

Best Regards 
Pablo 

From: "Ruben Fair" <rfair at jlab.org> 
To: "Pablo Campero Rojas" <campero at jlab.org> 
Cc: "Renuka Rajput-Ghoshal" <renuka at jlab.org> 
Sent: Monday, May 8, 2017 10:25:13 AM 
Subject: Fwd: Interlocks 

Pablo., 

Please refer to John Hogan's email below with regards to load cell limits during cool down: 

For cooldown procedure; the limits for the supports are listed below 

* Radial supports alarm at 65kN; load not to exceed 100kN 
* Axial supports alarm at 5kN; load not to exceed 7.5kN 

If not already done so, please update the spreadsheet (increase version no.) and update your PLC code. 

Regards 

Ruben 


From: "David Kashy" <kashy at jlab.org> 
To: "John Hogan" <hogan at jlab.org> 
Cc: "Ruben Fair" <rfair at jlab.org>, "Renuka Rajput-Ghoshal" <renuka at jlab.org>, "Glenn Young" <gyoung at jlab.org> 
Sent: Monday, May 8, 2017 10:06:44 AM 
Subject: Re: Interlocks 

Hi John, 
My analysis starts with the axial supports with no free travel and with no load at Room temperature. 
As the magnet shrinks during cooldown they become tighter and tighter until the magnet is at 4K 


To have less than 5kN when the magnet gets to 4K the axial supports must start out with extra "slack" so that they only come into contact/tension when the magnet gets to about 120K. Is the design such that we can set them loose by the proper amount to achieve a design tension? Has it been determined how tensioning the Z suports will effect the cold mass alignment? 

Dave 




----- Original Message ----- 
From: "Hogan" <hogan at jlab.org> 
To: "Ruben Fair" <rfair at jlab.org>, "kashy" <kashy at jlab.org> 
Cc: "Renuka Rajput-Ghoshal" <renuka at jlab.org>, "Glenn Young" <gyoung at jlab.org> 
Sent: Monday, May 8, 2017 9:42:00 AM 
Subject: Re: Interlocks 

Ruben, 

As I stated in my email to you, Dave, Bob and Renuka last Wednesday; the axial restraints are not loaded prior to the cooldown and are not designed to take the cooldown load. 

At the start of the cooldown, there is no load on the axial restraints. 

Dave, 

For cooldown procedure; the limits for the supports are listed below 

* Radial supports alarm at 65kN; load not to exceed 100kN 
* Axial supports alarm at 5kN; load not to exceed 7.5kN 

Please let me know if you have any other questions. 

Thanks, 
John 

----- On May 8, 2017, at 7:37 AM, Ruben Fair <rfair at jlab.org> wrote: 

> John, 

> We will need to have the load limit issue resolved with ETI. Could you please 
> push them for this again? 

> I am extremely concerned about the Z support numbers that Dave has calculated - 
> have you managed to review Dave's calcs? If you do not have time (I know things 
> will be somewhat crazy at ETI this week), let Dave know and perhaps we can get 
> Bob Miller, Joe Matalevich or Matt Marchlik to take a look. 

> Regards 

> Ruben 

> From: "David Kashy" <kashy at jlab.org> 
> To: "Renuka Rajput-Ghoshal" <renuka at jlab.org> 
> Cc: "John Hogan" <hogan at jlab.org>, "Ruben Fair" <rfair at jlab.org>, "Glenn Young" 
> <gyoung at jlab.org> 
> Sent: Monday, May 8, 2017 7:06:56 AM 
> Subject: Re: Interlocks 

> Folks, 
> I'm continuing to update the cooldown procedure. 
> I do not have any actual limits listed in the cooldown procedure for allowable 
> loads during cooling. 
> Is there a set? 
> As stated before if the Z supports are snug at 300K they will reach ~7000lbs per 
> the table attached this is more than 3X the fast dump value of 2240 in the 
> table attached. 

> Dave 

> ----- Original Message ----- 
> From: "Renuka Rajput-Ghoshal" <renuka at jlab.org> 
> To: "kashy" <kashy at jlab.org> 
> Cc: "Hogan" jlab.org>, "Ruben Fair" <rfair at jlab.org>, "Glenn Young" 
> <gyoung at jlab.org> 
> Sent: Monday, May 1, 2017 3:57:38 PM 
> Subject: Re: Interlocks 

> Hello Dave, 
> We have given the attached file for load cells interlock values to Pablo and 
> Wesley, but we are still waiting the information from ETI to confirm these 
> numbers. 
> John, do you have any idea when we get these numbers from ETI. 

> Thanks 
> Renuka 

> ----- Original Message ----- 
> From: "Dave Kashy" <kashy at jlab.org> 
> To: "John Hogan" jlab.org>, "rfair" <rfair at jlab.org>, "Glenn Young" 
> <gyoung at jlab.org>, "Renuka Rajput-Ghoshal" <renuka at jlab.org> 
> Sent: Monday, May 1, 2017 3:33:27 PM 
> Subject: Interlocks 

> Hi All, 

> Since I'm working the CD procedure, I was just wondering if we have implemented 
> interlocks on force sensors so during cooldown or powering there are measures 
> in place to keep the magnet safe. 

> Do we have a table of safe range that will be presented at the ERR? 
> Should it be in one of my talks or elsewhere? 

> Thanks 
> Dave 

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