[Dsg-ltcc] LTCC Solenoid Controls Upgrade

[Amrit Yegneswaran]

marc,

thank you very much for the clear explanation of what is going on with the LTCC.


there are a few points i want to clarify.

according to you, the installation work is being done by hall b (lead is bob)

so, i gather that bob would have to address all DA related issues.


on behalf of  DSG, i have the following questions, which perhaps ed or bob could answer you, to avoid confusion later; we have had some with regards to RICH.

  1.  since you are not the DA, does your statement with regards to the pressure system " So, the pressure system will stay intact and unchanged" relevant? doesn't a DA have to say this?
  2.  in other words, must we (DSG) have an official DA statement saying that all is OK for you work on the system?
  3.  can you work on the "control software and control components" in hall b  prior to the DA approving the setup?
  4.  is bob's verbal OK sufficient?


thanks for your e-mail.

sincerely

amrit

________________________________
From: Dsg-ltcc <dsg-ltcc-bounces at jlab.org> on behalf of Marc Mcmullen <mcmullen at jlab.org>
Sent: Tuesday, December 18, 2018 9:58 AM
To: dsg-ltcc at jlab.org
Cc: Patrizia Rossi; Bob Miller
Subject: [Dsg-ltcc] LTCC Solenoid Controls Upgrade


Hi Amrit,



Sectors 3 and 5 of LTCC gas system is in the process of being upgraded to a supply and recovery system (sectors 2 and 6 may be added in the future). Control of the system requires actuation of the supply and return solenoids for the sectors.



We are going to actuate the solenoids using the solid state relay modules installed in the Forward Carriage gas controls system’s cRIO. The cRIO relay modules are rated (1.2 A) close to the steady state current draw of ~ 1 A for the 24 VAC solenoid coils which are currently installed.



To reduce the current draw of the solenoids, we opted to switch to a 120 VAC coil which draws ~0.2 A in steady state.



Due to time constraints (possibility of C4F10 delivery and use) we opted to repurpose the 120 VAC coils recovered from the old sniffer system. I am currently testing the coils to ensure that they work on the bench. We have already fitted 4 coils (enough for S3 and S5) with connectors, after testing is complete we will deliver the coils to Hall B for installation.



Installation requires sliding the current 24 VAC coils off the solenoid plunger shaft and sliding on the 120 VAC version. The solenoid valve body does not need to be removed. So, the pressure system will stay intact and unchanged.



I have attached a diagram which details the flow path of the gas using just S5. Each sector uses a mass flow controller, a supply solenoid and a return solenoid. The solenoids, which will have the coils swapped out, are highlighted in green boxes, they are located in the Hall B Forward Carriage.

The second page is the front panel for the LTCC Solenoid Controls GUI. It depicts the controls for the solenoid valve panel on the Forward Carriage and Gas Shed equipment.



DSG has not made any modifications to the LTCC gas system (mechanical) for this upgrade. We are only dealing with the controls software and controls components. All mechanical installation work is being done by Hall B.



Thanks,

Marc

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