sPHENIX discussion of the superconducting solenoid

["Yip, Kin" <kinyip AT bnl.gov>]

Dear Carl,

 

You probably already assumed what I am going to say below.   I went to talk with Tim Costanzo this evening (in his CAS shift this evening).

 

He told me that the 24 V connection was so loose that it could cause problem even when there is no (relatively) violent action of closing/opening the door.  Though there is no way to prove,

Tim agrees that this loose connection could very well be the cause of the two mysterious Watchdog Timer interlocks (=> Magnet trips) that we’ve observed during the 2024 run (~6 months).

 

Richard (CAS) blamed me for not providing him this observation (opening/closing door => cause Watchdog Timer interlocks every time) such that he didn’t know to check about this location of wiring a

few months ago 😅  Well, I wasn’t fully aware of this and didn’t think of its significance because the Watchdog Timer interlock change is not important when we open/close the PS door (as the Magnet is

off, at 0 A).  We asked Tim to check after we/I saw this happened too often and we didn’t understand why this interlock should trip when the PS door closes/opens.

 

Kin

 

From: Yip, Kin
Sent: Monday, October 28, 2024 5:38 AM
To: Costanzo, Timothy <tcostanzo AT bnl.gov>; Rosas, Pablo J <rosas AT bnl.gov>
Cc: Schultheiss, Carl <carls AT bnl.gov>; Karl, Robert F <rkarl AT bnl.gov>; Moloney, John <jmoloney AT bnl.gov>
Subject: RE: sphenix watch dog timer fault

 

Thanks a lot.    I wonder whether this loose connection might have caused problems (like twice in the last 6 months) when you didn't open and close the door ?! 🤔

 

Kin

 

 

-------- Original message --------

From: "Costanzo, Timothy" <tcostanzo AT bnl.gov>

Date: 10/27/24 22:29 (GMT+00:00)

To: "Rosas, Pablo J" <rosas AT bnl.gov>

Cc: "Yip, Kin" <kinyip AT bnl.gov>, "Schultheiss, Carl" <carls AT bnl.gov>, "Karl, Robert F" <rkarl AT bnl.gov>, "Moloney, John" <jmoloney AT bnl.gov>

Subject: sphenix watch dog timer fault

 

Hi Pablo

 

John and I found that the sphenix PS watch dog timer fault was being caused by a loose connection on  the 24VDC (PS #5) din rail. We could see the fault come in when the door was opened and closed. We tighten the din rails screws, and tested, all seems okay now.

I will see you Tuesday.

 

Thanks Tim