[Dsg-hallb_magnets] Solenoid trip - comments/questions

[Brian Eng]

Attached is the schematic that Carroll Jones provided.

There's no indication as to what the PVs are for some of the readouts, but at least it's something ...

----- Original Message -----
> From: "Amrit Yegneswaran" <yeg at jlab.org>
> To: "dsg-hallb magnets" <dsg-hallb_magnets at jlab.org>
> Sent: Monday, November 26, 2018 6:48:36 PM
> Subject: Re: [Dsg-hallb_magnets] Solenoid trip - comments/questions

> hello pablo,
> very good questions and conjectures.
> i appreciate the fact that dsg is trying to understand the issue along with msg.
> with regards to your e-mail: my answers and comments are, in-line in blue.
> 
> Have we heard anything about the lcw:92_Flow_Makeup signal?
> i guess it is not a state secret, so i can't understand that in the lab which is
> at the frontier of nuclear science , no one know what this signal about.
> i think that this signal as the name suggests, indicates flow makeup , i.e. if
> for some reason the flow is reduced, say for instance due to back pressure,
> flow is increased to maintain the steady state rate.
> 
> Does anyone know what are the units for this signal?
> now this is embarrassing, really and truly.
> i am basically dead against plots with no units along the axes and no
> grid-lines, but i guess if one knows the units one could suppress it, to save
> cyber ink!
> bottom line, in a third world country like india, where i hail from, the school
> system would not let a third grader get away with this.
> 
> It seems like during normal operation of the Solenoid at 2416 A, the recent
> pressure transducers installed on 11/12/2018, displayed a normal water return
> pressure (B_LCW_Level1_Ret) into 42-50 psi range, and water supply pressure
> (B_LCW_Level1_Sup) into 115 - 117 psi. When the Solenoid tripped
> B_LCW_Level1_Ret increased to ~ 60 psi, and B_LCW_Level1_Sup was mostly stable.
> (See attached myplot)
> very well observed.
> does an increase of 20% in the return pressure, trigger some unknown interlock
> or reduce the flow below threshold, that the trip occurs?
> i thought brian, you , et.al did some adjusting of the flow-meters fs1-fs4 (i
> think).
> i recall, i asked in a previous e-mail whether the flow was calibtrated, to
> which brian responded " no".
> so what if we are flowing a trickle and the back pressure increases and the flow
> stops?
> we should know how much we are flowing, isn't plant services the keeper of the
> books?
> 
> Maybe this lcw:92_Flow_Makeup signal is showing the amount of water flow to make
> up and keep the supply water flow stable.
> Since the water return is greater than the max increment (~5 xxx units) of
> lcw:92_Flow_Makeup, this water flow compensation can only handle the enough
> supply water flow for ~ 10 min and then just give up.
> Could be some valve being opened (right at that time), which is part of the same
> Solenoid water return loop?
> excellent, see my earlier responses.
> 
> now, dear dsg illuminati (brian, peter, amanda, tyler, pablo, george, marc) who
> are deeply involved in in assisting the magnet operations endeavor, i would
> very much like you to contact plant services, (yes, yet again and again and
> again), try and get a diagram/schematic of the lcw-92 sensor and location (
> george/marc could do this); i was informed that doug tilles knew where such
> drawings were hoarded, so that we can have a reasonable discussion on
> wednesday!
> 
> something about this saying "a blind man chasing a black cat, in a dark room"
> seems to reflect our current situation, but then again we can be the masters of
> our fate.
> yeah yeah ignorance is bliss and all that, but i hate it.
> we should get on this issue and figure it out, i know we can.
> memorare: morte prima di disonore
> 
> goodnight and god bless
> 
> 
> 
> 
> 
> 
> 
> From: "Pablo Campero" <campero at jlab.org>
> To: "dsg-hallb magnets" <dsg-hallb_magnets at jlab.org>
> Sent: Monday, November 26, 2018 5:22:31 PM
> Subject: [Dsg-hallb_magnets] Solenoid trip - comments/questions
> 
> Hello,
> 
> DSG has been discussing the last solenoid trip occurred on 11/25/2018. We have
> the following comments/questions:
> 
> Have we heard anything about the lcw:92_Flow_Makeup signal? Does anyone know
> what are the units for this signal?
> 
> It seems like during normal operation of the Solenoid at 2416 A, the recent
> pressure transducers installed on 11/12/2018, displayed a normal water return
> pressure (B_LCW_Level1_Ret) into 42-50 psi range, and water supply pressure
> (B_LCW_Level1_Sup) into 115 - 117 psi. When the Solenoid tripped
> B_LCW_Level1_Ret increased to ~ 60 psi, and B_LCW_Level1_Sup was mostly stable.
> (See attached myplot)
> 
> Maybe this lcw:92_Flow_Makeup signal is showing the amount of water flow to make
> up and keep the supply water flow stable.
> Since the water return is greater than the max increment (~5 xxx units) of
> lcw:92_Flow_Makeup, this water flow compensation can only handle the enough
> supply water flow for ~ 10 min and then just give up.
> Could be some valve being opened (right at that time), which is part of the same
> Solenoid water return loop?
> 
> 
> Best Regards,
> Pablo
> 
> 
> 
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