[Dsg-htcc] Back Up Power for Hall B Gas Controls

[Youri Sharabian]

Hi Marc,


The HTCC gas panel (attached to the detector) is equipped with  corresponding Rotameter which is normally closed.

The Rotameter is installed in parallel with Mass Flow Controller  In case if there is a power outage in the hall this Rotameter

has to be open and set to gas flow rate of about 10 l/min. All this has been successfully tested. System experts are responsible

to take all necessary steps regarding HTCC "of mitigating the effects of a massive power outage". I agree with your suggestion

"running the HTCC purge using a Rotameter during the holidays". As Morgan has proposed recently we will switch from CO2

to dry Air after completion of physics run this year and then switch back to  dry CO2 (days before start of next physics run in 2019).

Thank you for bringing attention to the important aspect.


Youri

________________________________
From: Dsg-htcc <dsg-htcc-bounces at jlab.org> on behalf of Marc Mcmullen <mcmullen at jlab.org>
Sent: Tuesday, December 11, 2018 3:29:37 PM
To: dsg-htcc at jlab.org; Morgan Cook IV; Denny Insley
Subject: [Dsg-htcc] Back Up Power for Hall B Gas Controls


Hi Denny,


Yesterday I disconnected the SFL3 Gas Controls from an extension cord and reconnected it to the local utility power outlet. The Gas Controls equipment is on a UPS however that is only meant to last long enough for on-call staff to get on site.


The HTCC is a critical system which would suffer during an outage of substantial time. In the past, I believe the gas supply has been switched over to bypass the MFC in the case of an outage. I am not sure if the bypass circuit is still in service. This is the most efficient method of mitigating the effects of a massive power outage. I strongly suggest running the HTCC purge using a Rotameter during the holidays.


Additionally, it might be a good idea to run an electrical circuit which is connected to generator back-up  to the gas controls on SFL3, FC deck 0, and maybe even the Gas Shed control room.


Regards,

Marc
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