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<p style="margin-top:0;margin-bottom:0">Hi Marc,</p>
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<p style="margin-top:0;margin-bottom:0">The HTCC gas panel (attached to the detector) is equipped with corresponding Rotameter which is normally closed.</p>
<p style="margin-top:0;margin-bottom:0">The Rotameter is installed in parallel with Mass Flow Controller In case if there is a power outage in the hall this Rotameter
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<p style="margin-top:0;margin-bottom:0">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</p>
<p style="margin-top:0;margin-bottom:0">to take all necessary steps regarding HTCC<span> "of mitigating the effects of a massive power outage". I agree with your<span> suggestion
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<p style="margin-top:0;margin-bottom:0"><span><span>"running the HTCC purge using a Rotameter during the holidays". As Morgan has proposed recently we will switch from CO2
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<p style="margin-top:0;margin-bottom:0"><span><span>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).</span></span></p>
<p style="margin-top:0;margin-bottom:0"><span><span>Thank you for bringing attention to the important aspect.
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<p style="margin-top:0;margin-bottom:0"><span><span>Youri </span></span><span></span><br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Dsg-htcc <dsg-htcc-bounces@jlab.org> on behalf of Marc Mcmullen <mcmullen@jlab.org><br>
<b>Sent:</b> Tuesday, December 11, 2018 3:29:37 PM<br>
<b>To:</b> dsg-htcc@jlab.org; Morgan Cook IV; Denny Insley<br>
<b>Subject:</b> [Dsg-htcc] Back Up Power for Hall B Gas Controls</font>
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<p style="margin-top:0; margin-bottom:0">Hi Denny,</p>
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<p style="margin-top:0; margin-bottom:0">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. <br>
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<p style="margin-top:0; margin-bottom:0">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.
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<p style="margin-top:0; margin-bottom:0">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.
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<p style="margin-top:0; margin-bottom:0">Regards,</p>
<p style="margin-top:0; margin-bottom:0">Marc<br>
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