[dsg-svt] FYI: pending SVT support work requests to the DSG

[Brian Eng]

The leak sensor was installed and tested, but we couldn't find a good threshold to set (it only shows up as 3mV when it detects liquid which isn't all that much higher then the noise on that input) so it was put back as disabled after testing.

Then the main SVT chiller failed and it was swapped out with the N2 chiller, which is the last remaining working chiller.

The flow meters were slow to respond when the flow was stopped when first tested, but after the chiller was swapped they appeared to work fine (albeit at -1C instead of the previous -10C). When the valve was closed the flow quickly went to 0 and when it was opened it similarly returned.

The R3S11 HFCB temperature cable was re-terminated. It is working again, but we've seen this before. Only time will tell if it is actually fixed. Hopefully this becomes a non-issue with the new patch panel.

The ambient T2 interlock will require more debugging as it isn't a bad reading, rather despite the reading appearing to be within the limits it still trips the interlock. Since troubleshooting this would require stopping the current running program it was decided to wait until the longer shutdown when the other changes are deployed.

> On Feb 9, 2018, at 8:37 AM, Yuri Gotra <gotra at jlab.org> wrote:
> 
> FYI: the hall is going to restricted access this morning, there is an opportunity to access the system regarding the outstanding SVT requests. Thank you
> 
> On 2/5/18 4:47 PM, Yuri Gotra wrote:
>> Regarding points 3, 5, and 7, most of the day today the hall was in restricted access. There was a good opportunity to fix the reported issues before the RG-A starts.
>> 
>> On 2/5/18 3:43 PM, Peter Bonneau wrote:
>>> See attached DSG response.
>>> 
>>> 
>>> 
>>> On 2/3/2018 10:34 AM, Yuri Gotra wrote:
>>>> The CLAS engineering run is ending in 2 days. We are approaching the start of physics data taking. 
>>>> Here is the list of SVT support work requested from the DSG which is still pending. 
>>>> 
>>>> - Implementing the SVT hardware safety interlocks control interface in CSS, the chosen CLAS environment for slow controls and monitoring. The current LabView version of the interface requires a dedicated MS Windows pc to check the status, monitoring the system state, and resetting the latched interlocks. This pc is not on the CUE management system and requires manual installation of security patches and system updates. 
>>>> - Implementing the hardware interlock alarm logging. Lack of logging features limits debugging options of the primary reasons for interlock actions and delays resolving the alarm incidents. 
>>>> - Broken hardware interlock on ambient temperature T2. This interlock had to be disabled, a detector safety issue. 
>>>> - Failing reading of the inlet coolant temperature in the hardware interlock. This problem requires correct conversion of the raw sensor data at negative temperatures to be implemented. This interlock had to be disabled, a detector safety issue. 
>>>> - Failing reading of the outlet coolant flow meter. An attempt to fix it was made, the reading is still incorrect. This reading provides data to the SVT software and hardware interlocks, a detector safety issue. 
>>>> - Installing the leak detection system. The leak sensor is connected to the hardware interlock but is not yet monitoring the tube connected to the drain pan, a detector safety issue. 
>>>> - Fixing bad connection of the hybrid temperature reading for R3S11B. Several attempts to fix unreliable contact have been made, the reading is still bad. The corresponding module PS interlock had to be disabled, a module safety issue. 
>>>> - Installing the nitrogen cooling line temperature monitoring. The temperature sensor has been ordered. 
>>>> 
>>>> A new request. Anova A40 chiller has issues related to operating at negative temperatures and was removed from the hall this week. This chiller is being tested by the engineering group. The SVT is using one of the Lauda chillers connected to the cold plate. This chiller has a history of blowing the fuses when it was operated in the EEL building. The spare Lauda chiller has 208 V plug. In order to minimize the down time of the detector in case of failure of the main chiller, it is required to assemble a second relay box connected to the hardware interlock. The relay box currently in use was designed for 110 V outlet compatible with A40 and one of the Lauda chillers. 
>>>>