[Dsg-hallc_nps] NPS HV cabling/connector questions

[Carlos Munoz Camacho]

Dear Brad,

   thanks for the detailed documentation of the several points. I had
misunderstood which SAMTEC connectors you were referring to (I thought you
were referring to the ones attached to the PMTs, and not the ones at the
top of the box).

I will check the safety specs of this with the engineer who designed the
cables and the boards (Thi). Unfortunately he's away on vacations until Aug
17, but I'll get back to you then. All cables and panels are fabricated
now. But if we find a safety issue, we will of course reconsider things.

Concerning the CAD drawing, I can send that to you next week when Emmanuel
will be back at the lab. In the meantime, you could see in page 11 (left)
of https://wiki.jlab.org/cuawiki/images/7/7e/ERR_Calorimeter.pdf a layout
of the boards. The HV is distributed through the flat cables at the top of
the board (and connected to the top of the box). The HV then goes out
through FISCHER connectors on the right side of the PCB board and fed to
the PMT voltage divider through another (smaller) SAMTEC connector (the one
I thought you were referring to). Let me know if you would need more
details (other than a better quality/zoom version of that). I should be
able to provide the routing of the PCB board if you need.

Thanks,
Carlos


On Thu, Jul 30, 2020 at 8:44 PM Brad Sawatzky <brads at jlab.org> wrote:

> Hi Carlos,
>
> Just a few questions to follow up on the SAMTEC connector and long HV
> cable issues.
>
> Just so we're working off the same page, the information I'm going off
> of is noted in these attachments:
>   1. NPS_Cables_Transparents.pdf
>      - See p.6 -- p.8 for the SAMTEC part numbers, and the pin map from
>        the Radiall connector <--> SAMTEC connector group.
>
>   2. SAMTEC-*.pdf
>      - SAMTEC catalog pages for the PMSD cable assemblies, and the
>        discrete IPBD connectors, etc.
>
>   3. NPS_frame_connector_layout.pdf
>      - A simple CAD render of the patch-panel(s) on the exterior of the
>        NPS chassis.
>
>   4. NPS-cabling-inside-chassis_25Jun2019.pdf
>      - CAD render of the interior of the NPS detector chassis
>
>
> The 'PMSD-XX-206-K-D-LUS' called out in [1] are technically complete
> cable assemblies (double-ended, including wire).  AFAICT, the relevant
> discrete connectors are the IPBD units.
>
> Either way, the PMSD and IPBD connectors are only rated to 600 VDC, but
> the production HV is around 1100V.  There is a comment on the SAMTEC
> assembly document that they hi-pot the cable assembly to 1000V as part
> of the QA, so it is *possible* that these parts could be OK, but it'll
> certainly require some kind of safety review, at minimum.  (See
> documents in [2].)
>
> Has procurement and fabrication of the HV patch panel on the NPS roof in
> [3] already begun?  Are we locked into that design, or is there still a
> window to redesign that patch panel around different connectors, if
> needed?
>
> Can you send a more detailed assembly/design model that shows how the
> internal HV connections inside the NPS box are are laid out?  That is,
> some shop drawings or zoomed CAD images that show connections from the
> PMTs to the green panel area in [4], and from the green panel area to
> the interior HV patch panel on the roof (ie. grey cables in [4]).
>
> -- Brad
>
> --
> Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
> Ph: 757-269-5947  -<>-  Fax: 757-269-5235  -<>- Pager: brads-page at jlab.org
> The most exciting phrase to hear in science, the one that heralds new
>   discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/dsg-hallc_nps/attachments/20200730/f4b507b7/attachment.html>