I have an RA-87 loop supply that I’d like to resurrect but am having difficulty with the DC loop power connectors.  They are Hubbell “Twist-Tite” female receptacles as seen in the attached photo.  The diameter across the outer edge of the prongs is exactly 5/8”.  I’m not a “Hubbell guy” … but I’m trying to learn!

TT 11-957 documents the RA-87 (see: https://archive.org/download/TM11-957/TM11-957.pdf), where Section V “Supplementary Data” references Stock No. 6Z7815, described as “Hubbell #9213 Twist-Tite”.

I’ve failed to cross-match this to modern production.  For future reference, here’s what I found (and where):

https://hubbellcdn.com/ohwassets/HCI/WiringDevice/media/NEMA_Chart.pdf suggests that perhaps these would match to “L1” connectors (2 Pole / 2 Wire, 125V 15A) – thus HBL7540-like (which is a duplex receptacle).  In the https://www.lockingpowercords.com/images/file/Hubbell%20Twist%20Lock%20Plugs.pdf catalog, which doesn’t include prong-related dimensions, it appears that HBL7498 is the corresponding single panel-mount receptacle (page B-3), HOWEVER none of the photos there show the polarized receptacle opening  – although the schematic illustration at the top of the page suggests that there should be one.

https://www.westwayelectricsupply.com/buy/product/HBL7498/PDW~6710722 does include a detailed photo of a receptacle that appears to include a definite polarized opening like mine.  But I still can’t tell whether the prong-spacing corresponds!

https://www.westwayelectricsupply.com/buy/product/HBL7545C/112369 appears to show the sort of marked angle-bend in the polarizing prong that I expect from my RA-87 sockets.  But I still can’t tell whether the prong-spacing corresponds …  even on the spec-sheet: https://images.tradeservice.com/OA2QNPBKZAEURZ8S/ATTACHMENTS/DIR100323/Hubbell-WiringDeviceKellems_08094_1_SPEC.pdf

Digging some more (are we having fun yet?), I looked at the NEMA standard: https://archive.org/download/NEMA-WD-6-2016/ANSI-NEMA%20WD%206-2016.pdf and found page 64 (72 of 153 in the PDF) which tells-the-tale.  Radius to prong midlines is 0.343” and prong thickness is 0.060”, therefore the diameter across the outer edge of the prongs is 0.746”.  Which is definitely wider than the 5/8” that I measure on the RA-87 Twist-Tite receptacles.

This discrepancy makes me think “midget”, but those are polarized by difference in prong length (do not have an angle-bend) and the diameter across the outer edge of the prongs is only 0.496”.

I can’t find any “Twist-Tite” documentation, but there are these two items currently on eBay: https://www.ebay.com/itm/402888148334 and https://www.ebay.com/itm/233454627504

I’ve concluded that there is no modern equivalent to the Hubbell “Twist-Tite”; am I right?

Does anyone have a matching Twist-Tite male plug, or two, in their spares collection that can be “freed” to fit my RA-87 application?

Thank you,

paul

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