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Connectors for 200V dc

davidwalker2
I have an installation that uses 200V dc (balanced about earth but not earthed). All the installed equipment is direct wired, but I have an application that needs a plug and socket.  I don't want to use the standard connectors that are also used for ac to avoid ac equipment being plugged in inadvertently.  The equipment in question will draw a current around 8 amps and is metal framed, not double insulated so needs an earth.  I would be grateful for any suggestions/ advice.


I am sure that this has been discussed previously, but I cannot find it on the old forum.


Many thanks,


David
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    No ... but perhaps difficult to get hold of ... although I'd guess not impossible.
  • 0
    You obviously have not been in some of this forum members sheds.
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    Sparkingchip:

    You obviously have not been in some of this forum members sheds.




    I have a couple in mine, so guilty as charged ?

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    AJJewsbury:

    I guess the "correct" answer (according to standards) is a BS EN 60309 2 pole + PE connector with the earth at the 3h position (in white) -  which is specifically for 50-250V d.c. Where you'd source such as beast from I've no idea though (I don't recall ever seeing such a thing even in a catalogue never mind real life).




    MK list K9203GRY sockets and K9003GRY plugs. Presumably they will know where you can purchase them.

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    Again, many thanks for your interest, I had not expected to get such a generous response.

    As Mike guessed this is a museum, Kempton Steam Museum http://www.kemptonsteam.org .  The original 1928 installation was 200Vdc from a local generator, then from the mid-1930’s, ac from the grid and dc from mercury arc rectifiers.  So, we have a mix of ac and dc and as mentioned various wiring standards, no dc plugs and sockets and the ac distribution uses standard “modern” industrial standards.  We are charged with maintaining the heritage installation as installed subject to current safety regulations and if not, it has to look authentic (where on view, modern CU’s in dummy “cast iron” enclosures for instance).

    This particular requirement will be within a restricted access cage not accessible to the public.  The outlet does not have to be switched and will not be unplugged with power applied (any access will be in proximity to the bus-bars and if powered would be live working and subject to the Regulations).  I need to provide a base load of about 6 - 8amps for the rectifiers to stabilise the low current output voltage and would prefer it not to be hard wired.


    David

    My concern was to use something appropriate preferably an approved standard.  The problem is white CEEforms do not seem to be available.

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    Thanks for the MK information Chris, I will pursue that after the holiday.


    David
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    It was not a guess - we have had a thread on the old forum about the 'soft start' of the transformers for the rectifiers on the old forum, and another about the use of perspex shields to limit the approach of visitors to a potential source of UV.

    If this connector is in a cage, and is only unplugged when the power is off, then you may as well treat it as if it is inside a piece of equipmetn, and  life gets a lot easier

     go for buccaneers...


    rated for up to 277V AC or DC and about 10A for the 3 pin version.

    https://uk.farnell.com/bulgin/px0731-p/circular-connector-plug-3-way/dp/314195

    https://uk.farnell.com/bulgin/px0765-s/socket-low-profile-3-pole/dp/978012?MER=sy-me-pd-mi-acce


      do be aware there are plug and socket versions of the reverse sense as well, so you could also have pins on the box, holes on the end of the cable - versions with more or less pins exist too, we have used the 4 pole ones on equipment instead of an IEC inlet, with a 4 core  power lead, when we wanted to not liven up until after a pilot to  earth loopback was complete.

    In any case, all connectors in that series are rated for DC, so long as non-breaking under load, and are definitely not going to be confused with anything else.



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    Yes, I was just making it clear that even a plug purchased after 1999 would be "AC only", therefore there's not simply a need to look for a vintage switched socket-outlet, but also a pre-1999 plug !



    Presumably newly manufactured plugs/sockets to BS 546 are permitted to exceed the minimum standards set down in the BS - so there might be a possibility of finding modern ones whose manufacturer was happy to state that they were also suitable for d.c. use. Presumably pre-1999 ones should have been suitable for d.c. and so unless the manufacturer's design had changed significantly in the meantime, it seems likely that current production will be equally suitable in practice, even if the BS no longer stipulates so.


    Although I admit that the old fashioned brown ones might look more in keeping.


       -  Andy.
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    Yes, Mike , I do remember the thread, and have posted several others when it seemed useful to have an opinion on unusual situations from the expertise here.  Thanks for the suggestion of the Buccaneers, which look ideal in this situation.


    David
  • Former Community Member
    0 Former Community Member
    The exciter electrodes should keep the MAR stable but I agree with you a small load will keep the output voltage in check. I can’t help thinking that as you have the switchboard why not use a hard wired load. There is an American company that still makes DC knife switches, I’ll try to find them if you want.

    BTW, I don’t recommend standing in front of an open frame 440V DC breaker when it trips @1500A. Fireproof overalls have there uses.

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