D-Sub connectors for high voltage?

[Pimpom]

Are D-Sub connectors suitable for carrying multiple lines of
low-current 230V AC? The idea is to connect up to 10 individually
controlled loads over a 50-foot multi-core cable. The wires are
rated for the voltage. Current levels are sub-100mA.

The cable is to be used only 2 or 3 times a year for a couple of
days on each occasion, to be dismantled and stored in between
each use. On three previous occasions, I used a bundle of twin
wires with individual male plugs at one end and a box with a row
of females at the other, but I'd like to make the whole thing
less bulky and fiddly. (As I've occasionally mentioned in s.e.d.,
I'm in a place where it's not a simple matter of choosing a
suitable connector from an online list and ordering it).

I don't know if there's a universal standard voltage rating for
D-Subs. I've seen one manufacturer's specs of 1000Megs minimum at
500VDC and dielectric strength of 1000V AC for 1 minute. To keep
things simple, forget about mechanical reliability. I have good
soldering experience and could cover each soldered pin with
heatshrink, clamp the wires and provide strain relief. I'm sure
D-Sub connectors will be fine initially, but I'm wondering about
the long-term since they are normally used at much lower
voltages.

 

[Spehro Pefhany]

Are D-Sub connectors suitable for carrying multiple lines of
low-current 230V AC? The idea is to connect up to 10 individually
controlled loads over a 50-foot multi-core cable. The wires are
rated for the voltage. Current levels are sub-100mA.

The cable is to be used only 2 or 3 times a year for a couple of
days on each occasion, to be dismantled and stored in between
each use. On three previous occasions, I used a bundle of twin
wires with individual male plugs at one end and a box with a row
of females at the other, but I'd like to make the whole thing
less bulky and fiddly. (As I've occasionally mentioned in s.e.d.,
I'm in a place where it's not a simple matter of choosing a
suitable connector from an online list and ordering it).

I don't know if there's a universal standard voltage rating for
D-Subs. I've seen one manufacturer's specs of 1000Megs minimum at
500VDC and dielectric strength of 1000V AC for 1 minute. To keep
things simple, forget about mechanical reliability. I have good
soldering experience and could cover each soldered pin with
heatshrink, clamp the wires and provide strain relief. I'm sure
D-Sub connectors will be fine initially, but I'm wondering about
the long-term since they are normally used at much lower
voltages.

There is not the creepage distance (less than 1.5mm?) to meet safety
standards used in most developed countries, particularly when it gets
dirty ("pollution" in the IEC standards).

My unconsidered opinion (which you should not rely upon) is that it
will probably be okay from an electrical pov, but you should pay some
attention to the safety aspects, such as fusing the lines so that the
current rating of the pin (3A or whatever) and the wire going to it
cannot be exceeded, and also make sure that nobody can get shocked.
Higher voltages are actually better from a conductivity pov, since it
will break through oxide layers. They are not better from a safety and
a corrosion pov (ie. if the connector were to get wet and power was
applied). At less than a volt, nothing much will happen, at 5V, bad
things will eventually happen, but slowly, at 230VAC with dirty water,
bad things can happen pretty fast.

 

[Pimpom]

try
http://www.samtec.com
They publish a great deal of useful information at their
website, plus
they even publish third party 'connector resistance'
measurements,
which I've not found at other connector manufacturer websites..

I couldn't access the site. I'll try again later.

 

[Pimpom]

I've used them at 500 volts, no problems. The clearances are
huge on
those old klunkers.

John

Thanks.

 

[[email protected]]

yeh I might be rated for some thing like 500V but it will never meet
any spec for mains voltage

wonder if it is feasible to remove ever other pin in the connector?
or if crimp style just not mount them

You still have the problem of (creepage) distance from pin to shield/ground.
That's still < .100", IIRC.

 

[Spehro Pefhany]

You can get "mixed signal" D-connectors, with fewer pins and holes for
bigger connectors, like high currents pins or co-ax inserts. The
Farnell catalogue devotes a page to parts from FDI and Harting. Not
all that cheap, but sometimes very handy.

http://www.harting-connectivity-net...kverbinder/d-subminiatur-mischsteckverbinder/

Pimpon has mentioned before that he hasn't easy access to a wide line
of products, and is asking about "making do".

If one wants to go with Harting, these connectors are frequently used
for temporary connections to plastic molds (eg. hot runners) and
would be a good choice if one doesn't need military style connectors
and have little in the way of space/weight concerns :

http://www.harting-connectivity-networks.de/en/produkte/produktauswahl/industrie-steckverbinder-han/

They're rugged multiple-contact connectors properly rated and
safety-agency-tested for mains applications. Not particularly cheap.



Best regards,
Spehro Pefhany

 

[Rich Grise]

Are D-Sub connectors suitable for carrying multiple lines of
low-current 230V AC? The idea is to connect up to 10 individually
controlled loads over a 50-foot multi-core cable. The wires are
rated for the voltage. Current levels are sub-100mA.

Don't do it, because someone will plug it into the back of your computer.

Pick almost any other kind of connector for 230VAC.

Good Luck!
Rich