240VAC Mains Wire to Board connector - Page 1
Forum section: electronics / projects

author: veryevil
author_rank: Unknown
timestamp: October 23, 2012, 01:09:13 pm
content: Hey, I need to make up a cable assembly which has 5 wires that go to a plug which plugs into a connector only one way round and a complete Muppet could connect up.The cable will have the following:240VAC Live240VAC Neutral240VAC Live Switched240VAC Neutral SwitchedMAINS EARTHThe wires carry very little current (well under an amp) so that isn't the issue.I've been told that I cannot use a screw terminal header or Spade connectors as Muppets might connected the individual wires the wrong way round so it has to be a single connector that is just plug and play.What connectors would you recommend and what is a sensible pin pitch to use for a connector with mains pins together?Thanks Steven

author: ColinB
author_rank: Contributor
timestamp: October 23, 2012, 01:38:30 pm
content: I've seen power supplies use Molex KK-156 connectors for 120Vac, I think they left a missing pin between hot and neutral however, and that's not 240v...

author: SeanB
author_rank: Super Contributor
timestamp: October 23, 2012, 03:50:49 pm
content: Bulgin make a nice range of mains rated multipole connectors. Look at industrial multipole connectors with crimp connections.

author: Bloch
author_rank: Unknown
timestamp: October 23, 2012, 04:05:22 pm
content: I like Phoenix ContactThey have many different connectors. But maybe MSTB 2,5http://eshop.phoenixcontact.dk/phoenix/treeViewClick.do;jsessionid=QG1Zp2GLS9Yyx2SWTn6ckXjBd2GsvLPSdKrZjBlNYhGLSj1gdNYv!529380903?UID=852630759&parentUID=&reloadFrame=true

author: ciccio
author_rank: Frequent Contributor
timestamp: October 23, 2012, 05:26:30 pm
content: You need at least a 7.92 mm (30 mils) pin pitch for 240 V on a PCB connector.The cables cannot be too thin, at least 0.5 or 0.7 mm2, so the crimped contacts cannot be too small.Some regulation may apply to the PE cable size.I use JST VA series connectorshttp://www.jst-mfg.com/product/detail_e.php?series=259(they have only 2 pins) but you can use anything similar , taking care to remove alternate pins (they can supply the connectors without the un-needed pins).Molex too has something similar.Best regards

author: Bloch
author_rank: Unknown
timestamp: October 23, 2012, 06:16:18 pm
content: Quote from: ciccio on October 23, 2012, 05:26:30 pmWhy so long pin pitch ?http://www.goldphoenixpcb.com/html/Support_Resource/prdt/arc_125.htmlandhttp://www.smps.us/pcbtracespacing.htmlQuote62 mils (or 1.6 mm)

author: ciccio
author_rank: Frequent Contributor
timestamp: October 23, 2012, 10:15:55 pm
content: Quote from: Bloch on October 23, 2012, 06:16:18 pmIn fact, you are correct, because referring to UL 60065, figure 10, for 230 V mains (230 + 10% = 253 V x 1.41 = 357 V peak) the minimum clearance or creepage distance between conductors on PCBs results about 1.1 mm.If you consider a pin diameter of 1.7 mm, a suitable pad size can be 2.5 mm (if an oval or rectangular pad is used, this can be the smaller dimension), so with a 3.96 mm pitch connector you get a 3.96 - 2.5 = 1.4 mm creepage distance, very close to the limit.A 5.08 or 5.0 mm pitch connector could be used, but most people prefer to use the lower cost 3.96 mm pitch without a pin, resulting in 7.92 mm pitch.Please look inside any consumer electronic product: you'll see JST VA connectors everywhere, expecially on single sided boards, where mechanical strength requires larger pads.Best regards

author: veryevil
author_rank: Unknown
timestamp: October 24, 2012, 07:31:46 am
content: Hey, thanks for the info. The JST VA series isn't availiable from Farnell, RS, Digi-Key or Mouser which is annoying and it also is only 2 pins.I did find these connectors on Farnellhttp://uk.farnell.com/jsp/level5/module.jsp?moduleId=en/353567.xmlwhich have a 6.35mm pitch. I could use a 3 pin and a 2 pin header and separate the switched mains signal.I guess I could use these with a 4.2mm track and 2.15mm clearance, Yes / No?Any other suggestions welcome!

author: ciccio
author_rank: Frequent Contributor
timestamp: October 24, 2012, 10:33:34 am
content: Quote from: veryevil on October 24, 2012, 07:31:46 amYes, you can be sure that any safety regulation is respected.Speaking of creepage distances, I have a story for you:The assembler finished his stock of standard solder wire, and being Saturday and an a schedule, he bought some "no name" wire from the local hardware store.He soldered about 100 relays on the boards of the temperature controllers we were manufacturing, and the units were tested and put in the burn-in room, with mains connected to the relays.After about 12 hours a terrible smell was felt in the lab: the flux in the "hardware" solder was conductive, and mains a.c. was passing between the pins of the relays, and the there was enough heat dissipated to burn the fiberglass of the PCB.Small creepage distances need a very clean board..Best regards