mains isolation distance on PCB - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th March 2005, 10:45 AM   #1
Kram is offline Kram  United Kingdom
diyAudio Member
 
Join Date: Jun 2002
Location: Durham UK
Default mains isolation distance on PCB

Hello

What regulations are there reguarding the use of both mains connected equipment and low voltage (mains isolated) components on the same PCB that are connected with each other by opto isolators and relays.

I think that there is some seperation distance required but I dont know what it is or where to find the details. IEE regulations or CE rules or something like that.

Does anyone know? Im in the UK as well just in case there is any difference between US and UK regulations.

Thanks
Mark
  Reply With Quote
Old 10th March 2005, 10:53 AM   #2
diyAudio Member
 
Frank Berry's Avatar
 
Join Date: Sep 2003
Location: Midland, Michigan
I'm not sure that there are any regulations that pertain to DIY equipment. I think the regulations only apply to equipment that is manufactured for sale.
As a rule of thumb however, I don't like to mix mains voltage on the same board as isolated voltage.
__________________
Frank
  Reply With Quote
Old 10th March 2005, 11:00 AM   #3
Kram is offline Kram  United Kingdom
diyAudio Member
 
Join Date: Jun 2002
Location: Durham UK
Probably should of mentioned that is is for my uni project and therefore has to be correct.

I have to justify every design choice I make. So when I am writhing the report I can say that the PCB confirms to such and such a standard.

Thanks
Mark.
  Reply With Quote
Old 10th March 2005, 11:47 AM   #4
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
If you Google for UK Creepage and Clearance distances I think that will help. IIRC from my brief stint as a small company CE Mark compliance manager/engineer (almost 10 years ago now) that the distance live-earth (for class 1 (earthed)) and live-case (for class 2 (isolated)) equipment is 6mm, so I would presume that it's safe to use this distance for live-lowlevel.

You would be better off researching this properly to make sure you quote the current standard as this will look impressive in your report. I was working to BS-EN60065 back in the day which I believe has now been superseeded.
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more.
  Reply With Quote
Old 10th March 2005, 01:08 PM   #5
Kram is offline Kram  United Kingdom
diyAudio Member
 
Join Date: Jun 2002
Location: Durham UK
thanks richie00boy,

there seems to be some info on what im after on the IEE website but you have to pay for it, DOH!

Anyway im going to see my tutor now so hopefully he will be able to point me in the right direction.

Thankyou
Mark
  Reply With Quote
Old 11th March 2005, 04:06 AM   #6
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
Industry organizations may sell copies of the standards, but it is the government that requires their following. I would suspect the government will provide the specs for free.

Hopefully the Europeans standards are all converging, because there is such an alphabet soup of certifications now. US and UK do indeed have differing standards on many things in this area.
  Reply With Quote
Old 11th March 2005, 11:07 AM   #7
Kram is offline Kram  United Kingdom
diyAudio Member
 
Join Date: Jun 2002
Location: Durham UK
Hello

one of my tutors has suggested that I look at ISO9000 but I will have to search for a relavent answer. Why are things never easy to find

Thanks
Mark
  Reply With Quote
Old 11th March 2005, 11:16 AM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
If can touch anything in the secondary circuit the insulation must be 4000 V and 8 mm creepage distance to the mains side.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 11th March 2005, 11:29 AM   #9
Kram is offline Kram  United Kingdom
diyAudio Member
 
Join Date: Jun 2002
Location: Durham UK
The opto isolators im using to connect between the triac gate and the low voltage side are the MOC3020 and they only come in a standard 6pin dual in line package.

The MOC3020 is mounted in a standard 8 pin socket, so therefor the maximum distance between mains connected parts and low voltage parts is the width of the socket, approx. 8mm.

here is my PCB layout in case anyone can spot anything that is dramatically wrong with it.
Attached Images
File Type: jpg pcb layout2.jpg (48.6 KB, 92 views)
  Reply With Quote
Old 11th March 2005, 11:39 AM   #10
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
There are opto couplers with extended "grid". Just check those types with lot's of approval markings.

BTW: Kram = "hug" in swedish
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Large Distance Optical isolation for DAC. Brian Guralnick Digital Source 23 17th May 2014 05:36 AM
Mains isolation - would this work? woodturner-fran Tubes / Valves 35 5th March 2008 01:33 AM
240Vac mains isolation transformer AndrewT Everything Else 13 26th September 2007 07:10 AM
Mains Isolation 5th element Parts 26 19th June 2004 04:52 PM
Isolation of mains xformers from circuit for headamp Petman Tubes / Valves 1 10th May 2002 02:23 PM


New To Site? Need Help?

All times are GMT. The time now is 07:55 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2