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Isolation level of isolated DCDC module?

Flyback

Well-Known Member
Thread starter #1
Hello,
We need an isolated DCDC module to give 15V output from a 13V input. Its to provide isolated power to a DALI comms bus from a non mains isolated source.
We need full mains isolation. This is usually described as being able to withstand a hi-pot test at “3000VAC at 50Hz for one second”.

The Traco TEN 3-1213 DCDC module gives isolation of “1500VDC for one second”.

Do you think that this is therefore safe to use for our DALI comms bus? (ie, does it equate to full mains isolation)?

Traco TEN 3-1213 DCDC module datasheet
http://www.farnell.com/datasheets/2...086.845751712.1519485949-287702491.1506211291
 

kubeek

Well-Known Member
#2
What kind of isolation do you require? Functional, basic, reinfoced...?
When you decide that, then you should be able to find in the standard what clearance/creepage you require, and somewhere in that standard should also be what test are to be done on that isolation barrier. From that you will see what test voltage is good enough.
 

Flyback

Well-Known Member
Thread starter #3
Thanks, we need the type of isolation that you get from primary to secondary in an offline isolated power supply for eg a domestic product....where human hands might touch the output.

We need "basic" insulation.
 
Last edited:

Flyback

Well-Known Member
Thread starter #5
I think i saw somewhere that dali needs "basic" insulation.
But the DALI specs you get on the internet are appalling....DALI was invented by Tridonic, for Tridonic......thats why its so horrendously difficult to find a clear DALI spec on the web....because tridonic dont want their competitors to know stuff about DALI...........even though its the lighting standard comms protocol of the whole world. Even USA pander to it....instead of having their own.

The following is the best there is..but says nothing about insulation for DALI...
https://web.archive.org/web/20130627012349/http://www.dali-ag.org/c/manual_gb.pdf
 

AnalogKid

Well-Known Member
#6
Thanks, we need the type of isolation that you get from primary to secondary in an offline isolated power supply for eg a domestic product....where human hands might touch the output.
That is "reinforced", not basic.

Because the DC/DC input is not designed specifically mains, it will be hard to find one that is tested and certified for a mains application. Most DC/DC's that are fully certified have high voltage inputs.

To answer your original question - Yes, I think the unit you have will provide adequate insulation. However, while it might pass certification testing (if it has enough design/manufacturing margin), it will not pass an audit.

ak
 

kubeek

Well-Known Member
#7
The document says it is a consortium of manufacturers that use this standard, so why don´t you buy the appropriate specs from them?
Anyway, I agree with AK that you need reinforced if users can touch the comm wires and there is no strict rule in the manual that says to work on it only with power off (and even still it might require reinforced).
 

AnalogKid

Well-Known Member
#8
Neither UL nor the military care about warnings in manuals, or anywhere else. For example, while MIL standards require warning labels in high voltage and high current areas (such as in the power supply area of an electronic system), the labels do nothing to lessen the design requirements to assure operator safety, such as adding insulating or grounded covers/boots/shields, lockout switches, etc.

ak
 

Flyback

Well-Known Member
Thread starter #9
Thanks, in fact, ive dug out a DALI spec which says..

The minimum requirement for system components conformant to this standard shall be basic
insulation as defined in IEC 61347-1.
But we dont have IEC61347-1 and it costs £120.
 

kubeek

Well-Known Member
#10
But we dont have IEC61347-1 and it costs £120.
Well if 120 pounds is too much for an essential standart, then I think the company will go bust very soon. I am fairly certain there are services that for a subscription allow you to look into many standards (all IEC at lest) and that should not cost very much, but then again, if 120 is too much....

But whatever, the number that interests you is, that for 230V supply the test voltage is 4*240V+2000V applied for 1 minute.
 

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