UL certification - 30V vs 48V
UL certification - 30V vs 48V
(OP)
Not sure if this is the right forum, so let me know if there is a better one. For low voltage systems, typically 48VDC and under, the UL certification is much different than 120VAC of course. But the question I have, I was told in a conversation the other day that its easier to have a system pass UL where 30V is being distributed over a cable, rather than 48V. He said..somewhat to quote "30V UL intrinsic is much easier to pass than doing it at 48V". Now I think of intrinsic as being in a Class/Division where sparks must be suppressed for reduction of energy that could cause an explosion. This thing is a consumer type application so it didn't make any sense to me. Looking for comments.
Thanks
Thanks






RE: UL certification - 30V vs 48V
RE: UL certification - 30V vs 48V
I believe 42V is a cut off voltage where electrocution becomes more likely so 48V may be tougher than 30V in that regard. I could be wrong on this too.
What kind of device are you trying to UL? Maybe we can provide more guidance.
Keith Cress
kcress - http://www.flaminsystems.com
RE: UL certification - 30V vs 48V
RE: UL certification - 30V vs 48V
Have you ever herded a product through UL?
Keith Cress
kcress - http://www.flaminsystems.com
RE: UL certification - 30V vs 48V
RE: UL certification - 30V vs 48V
A lot of times the easiest and fastest route is to use a testing house - not UL directly. It can cost a little more but save you months! They can often quickly answer questions like this for you. I'd call up a testing company and enquire about their services and then your specific voltage question.
Be interested to hear the result too.
Keith Cress
kcress - http://www.flaminsystems.com
RE: UL certification - 30V vs 48V
I will ask about the voltage tho, just as a matter of curiosity.
RE: UL certification - 30V vs 48V
This is only my gut-level opinion, but I think the maximum 30VACrms—42.4VDC/ACpeak was revised [maybe a half-dozen editions ago] in the National Electrical Code to 30VACrms—42.4VACpeak—60VDC; at the behest of the telecommunications industry via IEEE.
Telecomms have routinely used variously sized nominal-“48VDC” battery sets—where [don’t quote me on this] battery-charger “float” voltage may be 53VDC and “equalize” voltage may be 56VDC…with their [internally] acceptable track record.
RE: UL certification - 30V vs 48V
Keith Cress
kcress - http://www.flaminsystems.com
RE: UL certification - 30V vs 48V
We use ETL (Intertek) they seem much better at interpreting UL's specs than UL people do. It can cut months off your actual testing time. With UL we end up spending time/money just to prove to them that they are applying their standards incorrectly. Its a joke. Last time (before me switched to ETL) for comparison we sent the same product through 2 different UL offices and both came back with completely different areas that we "supposedly" didn't follow the specs. None of them were correct.