Hello,
Something that's been bothering me ever since I was introduced to AC is that the UL wire ratings don't say what they're for. For example, you'll see 300V rated UL1007/1569 hook-up wire all over the place, but is that for AC voltage or DC voltage?

Thanks!

 

Hello,
Something that's been bothering me ever since I was introduced to AC is that the UL wire ratings don't say what they're for. For example, you'll see 300V rated UL1007/1569 hook-up wire all over the place, but is that for AC voltage or DC voltage?

Thanks!

I believe (and could be wrong) that it is to be understood as the maximum RMS voltage of a sinusoid. Personally, it would make sense to me to rate it at max instantaneous voltage, but they have to keep in mind who their audience is. If you keep your RMS voltages below 300 V, you should be fine unless you have extremely high peak voltages. In that case, either use wire rated for no less than your peak voltage divided by sqrt(2) or look for high-voltage wire, which is more likely to have a peak voltage rating specified.

 

You need to understand just what Underwriters Laboratory is. It is a non-profit USA organization that tests electrical equipment against the National Fire Protection Association's National Electrical Code for compliance with the NEC. They have developed their own American National Standards Institute standards for their internal testing. They also have a for profit corporation that tests for paying customers. This is all based on compliance to NEC code certification of electrical equipment to allow it to be sold to the public and meet insurance underwriter's certifications to limit the legal liability of the company manufacturing and selling electrical devices. The wires that you mention are ANSI standards produced internally by UL for the standardization of their testing methods. The UL standards can be found online if you wish clarification of exactly what the particular standard entails. All electrical devices sold for use in the US must be UL certified. There are several other agencies certifications required in other parts of the world for electrical devices depending on location. It's all about liability and insurability. Don't you just love lawyers...

 

It's all about liability and insurability

So insuring the item is safe isn't a factor?

 

The UL standards can be found online if you wish clarification of exactly what the particular standard entails.

I looked the info up online and I get differing specs from different websites. iq.ul 's site says AC. zgsm-wireharness 's site says AC/DC. ulwire 's site says nothing either way. I could continue...

If it's 300VAC then that should translate to a higher DC voltage rating, and vice versa. Maybe they just put 300V to over-simplify things for non-tech people?

All electrical devices sold for use in the US must be UL certified. There are several other agencies certifications required in other parts of the world for electrical devices depending on location.

Umm, do you know how many Chinese electrical products make it into the US and other countries with no certifications, right? For example, look at the market for circuit board boost or buck convertors.

How do they do this if it's illegal?

Either there's some kind of loop hole, you misunderstood something (I'm hoping), or the US and other governments look the other way when it comes to Chinese suppliers.

It's all about liability and insurability. Don't you just love lawyers...

Only when I become one one...

 

...

Umm, do you know how many Chinese electrical products make it into the US and other countries with no certifications, right? For example, look at the market for circuit board boost or buck convertors.

How do they do this if it's illegal?

Either there's some kind of loop hole, you misunderstood something (I'm hoping), or the US and other governments look the other way when it comes to Chinese suppliers.



Only when I become one one...

You need to look closer, they have a ‘You.L’ sticker.

 

Chinese electrical products make it into the US and other countries with no certifications

Or, counterfeit certifications. If it has a cord set that plugs into a receptacle it must be UL certified to legally be sold in the US. A lot of products I buy from china are not UL certified. Most come with the CE markings for the European Union which is not independently tested but the manufacturer professes it to be safe (much cheaper than what you have to go through to get UL certification). Or CSA marked for the Canadian Standards Association which does test. How the chinese get away with it I don't know but if it doesn't have a cord set and is a component or module apparently it doesn't have to be certified. There might be some reciprocity between UL, CE, and CSA but I don't know. UL and CSA standards are pretty high, not so much CE it seems. I do know that I've seen US made items with multiple certifications so they can be sold in the US and elsewhere. Then there is FCC certification as well... With china coming under the gun now for marketing various cheap handi talkies on many frequencies that do not meet FCC certification standards and are being threatened with sanctions for doing so. You can buy them but unless you have a valid FCC License to operate on those frequencies using them to transmit on those frequencies is illegal. Not to mention that they are so poorly made that they generate a lot of spurious RF signals that violate FCC certification requirements that can get you into violation of FCC laws and enforcement issues for doing so. Lots of issues with chinese designed and manufactured electronics. Other than the US, EU, and Canada, most of the world has no certification requirements.

 

but if it doesn't have a cord set and is a component or module apparently it doesn't have to be certified

I thought it's the opposite. Anything hardwired in a house must be UL certified and it's written in house insurance policies. But anything that plugs in doesn't have to be UL certified.

And no combination of things mentioned is illegal. At max it's civil liability for say selling a product with fake UL listing that causes damages.