AC Voltage on 0-10V wiring

[Bayoubushmen]

Hello, I know there have been a number of 0-10V questions and discussions but, I could not find any that dealt with what I am experiencing.

I recently installed a number or LED can retrofits with 0-10V dimming. I noticed (by being shocked) that there was 65VAC and 44VDC to ground on the purple and grey 0-10V wires coming out of the fixture when the fixture was on. There was <18VDC between the two purple and grey and they did dim until I shorted them to ground producing and arc. Now they will not dim. The manufacturer of the fixture is telling me that is normal.

Do any of you have any experience or understanding on this issue that you could share? Thank you in advance.

 

[gar]

181015-2028 EDT

Clearly it is a badly designed fixture. Cheap.

.

 

[Bayoubushmen]

181015-2028 EDT

Clearly it is a badly designed fixture. Cheap.

.

Yeah. I just can't find any documentation that shows that is not acceptable. I am having to prove my case to the manufacturer. Any guidance on where to look. I know its not proper but, how to prove its not proper?

 

[GoldDigger]

Yeah. I just can't find any documentation that shows that is not acceptable. I am having to prove my case to the manufacturer. Any guidance on where to look. I know its not proper but, how to prove its not proper?

As a first issue, I would expect that the incidental voltages on the dimming wires are inconsistent with it being legitimately designated as a Class 2 limited power circuit. And if it was not listed as a limited power circuit it probably would not meet standard architectural specifications.

Sent from my XT1585 using Tapatalk

 

[Bayoubushmen]

As a first issue, I would expect that the incidental voltages on the dimming wires are inconsistent with it being legitimately designated as a Class 2 limited power circuit. And if it was not listed as a limited power circuit it probably would not meet standard architectural specifications.

Sent from my XT1585 using Tapatalk

Yes, I was thinking about that. The fixture has the power conductors and the low voltage dimming conductors together in an mc cable whip. Would that make it class 1? And then I wouldn't be able to just run plenum rated 18/2 above the suspended ceiling like i planned?

I am curious if anyone is aware of 0-10V standards for drivers and fixtures that are violated here. And, please if you have any other thoughts as well.

 

[hbiss]

I have never seen any specs but I will bet that the dimming conductors are supposed to be isolated from the power in order to be listed. Is there any listing mark? I would just return them from whence they came for a refund and use something of better quality.

-Hal

 

[Bayoubushmen]

I have never seen any specs but I will bet that the dimming conductors are supposed to be isolated from the power in order to be listed. Is there any listing mark? I would just return them from whence they came for a refund and use something of better quality.

-Hal

Unfortunately, it’s not that easy. There are (88) installed in a school cafeteria. They were purchased by the customer. I appreciate your input, but I need to find an answer to the question I posed. Hopefully someone will have some insight into this issue.

In my researching, I have read that a number of manufacturers have induced AC voltage on the low voltage wires. I’ve seen some manufacturers’ troubleshooting guide that says that if AC voltage is over 2V, there is an issue. I am looking for a standard that I can compare their product against. I found where IEC standard 60929 Annex E is the standard they should be designed to but I cannot find that online and the IEC wants hundreds of $ for a copy.

 

[gar]

181016-0959 EDT

Bayoubushmen:

Tie the negative wire of the 0=10 V circuit to EGC.

If no fireworks, then problem is solved. Otherwise send the damaged lights back for a refund.

Actually first take a 10,000 ohm 1/4 watt resistor and place it between the negative 0-10 V wire , and EGC. If the resistor is destroyed, then try a 10,000 ohm 5 W resistor, and measure the voltage drop across the resistor. This will allow you to calculate current.

.

 

[gar]

181016-1154 EDT

To have an induced voltage in something that something has to be a closed conductive coil of some form, and there has to be a magnetic field whose flux lines cross that coil. In the limit that coil can be a hunk of iron with induced eddy currents, no explicit coil. Or it can be a large explicit coil of conductive wire.

The more open a coil is the more flux linkage, and the greater is the induced voltage.

Two closely spaced parallel wires with equal current but opposite direction tend to cancel each other's field external to the wire pair.

The induced voltage in a loop has no particular relationship to something like earth. A voltage from a loop to something like earth has to have some other driving force.

If I have an open loop and tie one end to earth, and induce a voltage in that coil, then the other end will have a voltage relative to earth.

.

 

[hbiss]

They were purchased by the customer.

Ok, so how is this your problem? Write up a report of your findings and submit it to the customer. Be sure to include that "this serves to put you on notice that serious defects have been found with the fixtures supplied by the school and you will not be responsible for injuries or damages arising from their use".

-Hal

 

[Strathead]

Unfortunately, it’s not that easy. There are (88) installed in a school cafeteria. They were purchased by the customer. I appreciate your input, but I need to find an answer to the question I posed. Hopefully someone will have some insight into this issue.

In my researching, I have read that a number of manufacturers have induced AC voltage on the low voltage wires. I’ve seen some manufacturers’ troubleshooting guide that says that if AC voltage is over 2V, there is an issue. I am looking for a standard that I can compare their product against. I found where IEC standard 60929 Annex E is the standard they should be designed to but I cannot find that online and the IEC wants hundreds of $ for a copy.

I think it is likely that someone wired a fixture up wrong and you have AC wiring hooked to 0-10V It happened on one of my jobs. The Luminary MC is a listed assembly so the Class 2 wires are separated from the line voltage in compliance with the NEC, basically the jacket is listed NM or UF. The terminations need to be done in a separate box or outside the junction box, however.

 

[Bayoubushmen]

0-10V dimming driver standards

0-10V dimming driver standards

I really appreciate y'all's comments. However I was hoping someone would have an answer to the question I posed, basically: "What industry standards are there that describe the proper function and parameters of a dimming 0-10V driver?"

I understand that legally, I am not "on the hook" with the customer since I didn't purchase or choose the fixtures but, I am in a better position to hold the manufacturer accountable than the customer (who has zero electrical understanding.) Whether it is me or the customer that battles it out with the manufacturer, I desire to understand the situation and standards that have a bearing on this problem. If you don't have a specific answer to my question, that is ok. Thanks for being interested.

 

[hbiss]

I found where IEC standard 60929 Annex E is the standard they should be designed to but I cannot find that online and the IEC wants hundreds of $ for a copy.

Does the product actually have an IEC label? If not, saying they should be designed to some standard is meaningless. There is lots of cheap Chinese junk sold here that is not listed or is fraudulently marked as listed.

... I am in a better position to hold the manufacturer accountable than the customer (who has zero electrical understanding.)

Hold the manufacturer responsible? Good luck with that. The only one responsible here is your ignorant customer who only understood that purchasing the product themselves would save a few dollars. If they refuse to understand what you are telling them why are you banging your head against the wall? They don't care, why should you?? Surely you must have things to do that will make you money.

-Hal

 

[Bayoubushmen]

Does the product actually have an IEC label? If not, saying they should be designed to some standard is meaningless. There is lots of cheap Chinese junk sold here that is not listed or is fraudulently marked as listed.



Hold the manufacturer responsible? Good luck with that. The only one responsible here is your ignorant customer who only understood that purchasing the product themselves would save a few dollars. If they refuse to understand what you are telling them why are you banging your head against the wall? They don't care, why should you?? Surely you must have things to do that will make you money.

-Hal

Hal, thanks for your comment. I care about my customer. They do not understand electrical matters - that is why they hired me. My relationship with this customer began after the fixtures were purchased. They trust that what I am telling them is the truth. Again, its not about my legal responsibility. I could walk away with no repercussions. It would on the distributor and the end user to fight it out with the manufacturer. I would like to assist the customer in this for multiple reasons. One, I want to understand this problem better. I worked previously as a lighting rep and I understand that it is not always as simple as "its a Chinese piece of junk". Almost all LED lighting comes from China. Even the big names. Most of the time, you can buy the exact same fixture from a "no name" brand that you can from a "big name" for less. The biggest difference is that the "big name" brands will usually stand behind it. Some are pieces of junk. This is one I think. Two, between the distributor, customer, and honestly the manufacturer (importer) - I understand the problem better than any so, I am going to stay engaged to try and help bring about a fair conclusion. Three, If I stick with the customer through this and help them get a positive conclusion, they will be my customer for life.

If it irritates you that I am trying to help my customer in a capacity that isn't legally required then you can just move on to the next post.

 

[hbiss]

I do understand what you are trying to do for your customer and, no, it doesn't irritate me. What I'm trying to say is that I think you are wasting your time because you will get nowhere with this. As you said, if it was a "big name brand" you would have a good chance of a resolution. But look at what you are dealing with here. All the distributor will probably do is replace the products that you say are defective with another of the same thing. Beyond that they have no leverage or even communication with the manufacturer regarding design issues other than threatening to drop them. This is a manufacturer that is selling unlisted products so what does that say about how much they care? The bigger question here is what do you want the manufacturer to do?

Now, if you could convince the distributor to replace all those retrofits with something from another manufacturer I'll say job well done.

-Hal

 

[Bayoubushmen]

These were purchased from a manufacturer that is US based. They really just import from China but, they have an interest in continuing to sell their product in the US to my distributors and others. The distributor is returning the bad fixtures and we are buying some from another manufacturer. I want this manufacturer to pay for my labor to change them back out. The customer has paid me to install them initially but, I do not think it should be on them or myself to change them out this time. It should be on the manufacturer that sold us the bad fixtures. I want them to pay my labor bill. I believe that they should. I have been a lighting factory rep for the last 6 years and I have seen it done. That may go nowhere and that is fine and almost expected. Really, at this point I am curious to know exactly what the parameters of a properly functioning 0-10V dimming ballast are. I understand there is a 10V differential between the purple and gray wires at 100% and 0V at off. What is the proper DC Voltage to ground? What is an acceptable AC voltage to ground since some leakage or induced voltage is common? That is why I am trying to find some industry standard here.

 

[hbiss]

The only way you are going to find that out is to pay money for the UL (or IEC) standard- as you already know.

-Hal