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LED driver primary voltage

sportzcoach

Member
Location
Denver
Occupation
Electrical Contractor
I am hooking up a sign that has an LED driver that is rated 115 volt to 277 volt. I only have 240 volt available. Can I use the voltage even though the rated is a hot and a neutral and I have two hot wires.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
What Hal said. These days, grounded or not doesn't matter, and the voltage range is just that.
 

kwired

Electron manager
Location
NE Nebraska
Occupation
EC
They essentially only take what they need from the incoming AC wave form. You just can't exceed max rated volts or you may have component break down. May even work with input below 120 nominal as long as it can take what it wants to do it's task.
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
See this: https://forums.mikeholt.com/threads...st-not-meant-to-be-used-on-208-or-240.137807/
Would it turn on without letting out the smoke sealed at the factory? yes, at least for the time being. In the long-run and in a large quantity, best to check with factory engineers.

Official answer is likely a no, unless you have a written approval from the factory.

The front-end of ballast is not always "symmetric" and EMI suppression and surge protector component may fail prematurely and internal fuse may only be on the line side where as a symmetric design would have protection on both input leads. It could also lead to RF interference issues.

If a ballast experiences an internal fault, such as a shorted capacitor, it would blow the input fuse, which is in series with the black lead.
If you run it across A and C (both leads at 240v in reference to case) with ground B phase and a fault develops between the case and the the white lead (unfused), it may trip the branch circuit.
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
It says 115 to 277. NOT 115 and 277. If 208 and 240 give it a problem it's a poorly designed product.

-Hal

A computer power supply rated 90-264v for global use (100v +/- 10%, to 240v +/- 10%) are intended for various grounded schemes, but "115 to 277v" ballast does not mean you can use it without regard to the voltage differential between the white and ground.

Here's another example where L-N vs L-L application requires a special design. (so called 60-0-60 balanced power)

120 from 120/240 3W 1ph, 208Y/120 L-N, 480Y/277 L-N, 400Y/230 L-N are all applications with negligible voltage between N-G.
This is why "240" in the US use double pole while 230 in Europe derived from 400Y/230 uses a single pole.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
115 to 277v" ballast does not mean you can use it without regard to the voltage differential between the white and ground.
Sorry. Unless a ballast says do not use on 208 or 240 I have to take 115 to 277 as just that. If there is a problem they all go back to wherever they came from as defective. If a manufacturer designs a product for the US market he has to know what voltages and configurations it might be used with.

-Hal
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
A computer power supply rated 90-264v for global use (100v +/- 10%, to 240v +/- 10%) are intended for various grounded schemes, but "115 to 277v" ballast does not mean you can use it without regard to the voltage differential between the white and ground.
...
Unless the label says the equipment must be supplied by a circuit with a grounded conductor, you can supply it with two ungrounded conductors.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Unless the label says the equipment must be supplied by a circuit with a grounded conductor, you can supply it with two ungrounded conductors.
Is that spelled out in some general UL listing standard that applies to all electrical equipment, or something like that?

Thanks,
Wayne
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Not that I know of, but they have to tell us everything because no one knows what they are doing :D
OK, but if the terminals are marked "L" and "N" that would be sufficient notice that the "N" terminal has to be 0V to ground, yes? Whereas if they are marked "L1" and "L2/N", that would be notice that the device is agnostic on the voltage to ground of the second terminal?

Cheers, Wayne
 

kwired

Electron manager
Location
NE Nebraska
Occupation
EC
OK, but if the terminals are marked "L" and "N" that would be sufficient notice that the "N" terminal has to be 0V to ground, yes? Whereas if they are marked "L1" and "L2/N", that would be notice that the device is agnostic on the voltage to ground of the second terminal?

Cheers, Wayne
Maybe a good concept, don't know how well it is followed or if listing standards take this into consideration.
 

tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
Sorry. Unless a ballast says do not use on 208 or 240 I have to take 115 to 277 as just that. If there is a problem they all go back to wherever they came from as defective. If a manufacturer designs a product for the US market he has to know what voltages and configurations it might be used with.

-Hal
Someone would have to work extra hard for a device to work with 120 or 277, and only those two voltages, and only two terminals, and not terminals for 120 which are separate from 277.

There are too many system voltages between about 100VAC and about 277VAC for anyone to go to the kind of effort needed to not just take the all.

The stuff I work on is designed for 24VAC. Most of us use DC power supplies when working on our benches. A lot of 19VDC laptop power supplies get turned into power supplies for stuff we build.
 
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