Question about working voltage insulation

[Shiri]

Hey all. I thought I had my build plan finished until the topic of voltage insulation came up. Bridgelux EB strips are rated for 60V and the Samsung Horticulture L2 strips a rating of 59V. But at the bottom of Samsung's spec sheet, it states a maximum of 8 series for the 1ft strips and 4 series for the 2ft strips (max 2 parallel for either sizes).


1 foot
21.5V typ x 8 = 172V

2 feet
43.1V typ x 4 = 172.4V


What's going on here? As far as I understand it the 60V is for SELV but if Samsung has such a high max circuit voltage, is it actually okay to run it higher than 60V?

[Shimbob]

It would be nice if we could get an Electrical Engineer to clarify exactly what they're aiming at with this language because there is some confusion that keeps coming back.

My take on this:
Disclaimer, I am not an EE, I'm a Civil Engr who took more courses than necessary for his degree and enjoyed the extra courses of electric circuits.

First, obviously, electricity can and will arc across an insulator when the voltage is high enough, bad things happen when it does.

I think this language was put in to prevent cases where someone might wire a high, fixed voltage power supply across a single strip. Like a 100V power supply to a LED with 60V-rated insulation. But this is a huge exception and not at all how we assemble LED lights by using LED drivers that regulate their voltage to match what the LEDs want.

In addition, voltages in series...
Say you have 10 LEDs in series, with a forward voltage of 10V each, meaning the total forward voltage is 100V. If you apply 100V to this series and measure the voltage across any one LED, you'll still get 10V. No strip sees 100V, none of the connectors see 100V.

You really have to go out of your way with the wrong type of driver and a single LED to subject that strip to excessive voltage to risk breakdown of the insulator.

[Welight]

.

I think this language was put in to prevent cases where someone might wire a high, fixed voltage power supply across a single strip. Like a 100V power supply to a LED with 60V-rated insulation. But this is a huge exception and not at all how we assemble LED lights by using LED drivers that regulate their voltage to match what the LEDs want.

It should be noted, as I have seen this comment several times.

• Constant Current Led drivers regulate VF

• Constant Voltage drivers do not

It worth pointing this out as many strip builders go parallel on strips with CV drivers, and this is an unregulated power source
cheers

[Shimbob]

• Constant Current Led drivers regulate VF

• Constant Voltage drivers do not

That has not been my experience with putting 36V cxb3590 cobs on a -42 CV driver. Measuring the voltage gets you 35-somethingV, not 42V.

[PeteR_1]

Hey all. I thought I had my build plan finished until the topic of voltage insulation came up. Bridgelux EB strips are rated for 60V and the Samsung Horticulture L2 strips a rating of 59V. But at the bottom of Samsung's spec sheet, it states a maximum of 8 series for the 1ft strips and 4 series for the 2ft strips (max 2 parallel for either sizes).
1 foot
21.5V typ x 8 = 172V
2 feet
43.1V typ x 4 = 172.4V
What's going on here? As far as I understand it the 60V is for SELV but if Samsung has such a high max circuit voltage, is it actually okay to run it higher than 60V?

• Samsung is effectively stating that the Rated Amps / Current (1.2 typ - 1.6 max Amps) can be transmitted by the PCB Electrical Traces and PCB Insulation of up to eight linear ft (8') of their Horticulture L2 Strips (2 strips maximum Daisy Chained, 2.4 typ to 3.2 max Amps).

• Not documented but could be assumed that Samsung LED Strips have IEC 62031:2014 ratings similar to Bridgelux Strips...?

Bridgelux LEDs ,
"This product has been designed and manufactured per IEC 62031:2014.
This product has passed dielectric withstand voltage testing at 500 V [per IEC 62031:2014].
The working voltage designated for the insulation is 60V d.c [SELV Rating].
The maximum allowable voltage across the array must be determined in the end product application."

• Rated per IEC 62031:2014... 60 Vdc designated working voltage...

• Rated per IEC 62031:2014... passed dielectric withstand voltage testing at 500 V

• Maximum voltage across array determined by end user... 'At Their Own Risk'

Copy of an IEC 62031 Test Report (TopWin LED)... http://www.top-win.url.tw/images/IEC62031.pdf

[Shiri]

At my own risk huh So if I wanted to run a CC system but at a lower voltage (still higher than 60V), I would have to do some series/parallel wiring shenanigans? So this build for example:

8x Bridgelux EB Gen. 3 Thrive 5000K 1ft strips (I have an aquarium in mind)
350ma 19.9V
480ma 20.3V
700ma 20.9V
960ma 21.4V (Will never run this high)

Meanwell HLG-120H-C1400
Constant current region 54V ~ 108V
Current adjust range 700 ~ 1400mA

20.9V x 700ma = 14.63w
14.63w x 8 = 117.04 watts total

Four strips across is about 80V and then current is divided in parallel strings so each strip gets 700ma max? I'm basing this off of LEDG's tutorial video, please correct me if I'm wrong. Should I just scrap this plan and go with a CV+CC driver and parallel build instead?

[PeteR_1]

At my own risk huh So if I wanted to run a CC system but at a lower voltage (still higher than 60V), I would have to do some series/parallel wiring shenanigans? So this build for example:

8x Bridgelux EB Gen. 3 Thrive 5000K 1ft strips (I have an aquarium in mind)
350ma 19.9V
480ma 20.3V
700ma 20.9V
960ma 21.4V (Will never run this high)

Meanwell HLG-120H-C1400
Constant current region 54V ~ 108V
Current adjust range 700 ~ 1400mA

20.9V x 700ma = 14.63w
14.63w x 8 = 117.04 watts total

Four strips across is about 80V and then current is divided in parallel strings so each strip gets 700ma max? I'm basing this off of LEDG's tutorial video, please correct me if I'm wrong. Should I just scrap this plan and go with a CV+CC driver and parallel build instead?

Yes, your diagram is a 4-Series / 2-Daisy chain Circuit at 1400 mA Current, effectively four 2 ft strips wired in Series which utilizes the "Series Circuit" benefit, broken DC wire shuts off output power.
[ 4 * 21 Vf = 84 Vdc * 1.4 * 1 circuit = 117.6 Watts max]

To get 700mA max Current you could create 4-Series / 2-Parallel Circuit, 4 Strips in Series and 2 Parallel wired to Driver output has the "Parallel Circuit" liability, broken Parallel circuit increases Amps by 50% to the other circuit (only 2 wired in Parallel).
[ 4 * 21 Vf = 84 Vdc * 0.7 * 2 Circuits = 117.6 Watt max ].

If all 8 strips were wired Parallel with a CV Driver a loss of one (1) strip would only be an Amperage increase of ~ 2% per strip and the Light would still remain On.

MeanWell HLG-120H-C1400A is adjustable by internal pot
MeanWell HLG-120H-C1400B is adjustable by external wired pot

• Parallel Wired = Sum of Amps (individual LED Strip's), Volts remains the same...

• Series Wired = Sum of Voltage (individual LED Strip's), Amps remains the same...

• Watts = Volts * Amps

Refer to the typical 2-Series/5-Parallel Circuit as an example for the 4-Series/2-Parallel Circuit...

[Shiri]

Oh so this segment in the video is wrong then? Time stamp at 26:20.

[PeteR_1]

Oh so this segment in the video is wrong then? Time stamp at 26:20.

Its similar...
In your wiring example a single Series Circuit will provide 1400 mA to the 1st of two 700 mA Parallel/Daisy Chained wired strips (in video 4 Strips Parallel wired)...

In the 2-Parallel Circuit two (2) 700 mA Circuits to four (4) Series wired strips get 700 mA. In this case the Current (700 mA) is split at the driver's output wires, not at the PCB trace of the LED Strips.

[Welight]

• Constant Current Led drivers regulate VF

• Constant Voltage drivers do not

That has not been my experience with putting 36V cxb3590 cobs on a -42 CV driver. Measuring the voltage gets you 35-somethingV, not 42V.

I cant speak to your story as I dont know the details. Im just stating what it is