Led power supply

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karn

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I have a LED fixture with a GE LED power supply model number D150HP52X70V1SM, input 347-480 V~, 60Hz, Iin max 0.6A~, PF min 0.9, and labled for the output is 120-280V, Iout 0.525-0.7A, Pout 150W,

I'm trying to run the fixture from a 240v service, could I just do away with the power supply and run 240 into the fixture? Or does the led power supply do something else? Also If needed is there a recommended power supply to use?

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karn

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That and I'm not really sure If the output is ac or dc, it doesn't really specify, but I could probably always get a rectifier or something if needed
 

gar

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180224-1658 EST

karn:

From the limited information you provided the power supply (driver) is probably an approximately constant current supply, and probably DC output.

No idea about your LED light.

You electricians are going to have to learn how things work, how to analyze circuits, and run appropriate experiments.

Assuming you have an appropriate DVM, and some other components like small incandescent bulbs you can run experiments on your power supply to figure out its characteristics. Likely it is DC, easy to figure out.

You need some knowledge about LEDs, then you might be able run some experiments on the bulb.

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karn

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The extent of my experiment was feeding the fixture with 240v, it instantly turned on, I was more concerned with long term effects of running the power supply in 240v when it's wanting 347-480, but other than that it seems to work fine on 240
 

GoldDigger

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The extent of my experiment was feeding the fixture with 240v, it instantly turned on, I was more concerned with long term effects of running the power supply in 240v when it's wanting 347-480, but other than that it seems to work fine on 240

The one thing that you can be relatively sure of is that the input components (diodes, switching transistors, or whatever) will be carrying twice the current to get the same power on the output side going to the LEDs. Only the manufacturer knows whether they can handle that double current or not. Long term thermal damage to semiconductors is quite possible even though they may appear initially to work fine.
 

gar

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180224-2036 EST

karn:

Now that I see GoldDigger's response and have reread your original post I am confused.

I understood you to have a separate power supply from the LED fixture. Is that correct?

The power supply is rated 347-480 for input volts, but the output rating is 120-280V, Iout 0.525-0.7A, Pout 150W. (The constant Pout does not make sense.)

With this wide an output voltage range, and as small an output current range, I am guessing the power supply is somewhat of a current source rather than a voltage source. This is what you would want to drive LEDs with, if the LED fixture, whatever it is, did not internally control LED current.

If current limiting is not controlled within the LED fixture, then you don't want to power the LEDs from a constant voltage source.


The extent of my experiment was feeding the fixture with 240v, it instantly turned on, I was more concerned with long term effects of running the power supply in 240v when it's wanting 347-480, but other than that it seems to work fine on 240
Did you feed the fixture, meaning the LED assembly without the power supply, with 240 V 60 Hz or the input to the power supply? The above comment does not seem consistent with your first post.

If you are talking about 240 V into the power supply when its lower voltage rating is 347 V, then that is a no-no.

.

 
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gar

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karan:

Look at what GoldDigger described about running low voltage into a switching power supply with a constant output load power.

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gar

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180225-0843 EST

karan:

Using 347 V, 0.6 A, and 0.9 PF the actual input power is about 347*0.6*0.9 = 187 W for 150 W out or an efficiency of 80%. Seems reasonable.

As a ballpark figure we can guesstimate at 150 W output from the power supply and 240 V input to the power supply that the input current to be about 0.6*347/240 = 1.44 A. Way over its rating.

You may not have a 150 W load. When you operate the LED in combination with the power supply with 240 V into the power supply what is your measured current into the power supply? Should use an RMS ammeter, but at a PF of 0.9 an average reading meter may be adequate. A Fluke 27 is average reading, and an 87 is RMS.

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karn

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180225-0843 EST

karan:

Using 347 V, 0.6 A, and 0.9 PF the actual input power is about 347*0.6*0.9 = 187 W for 150 W out or an efficiency of 80%. Seems reasonable.

As a ballpark figure we can guesstimate at 150 W output from the power supply and 240 V input to the power supply that the input current to be about 0.6*347/240 = 1.44 A. Way over its rating.

You may not have a 150 W load. When you operate the LED in combination with the power supply with 240 V into the power supply what is your measured current into the power supply? Should use an RMS ammeter, but at a PF of 0.9 an average reading meter may be adequate. A Fluke 27 is average reading, and an 87 is RMS.

.

Same for both L1 and L2, 0.554A
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RumRunner

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The one thing that you can be relatively sure of is that the input components (diodes, switching transistors, or whatever) will be carrying twice the current to get the same power on the output side going to the LEDs. Only the manufacturer knows whether they can handle that double current or not. Long term thermal damage to semiconductors is quite possible even though they may appear initially to work fine.

OP did feed the switching transformer with 240 volts which is lower than nameplate rating of 347 volt minimum.
By OHM's Law, we could infer that current will go up because of low input voltage. . . theoretically correct.

Most newer design switching power supplies have both constant voltage (CV) and constant current
output capability. Depending on the condition of the input voltage, the TTL (transistor Logic) could be deployed in the circuit to utilize either CV or CC in order to work in a closed loop control of the switching transistor.
The output is constantly monitored for any changes outside the design premise. If for instance there is an anomaly that will cause instability of the output, either CV or CC will selectively (automatically) switch to proper mode in order to correct the problem.

The low voltage (240 Volts) instead of 347 v that OP is trying (or had already tried) evidently worked.

The reason that it works is; the switching transistor enables the charging capacitor to charge and discharge due to the opening and closing of the switch. Charging when open, discharging when closed.
This charging/discharging routine is what raises the voltage to almost in parity with the needs of the electronic components.
Since most switching power supplies are designed for universal use, the wide range certainly make economic sense.

Some countries operate at 250 volts. The 347 v volt name plate rating is measured at the emitter and base junction of the power transistor. So, when fed from a 240 volt source the peak reading would be 339.0 volts.

The 347 v volt nameplate is the theoretical PP (250 volt X Sq rt of 2) which is roughly 353 v peak.

Bottom line is, it will work but at a reduced luminescent. You have to go through the power supply and NOT hook the LEDs directly to a 240v wall plug. This way you still get the advantage of a modulated power source.

One way to check if it operates in CV mode is; if at this low input voltage the LEDs flicker.. . .usually when in constant current mode flickering is unnoticeable because of the rapid response in controlling the output.
 

gar

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Location
Ann Arbor, Michigan
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EE
180226-2020 EST

karn:

In my post #11 there is a mistake.

0.6*347/240 = 1.44 A
should be 0.87 and not 1.44 . The 0.6 got lost somehow in my original calculation, possibly I never entered it. 0.87 A is still a higher current than the power supply input rating.

I believe your power supply is a two wire input. Thus, both your L1 and L2 currents should be the same.

You are only reading 0.55 A at 240 V input. That is a VA input of 132. Actual power input will be less and might be about 100 W.

Your 0.55 A input is below the power supply input rating and you may be OK, but we know virtually nothing about the power supply, and a substantial input under voltage might cause some other kind of problem rather than just heat related.

I would really like to see output measurements as well as input, and from 240 to 480 V input.

Is there any sort of voltage, current, or power marking on the actual LED bulb. You can easily determine if the bulb itself is be driven with AC or DC with your meter.

.
 

gar

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EE
180228-1640 EST

FionaZuppa:

The reference you provided is very useful. However, GE provided no information on what the product is or how it works. One has to work backwards from little tidbits of information.


The output is DC seen by a very small + and - in a drawing.

The output is a constant currrent within some DC voltage limit range. Meaning that within the specified voltage range the currrent is approximately constant. The value of the constant current is programmable by some unknown means.

The input is an AC sine wave within the specified range, and input current is expected to be within the range indicated when fully loaded.

.
 

FionaZuppa

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AZ
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Part Time Electrician (semi retired, old) - EE retired.
gar,
almost all LED driver PS's are DC output. some wonky landscape lighting stuff uses AC PS and the lamps have small controller boards that change AC to DC as well as do the dimming/color functions, and the control is addressable signals on the AC output lines of the PS.

but, i also did note their address and #, your observations of weak/poor PDF should prompt the reader to call GE.
 
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