I should probably get the tech who programmed the system to come out and see what he can do with the system. So the programmable module in the panel should be able to adjust the driver in the luminaire. Please remember I’m an electrician and even though I have a masters license I get fog brain when I try to understand the stuff you guys work with. So to recap those two drivers I sent pictures of are not compatible with the 27E1000-D-73 chip.
Hi @evmyairi ,
The drivers supplying 700mA appear to be too much for the LEDs. It is possible the original tech installed 700mA drivers and was planning to use the dimming feature to reduce the current by half down to 350mA by setting the program to limit the dimming brightness to 50%. By having 5V on the dimming wire (via system program), it will cut the current by roughly half since it is a 0-10V input. The tech may want to reprogram and limit the brightness to about 50% (5V) if you plan to use the same 700mA drivers.
Otherwise it is possible to replace the drivers with correct (lower current) ones without a need to reprogram the system. Based on your schematic, it appears the system only provides on/off and dimming control signals to the drivers, so replacing the drivers appears would work. But again, we don’t know much about those systems and can’t really provide solid advice since it would not be something DigiKey currently carries or is able to support and give information on specifically.
It is also possible there was a miscommunication with the original tech as to how much current/voltage they thought the LEDs would be able to handle, so having a datasheet of the LED COB printed off for the tech will help put things in black in white for them to not overdrive the LEDs. There should be very minimal to no heat generation at the COB terminals. You should be able to hold your finger on the terminals without burning your finger.
Click here for the two 27E1000-D-73 COB options in our system (datasheets included). The test current listed (350mA) is typically the nominal operating constant current @ 25 degrees C, which should provide sufficient lighting with high reliability, with the ability to go up to the max current depending on duration, operating temperature, heat sinking/airflow, and other factors that will degrade lifespan anytime exceeding the test current. Max ratings are typically the max amount able to handle for very short durations, unlike in residential lighting where they can be left on for hours or even days.
Although the datasheet states “Reliable operation at up to 2X nominal drive current” (which would be the 700mA of your drivers), this is taken with a grain of salt as this may be a mixture of very short duration operation mixed with a touch of marketing salespitch. Anytime a datasheet does not give actual reliability test information running at these levels, it is safe to say the 700mA would not be recommended for typical applications. Datasheet also states, “Maximum rating provided for reference only.” This is also a red flag which states that it is for reference only and not the actual value to be used.
In summary
The LEDs will want to see 350mA of current at their recommended voltage rating during their normal operation. If the dimming circuitry is wired correctly, it will dim the LEDs (via analog 0-10V) by reducing the LED driver current from approximately 0-350mA. If you choose to operate the LEDs above 350mA by some margin to get brighter lighting, it will be at the expense of shorter lifespan, and monitoring the heat generation is crucial to view how much the heat sinking is able to successfully dissipate. Using an Infrared Gun or a Temperature Sensor Capable Multimeter can help with monitoring the heat generation.
Suggested Alternative Drivers
Click here for 350mA analog dimmable drivers, which match the LEDs and ‘should be’ plug-n-play.
Click here for higher 380mA - 500mA analog dimmable drivers, which would be overrating the LED nominal current, but depending how much brighter you need and how well the heat sinks are able to dissipate.
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The only problem with that is in the low-voltage panel. They replaced three of the 0 to 10 V modules with I believe reverse phase modules that’s why all of the 0 to 10 V control wiring is capped off in the low-voltage panel. I don’t know why they left one module in there that controls the sunroom recessed lights and they’re operating at 0-10v and they’re doing fine. None of those have burnt out. So I told the homeowner will call the tech who did the system and get a motor there and find out why they had those modules replaced and left one module in there that is 0-10v.
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Yep, I bet they were relying on the dimming system to reduce the current. Once they get the 0-10V controls on the remaining lights, all hopefully should go well.
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