# Minimum load on MLV transformer



## Ryanlacey (Mar 27, 2013)

Hi guys, 

I had a really interesting conversation with the tech support at Elco lighting the other day that I'm just dying to get some comments on. 

Setup involves ~15 year old Elco 4" IC low voltage recessed housings. On board 50 VA magnetic transformers designed to push MR16 Halogen. Very common setup in some parts of the country. Objective is to convert to Soraa MR16 LED lamps. No dimmer involved. 

Super easy right? Nope. 

For some reason I reached out to Elco tech support just to double check to see if they had any guidance on LED lamping, specific to the old trims I'm working with. I guess I was just feeling OCD that day. 

My mind was blown when the tech support guy said that my plan to install 7 or 8 watt Soraa Lamps powered by their MAGNETIC transformer was not good. He insisted that these transformers really needed to be loaded to something like 30 or 40 percent at the minumum (don't quote me on that number) and that they would overheat if under loaded. He went on to say they were designed for halogens, etc etc. I was just like "....HUH?!" I ended up calling back an hour later and debating him... he sort of started to lose his patience with me but held steadfast to his explanation. 

His suggestion was to remove the existing transformers and replace with ELV such as light tech LET-60. I know this driver / lamp combination to work well and I'm fine doing it, but it's really a waste of time and money in my opinion to change out a whole bunch of mag transformers. 

This is the most peculiar thing I've heard in a long time. I'm so accustomed to watching out for minimum loads when using solid state drivers, switches and dimmers. But I've NEVER heard of a minimum load requirement with a magnetic transformer and I don't agree with it one bit. Especially overheating by under loading. Sounds like complete nonsense to me, so I'm very eager to hear what people think on this. 

No disrespect intended towards Elco or their tech support department. I really appreciate their accessibility. 

RL


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## SWDweller (Dec 9, 2020)

I wish I could help. This is news to me, seems wrong but the only way to find out would be take a transformer and light load it and see if the temp climbed..


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## splatz (May 23, 2015)

I am not at all certain, but I am definitely thinking you're right to be doubtful, and he's wrong about magnetic transformers.



http://www.semperfipowersupply.com/kb/uploads/doc/cases/mag_diff_elec.pdf


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## gpop (May 14, 2018)

Transformer losses will be converted into heat. If you look at it based on cost to run then your transformer looses may be higher than your load. Add the extra cost to dissipate the heat and your led cost savings dropped from 32 watt per light to maybe less then 20. The higher the load the less the transformer looses count as a percentage towards the total load.


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## Almost Retired (Sep 14, 2021)

Ryanlacey said:


> Hi guys,
> 
> I had a really interesting conversation with the tech support at Elco lighting the other day that I'm just dying to get some comments on.
> 
> ...


Its been 4 months. Do you have an update? any kind of results ?


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