Minimum load required for 2424LV controller.

[Jim Burrow]

Found out something about a little solar system. I have the MTTP 2424LV-msd (all-in-one) controller/inverter. Up until this time I have been using a 140-watt fan or 100-watt heat lamp as my load from my 2424lv. For several months the 2424lv has been sitting on my workbench in my hanger and working flawlessly. But yesterday I brought the system home so I could connect solar panels to the system as I don't have access to the direct sun at my hanger.

With respect to my house, all lights are LED so while checking my system before connecting the array panel. (System not connected to the house yet) I used one 20-watt led bulb and on battery power, but all the bulb would do is flicker on and off. I added 3 more 9-watt led bulbs and all the light would still do is flicker and not come on. So I figured the controller isn't putting out a high enough initial voltage to trigger the LED bulbs. So I removed the LED bulbs and connected a 40-watt incandescent bulb and got the same results.

It wasn't until I increased to Load with a 100-watt incandescent light bulb that the light would come on without any flickering. I then tried a 60-watt bulb with different size LED bulbs. Every time the lights would flicker and not come on until I reached 80 watts.

I'm now using a 60-watt bulb with a 20-watt LED bulb and the lights don't flicker and they come on instantly.

So it looks like my 2424lv needs an ac load of a minimum of 80-watts. So when I get around to finally connecting my system to the house, I will have to make sure I always have at least 80-watts of power on in the house or my controller could cause hell with the TV's and my computer and other electronics.

However, this shouldn't be a problem as the lowest power drawn in my house is 154-watts of electronics and refrigerator after I and the wife go to bed.

 

[snoobler]

Did you disable the power saving feature from the prior incident?

 

[Jim Burrow]

I didn't try disabling the power saving because that last time I had low battery voltage, the power savings kicked in and it wouldn't let me run a load of any wattage.

however, for the fun of it, I will disable it and see if I can run a load with less than 80 watts. I would assume the power saving mode is a safety feature to protect your system. But since the system is not connected to the house yet, but in my back yard shed and fired up, I can play around with it.

I also connected one solar panel out of 6 today and will start playing with it too. In a few days, I will connect a second one on my shed and will be in series for a total of 80 Volts OSC. I was surprised to see my one panel pumping out 39-volts and 34-watts on a very overcast day (about to rain)

 

[snoobler]

Power saving mode is to save power in the event of low/no-loads. It's basically something you never want on if it's powering a house.

 

[Jim Burrow]

Power saving mode is to save power in the event of low/no-loads. It's basically something you never want on if it's powering a house.

Ok, thank you, I have always had it disabled. I just have to make sure that I always have a load greater than 80 watts. which will be no issue once I install it on the house. But before I cut the utility lines to install the controller/inverter, I will run electrical cords through the house as I do during the summer months when we lose power and I light up the house with a gas generator.

 

[snoobler]

If it's behaving like that with power-save disabled, I would be concerned the unit is malfunctioning unless there is some other setting that might influence the behavior.

 

[Jim Burrow]

If it's behaving like that with power-save disabled, I would be concerned the unit is malfunctioning unless there is some other setting that might influence the behavior.

I would hate to think the controller/inverter is malfunctioning as it is not one of those copycat MMPT 2424LV controllers but from MMPT the company.

 

[snoobler]

I know it's comparing apples to oranges, but I routinely operate my Victron 5kW at less than 50W, and I never have an issue. I would scour the manual for anything that might influence that behavior. Otherwise, I'd be concerned about the longevity of the unit.

There are a number of descriptions on this site where "genuine" MPP Solar units are DOA or malfunction. They're also dirt cheap - common for Chinese products to use the consumer as their Quality Control department.

 

[Jim Burrow]

I know it's comparing apples to oranges, but I routinely operate my Victron 5kW at less than 50W, and I never have an issue. I would scour the manual for anything that might influence that behavior. Otherwise, I'd be concerned about the longevity of the unit.

There are a number of descriptions on this site where "genuine" MPP Solar units are DOA or malfunction. They're also dirt cheap - common for Chinese products to use the consumer as their Quality Control department.

That's what scares me, I might have bought one of those copycat MPPT controllers and believing that I bought one of the good ones from the company. But since the house won't be running on less than 150-watts after I've gone to bed and turned off most stuff, I think I will be Ok. I will try it someday when the wife is not home and I run power cords through the house to test my theory.

 

[DougCardo]

Jim,

I dont' know if this is relevant or not, but I have seen this behavior before with some LED bulbs when used on line power. Some leds dont like to be the only load on a circuit. Has something to do with the fact they are diodes, and some bulbs require a small load on the circuit. I believe Lutron makes a resistor that can be wired into the switch to provide a small load. Or some people will use one standard bulb to provide more load, or use several LED bulbs to ensure the load is sufficient.

 

[Jim Burrow]

Jim,

I dont' know if this is relevant or not, but I have seen this behavior before with some LED bulbs when used on line power. Some leds dont like to be the only load on a circuit. Has something to do with the fact they are diodes, and some bulbs require a small load on the circuit. I believe Lutron makes a resistor that can be wired into the switch to provide a small load. Or some people will use one standard bulb to provide more load, or use several LED bulbs to ensure the load is sufficient.

your right. The same seems to be true for my refrigerator and electric heater (just using the heater for a heavy load test of 900 watts, but needed the light bulb for it to kick on). So I'm using an inconsistent 60-watt bulb. Hat to waste the energy, but everything in my house is fluorescent or LED or very low consumption like the TVs.

 

[DougCardo]

Cool. seems like you have it figured out. If your interested in the Lutron resistor, they are about $5. Just search google for "LUTRON-LUT-MLC".

From my experience, I tend to think the bigger brand LEDs like Halo & Lithonia provide the best power filtering and have the best results with switches/dimmers.

 

[Jim Burrow]

Cool. seems like you have it figured out. If your interested in the Lutron resistor, they are about $5. Just search google for "LUTRON-LUT-MLC". View attachment 35893

From my experience, I tend to think the bigger brand LEDs like Halo & Lithonia provide the best power filtering and have the best results with switches/dimmers.

thanks, Doug, I think the resistor idea is better than having a light on all night and you don't have to keep changing the bulb when it burns out.

Without doing any math, what size resistor are you using in ohms and I assume you choose a voltage rating of at least 120v

 

[DougCardo]

I'm not really sure since I have actually never used one before. when i google searched for "led dimmer resistor" I see one being sold that is 10K ohms (which will pull about 1 watt). And it appears that the Lutron may actually be a "0.47uF X1 310VAC rated capacitor" according to amazon reviews. Although it may not fix your problem, I think the Lutron is the safest way to go. Its a fine balance of pulling out enough watts, but the device adequately cooling itself (of which the Lutron should do). I also found some discussion on this here:

will a dummy load cure all ills for LED dimming? - Page 1

will a dummy load cure all ills for LED dimming? - Page 1

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