Equipt FAQ: National Luna Fridge/Freezer Controls

Video Transcript

Hi, this is Paul with Equipt. I wanted to take a minute or two to talk to you about how to use the controls on a National Lunar fridge. They're a little bit unique, and looking at them straight off, there might be some confusion as to what's going on here, but it's pretty straightforward. I just want to touch base on it.

What we're looking at here is our most popular unit, which is the legacy dual control 50-liter fridge. It has a 40-liter zone and a 10-liter zone in it, so we have two controls that are independently controlled.

How to Make the Fridge Work

First of all, you hold the up arrow in for two seconds, and it comes on. Initially, you'll see a pile of eights across all of the control there. It'll flash a couple of things at you as it's doing its internal diagnostic. The fridge is set up so that when it first receives power, it goes through an internal diagnostic to make sure everything is okay. It might not click on immediately; sometimes that takes just a few seconds to get going.

When you give it a couple of seconds, you'll end up coming up with a temperature rating on the fridge. Now, you have on two of the displays what the temperature is in Celsius in each one of those. My personal preference is I like to have my fridge section, which is the left section, at about two degrees Celsius, which is about 36 degrees Fahrenheit. So, I hold the down arrow for three seconds, and it starts to flash at me.

This says right now that it's set at -10, which is pretty darn cool, so I'm going to hit the up arrow until I get to two degrees Celsius. It's going to flash for a couple more seconds, and once that stops flashing, that section is now set at two degrees Celsius. It says it's at 15 right now, and it's going to cool down to 2 degrees Celsius.

Freezer Side

For my freezer side, I'm going to do the same thing. I'm going to hold down that lower button for temperature setting. It says right now that it's at one degree Celsius. I think that's a little bit high for my freezer section. I typically like to have my freezer section at about 10 degrees Celsius, which is pretty darn low and is a good temperature for holding ice cream and ice and things that you put in there frozen. At that temperature, you can go lower, that's for darn sure. Do you need to? I think is what I would say to you. The lower you go, the more your fridge is going to run to get to a temperature that might not be necessary to keep something frozen. I found that minus 10 is plenty fine for that.

Battery Protection

Other things that you see on this control here is up in the top left corner of any of the fridges on the line. You have here what they call battery protection, and I call these pain thresholds. What it is, is the level of battery voltage available to it that the fridge will automatically turn itself off at. They have it set here at high is 11.5, medium is 10.5, and low is 9.5, and they've even put low in red, and there's a good reason there.

In our battery systems, you can hook this fridge up to your main battery, an auxiliary battery, a lithium battery, or whatever your choices might be. As the battery consumption goes on, the voltage in those batteries slowly lowers over time. The 11.5 setting is a rather high setting and is typically used for when you have this fridge hooked up to the main battery in your vehicle, and you want to maintain enough current in that battery to start your vehicle and get home. Rule number one: get home, right? So, you've got to be able to start your vehicle. If you put in 11.5, chances are you're going to have enough power in that battery to start your vehicle and get home.

Compressor Energy Usage

One thing I want to talk about when we're talking about this is how the compressor uses energy in the National Lunar fridge unit. When a fridge starts up, there is a bump of power needed higher than normal. It's called a bump start, and so the draw of energy goes up rather high. It's a high startup to get the compressor rolling, and then it lowers down and runs on a more common basis.

How National Luna has set up their variable voltage compressor is that if the voltage is down below 13 volts available, it will modulate itself to run at roughly two and a half amps of current over time. If the voltage available to it is above 13, it will run at four amps, run as fast as it can to cool down.

With that in mind, what we need to think about here when we're talking about voltage and where these pain thresholds are is the bump start. When you have a high consumption spike to start that compressor, if your voltage is down a little bit and the spike to start that fridge goes up, the demand is above what your battery will hold, the fridge won't run. So, it might be that your battery is sitting at 11.6, okay, that's just fine. The fridge will try to start and will require a higher bump to start, and it won't stop. It'll just start to flash lights at you, triple H, saying that there's not enough battery to start that, which it's doing its job because it doesn't want to use energy more than what you want it to use.