kid models clarification

Started by harryn, September 19, 2018, 12:53:12 AM

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harryn

MidNite Solar Kid 30a MPPT MNKID-C1D2

vs

MidNite Solar Kid 30a MPPT MNKID-B - Black Charge Controller

I am attempting to gain some more clarity on the difference between these models - in a fairly detailed way.

Not just some buzz words, real technical differences in looks (front and back), mounting, significance, wiring, etc.

Also - do they all come with the extra lower plate now?  Seems like perhaps the dimensions specs need some adjustments?

Thanks

Harry

harryn

Also - can the kid be mounted against a flat surface - example a sheet of plywood, or is the assumption that it will vent heat into the space behind the wall?

Thanks

FNG

I have asked Robin for an exact explanation but they are the same KID at the start, I believe the C1D2 kid has a vented back and is assumed you will use the wall mount adapter to comply with C1D2 the standard kid though does not dissipate any heat through the back it is all dissipated from the fins on the front so mounting can be very versatile.

The front looks identical and as for the back, it basically does as well except for the vented back on the C1D2 model.

See the web pages for a detailed image:

http://www.midnitesolar.com/productPhoto.php?product_ID=669&productCatName=Charge%20Controllers%20-%20KID&productCat_ID=43&sortOrder=1&act=p

Where you see the screen on the C1D2 kid there is a solid aluminum cover on the standard kid

Doug

The C1 D2 model is Class  I Div II rated for hazardous (Explosive) areas.

harryn

#4
Thanks for the image of the back of the -C1D2 model.  I have seen some class 1 - div II wiring and sometimes they were N2 purged to prevent fumes from entering.  Perhaps that is the concept behind the screen on the back - to allow N2 to enter.

Is there a similar image of the back of the standard model?  I could not find it on the web site.

Due to space limitations, what I would like to do is use the standard -B version and mount it to a wood plate (back of the controller directly onto the board).  There isn't room for the extra wall mount bracket - just the controller.

I realize that wire access to that unit is difficult, so the bracket provides improved access.

If I purchase a standard -B model with the included plate, my understanding is that it comes with the wires fanned out to the connector in the bottom.  Can I just remove that extra bracket and terminate to the wires that are already coming out?

If that can work, then we can use it in our 24 volt product line and upgrade to a 30 amp controller vs the 20 amp controller that we are using now.

Since there is not any heat dissipation from the back, perhaps this can work?

I don't mind going to the -w version if that helps, but there isn't room for the side brackets.

It all goes into a ventilated but protective case.

FNG

yes the kid can be used without the brackets, I am a little confused about mounting it the way you describe? The way I would do it with no bracket is to cut a hole in the plywood using the included template and slide the kid into the hole in what we call a flush mount

harryn

We have really two applications:

1) Mounted on a base plate
- There is an 18mm plywood sheet that has various items mounted on it (charge controller, inverter, etc)
- It is a hard stop surface - nothing is mounted into or through it.
- Everything is screwed down to this more or less thermally insulating board.
- There is room in front of it, but side space is limited, so it really cannot be any larger than it is specified as being
- Heat transfer is all from the front side.
- There is not room for the extra surface mount bracket
- the entire setup is mounted in a water resistant box with ventilation as required for operation.

The downside of this situation is that one of the nice features of the kid is that it includes the battery SOC monitoring in the front panel, and it is more or less not accessible to the customer. (due to the enclosure)

In theory the kid could be "flush mounted", but it really is not "flush".  It is really more like "center of the unit's thickness" mounted from what I can tell.  The fins are of course necessary, but they stick out well beyond the surface of any wall that they would be mounted on, so their depth counts. 

According to the manual, it will stick out about 1.5 inches beyond the wall surface, which is not allowed in this application.  In this application, they would be damaged.  If you ever make another variation, please actually make it flush mount so that there is a definite mounting flange and nothing sticks out further, even if there are surface fins for heat transfer.

Page 11 indicates that there should be 2 inches of free air space behind the unit for heat transfer.  This spec is one of the reasons that we didn't choose the kid for this application earlier.  There is zero clearance when it is mounted on the base plate.  When I saw that no heat is removed via the back surface, this makes this application potentially possible.

Thanks for your insights.

harryn

Application 2)

- Mounted "through" a wall
- I guess this is sometimes referred to as "flush mount"
- The wall thickness is still typically 3/4 inch / 18mm, which substantially exceeds the 1/4 inch typical in the manual.
- It looks like the fins will stick out around 1.5 inches beyond the wall surface, so this can work in some applications - but not all of ours.

- The battery pack will be "behind" this wall, along with the wizbang jr.

I am still trying to figure out if the wires can be all routed directly out the back or if they have to go through the side ports?

Since the C1D2 model back is covered by a screen vs Al solid surface, was debating if one approach is easier than the other?  I assume that I can drill / add holes to the back for wire access?

Thanks

Harry

harryn

As I mentioned, we have a 20 amp solution now, but we try to purchase USA made products when possible and the 30 amp output capability would be nice to have.




harryn

#9
Just an FYI, I submitted a support ticket to help with the answer to this application.

Basically the installation manual suggests / indicates that there should be 2 inches of open space behind the kid no matter how it is installed, at least that is my interpretation of what is says.

I am needing to install it so that the back of the kid is hard mounted / screwed down to a plywood board.  In other words, no space behind it at all.

The application is 4 x 150 watt panels wired in series feeding a 24 volt lifeline agm battery pack, they can easily accept charge quickly.

There is not room around the sides for the extra mounting plate - just enough with a little extra for the kid.

I am trying to see if this will work properly or will over heat.  It will be mounted inside of a vehicle, so it will get warm in there.

If needed to make things work, I could potentially reduce the array to 3 x 150 watt, but 4 is preferred.

Thanks

HarryN

KyleM

QuotePage 11 indicates that there should be 2 inches of free air space behind the unit for heat transfer.  This spec is one of the reasons that we didn't choose the kid for this application earlier.  There is zero clearance when it is mounted on the base plate.  When I saw that no heat is removed via the back surface, this makes this application potentially possible.

The entire KID is one big heatsink, most of the heat is designed to go out the front, but not 100%.

We put the requirements in the manual for a reason. I am sure during our testing we must have run into a heat issue with the KID in an enclosed area or we would not have made the comment.

The inability to cool down a charge controller will seriously shorten the life of the product. It can also void the warranty.

There is no way to really know is to install one and find out. 

Kyle

mike90045

What about mounting the KID to a thick aluminum plate as a heat sink, instead of a sheet of plywood (thermal insulator) ?
http://tinyurl.com/LMR-Solar

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harryn

#12
Hi Mike,

The base plate of our system is an insulator - roughly similar to any other wall you might have in a home, garage, or shed.

As I mentioned, it is not possible to penetrate this "wall" as it is an integral part of our system.

In theory, an additional aluminum heat spreader could be designed so that the kid could mount onto it, but that would have to be larger than the kid's L x W dimensions.  The fins and heat spread calculations required would need to be engineered, and I don't have any data at all from MS on how to estimate this heat load.

As you can see from their answers, either they don't have it either, or don't want to share it - both make sense.

The big challenge that I am having with integrating in the product into ours is the mounting:

a) In a flush mount / surface mount approach
- Normally you would have a bezel with a wide enough flange for something like 1/4 -20 or at least many #4 bolts.
- Nothing would extend in front of the bezel flange thickness.
- In the case of the kid, the fins and some other items stick out well past the front flange, making them very difficult to protect
- Wiring it is difficult if the "wall" is very thick

b) Rear Mounting on a base plate
- This sort of defeats the purpose of having a built in user display, as back plate mounting means that the front cannot be accessed or seen without opening the cabinet
- Heat dissipation may or may not be an issue - hard to tell.

c) Altering Marine version
- In theory, maybe the marine version has a cleaner layout, but I cannot tell from the drawings and photos on the web site.
- A few photos of it from all angles would help
- Is it possible to post some photos from all sides of the marine version?  I am trying to determine if the fins still stick out as far in front as they do on the standard kid.

If one of these will work out for me I will buy one, but I am hesitant to drop $900 to purchase multiple versions just for lack of some photos and an engineering / marketing drawing.

Thanks

FNG

Harryn,
Email me, ryan@midnitesolar.com I believe I can get you some fancy PDFs and or drawings from engineering that will help

harryn

Thanks Ryan - email sent.  Really appreciate the help.

Harry