Solar "Load" connection?

[BobD]

I'm using a Morningstar Controller MPPT-15L an a FWC Eagle. Where do I make the "load" connection? I initially attached directly to the Blue Sea fuse panel but that immediately powers everything while the panel is in direct sunlight regardless of the FWC Main 12VDC On/Off switch. I'm assuming that I should be on the +12VDC side of the FWC Main 12VDC On/Off switch? I tried a search but ended up chasing my tail...

 

[DrJ]

You could check with your instruction manual, but most solar controllers do much better if they are connected directly to the battery with both the load(+) and negative side.
If the power is being sent through other wiring, it creates a voltage drop which means less power to the battery. It also may change how much power is being sent from the panels and the controller may not read the correct voltage at the battery.

I'd just connect it directly to the battery.

 

[Casa Escarlata Robles Too]

Bob I am no expert ,but I have just been working on my solar system.
I installed a watt meter to my solar controller and it calls for a "source" side and a"load" side.
The load in this case is the battery the source side is the solar panel side of the controller.
Hope this helps you.
I am sure you will get other input on this.
Frank

 

[MarkBC]

You could check with your instruction manual, but most solar controllers do much better if they are connected directly to the battery with both the load(+) and negative side.
If the power is being sent through other wiring, it creates a voltage drop which means less power to the battery. It also may change how much power is being sent from the panels and the controller may not read the correct voltage at the battery.

I'd just connect it directly to the battery.

Bob I am no expert ,but I have just been working on my solar system.
I installed a watt meter to my solar controller and it calls for a "source" side and a"load" side.
The load in this case is the battery the source side is the solar panel side of the controller.
Hope this helps you.
I am sure you will get other input on this.
Frank

Guys, I think the "load" he's referring to really does mean "load" -- that is, the stuff that uses power. A lot of solar charge controllers have a "load control" function. The power-using circuit connects to the Load output on the controller, and the controller can be set to shut off power if the battery gets too low.

The load-control outputs are separate from the connection between the controller and the battery.

 

[BobD]

Thanks guys, a great help as always. The manual is vague as hell and just references a load (light bulb schematic symbol). The way I had run the load wiring was down to the Blue Sea distribution panel (FWC factory wiring). I ended up connecting my + load line to the "hot" side of the FWC 12VDC switch, and the - load line to the local ground buss. Once I reinstalled the fuses and it went through the self test it's working like a champ. So now the MPPT controller will sense the entire load once I turn on power to the camper, which is what I wanted. In retrospect wiring the load directly to the batteries would have accomplished the same thing. Hopefully this will make it a little easier for the next guy.

Thanks again for all the insight and help that this forum offers, what a resource!

 

[mynxd]

Bob, I have the same controller. The +/- "load" terminals should be connected to your On/Off Switch (your On/Off switch should no longer be connected to the battery). If connected in this manner, The "load" terminal on the controller will act as a low voltage disconnect switch. If Dip switch 2 on the controller is in the "off" position, , the controller will stop power going to the On/Off switch when the controller detects battery voltage is less then 11.5V. In the "on" position the controller disconnects power at 11.0V. Dip switch 3 should be off if you have an AGM battery / on for Lead Acid battery.

Grant

 

[DrJ]

Some solar controllers do have a total of 3 inputs or outputs.
One input is the incoming power from the panel.
One output is outgoing to the battery.
One output can be to run items you just want to run off solar - not battery power.

I'm not sure if that is the same as yours or not.

I've never really hooked up anything to the third option to run power only off solar.

 

[MarkBC]

My load output (Blue Sky SOLAR BOOST™ 2512i(X)-HV) is pulling from the battery. That's why it has the low-voltage disconnect to protect the battery.

 

[DrJ]

My load output (Blue Sky SOLAR BOOST™ 2512i(X)-HV) is not based on solar only, it's pulling from the battery. That's why it has the low-voltage disconnect to protect the battery.

I think you are correct on that. Some controllers can direct solar power to the battery and the "load". If the solar cannot keep up with the load they can be programed to draw battery power to keep up.

Isn't most of the power run through the load portion only for smaller volts or amps?

I've actually never figured out what would be helpful to set up that way.

Do you have an example on how it would use with a camper?

I've always had everything run directly through the battery and the solar to power the battery directly.

 

[MarkBC]

...Isn't most of the power run through the load portion only for smaller volts or amps?

...Do you have an example on how it would use with a camper?

I've always had everything run directly through the battery and the solar to power the battery directly.

I don't really know. I don't use the auxiliary/load output either, and I haven't even given much thought to "should I and why?"

But the datasheet for my solar charge controller (BSE 2512iX-HV) says:
"...The auxiliary output can serve as a 25 amp load controller..."
So if that means what it seems to mean, 25 amps is a lot.

But again, I've never used the auxiliary/load output. I have the OEM power line (the one which feeds power to lights and furnace fan, etc. and through which the truck alternator can charge the battery) connected directly to the battery AND I have a separate dedicated line to the DC compressor fridge connected directly to the battery. (the fridge installation manual suggested/required using a direct connection to the battery...for some reason).

 

[Casa Escarlata Robles Too]

This is all some good but complicated info.
On my solar controller,which is 120w/10a,a simple one.
I have the the load output connected through the new watt meter than to the battery.
My controller also has the third outlet to power directly from the solar,but don't use it.
I have been watching the camper panel output % and compare it to the output% of my house system.
Today a nice sunny day both systems were about 60/70% this morning with clear sky's.
I feel this is a good % as the camper panels are flat and the ones on the house are angled more to the sun.
I have been getting as much as 85% with the camper system.
More than enough for my needs.

Thanks for all the info,even if I don't understand all of it.
Frank

 

[camelracer]

I'm also using this Morningstar controller. The load terminals need to be connected to the camper power switch and the battery terminals connected to the battery. This will provide low voltage protection for the battery, limit the maximum load current and monitor the system. If you have the monitor panel for this controller you can log your solar voltage, power going to the battery and power going to the load for 30 days. Not using the load terminals and connecting the load directly to the battery will disable these functions.

 

[BobD]

Bob, I have the same controller. The +/- "load" terminals should be connected to your On/Off Switch (your On/Off switch should no longer be connected to the battery). If connected in this manner, The "load" terminal on the controller will act as a low voltage disconnect switch. If Dip switch 2 on the controller is in the "off" position, , the controller will stop power going to the On/Off switch when the controller detects battery voltage is less then 11.5V. In the "on" position the controller disconnects power at 11.0V. Dip switch 3 should be off if you have an AGM battery / on for Lead Acid battery.

Grant

I'm also using this Morningstar controller. The load terminals need to be connected to the camper power switch and the battery terminals connected to the battery. This will provide low voltage protection for the battery, limit the maximum load current and monitor the system. If you have the monitor panel for this controller you can log your solar voltage, power going to the battery and power going to the load for 30 days. Not using the load terminals and connecting the load directly to the battery will disable these functions.

This makes sense, thanks. Right now the controller + Load line is connected to the main power switch along with the +12VDC from the batteries. I'll go ahead and disconnect the +12VDC line to the switch and cap it off.