More electrical updating advice needed

[Otters]

Sometime back I asked for help in figuring out my crazy electrical system in my '77 13' Scamp the the PO had unfortuanately "Updated". Well we got that sorted out and now I want to correct the mess.
I recently added a 100W solar panel and 30w MPPT controller. Its working fabulously. but I still have the load for the trailer running from the battery to the lights, fan, etc. I don't have a converter or inverter and don't seem to need it. I specifically have 2 LED lights, 2 cigarette lighter type plugs, a Fantastic fan, stove vent with light, and 3way fridge (I probably won't be running the fridge on 12v). Although I have all of this stuff, my 12v ussage is quite low except for use of the fantastic fan.
I want to redo the wiring to have the load come off of the MPPT controller (Isn't that the way it should work?). Here's the info on the controller:
Product features:

Applicable to various types of batteries,
MPPT function
Temperature sensor battery charging compensation
Overload protection (automatic restoration)
Overcharge protection
Short circuit protection (automatic restoration) ,
Thunder protection
Reverse discharge protection
Reverse polarity connection protection (automatic restoration)
Under voltage protection

ConnectionAs shown in the following diagram of connection,the controller’s six terminals have the definite connection sign.



Function:

1. Always keep the battery on full voltage condition.
2. Prevent the battery from over-charging.
3. Prevent the battery from over-discharging.
4. Prevent the battery from reverse charging to solar panels during nights.
5. Reverse Polarity Protection for Battery
6. Reverse Polarity Protection for Solar panels
7. When the current of the load exceeds the rated current of the controller, the controller will activate the protection mode and lock up.
8. When the load short circuited, the controller will activate the protection mode and lock up.
9. When the battery voltage is low, the controller will automatically cut off the load from the system.If the voltage of battery is back to normal and the load will restart working.
10. Thunder protection
11. According to the battery voltage grade,the controller can automatically set charge-off voltage, the load-off voltage, the load-restore voltage.(The parameter is default under 25? condition, locked by the CPU procedure,cannot adjust.)
12. The controller will automatically compensate the temperature of the charging voltage according to the changes of ambient temperature

I am thinking about using this fuse box from Vintage Trailers. They recommend using a 12v 55 amp circuit breaker between the battery and fuse box and 8 gauge wire.

My questions:
1. Is this the right way to wire the 12volt system?
2. Is there something better to use than VTs fuse box?
3. Do I still need the 55 amp circuit breaker with the MPPT controller and should it go between the controller and the fuse box?
4. Do I really need 8 gauge wire or is 10 sufficient?
5. I don't want overkill, but want it to be safe; is it?
6 Anything else necessary here that I'm missing.

12V RV Fuse Box
12V Circuit Breaker 50A

Thanks in advance for any advice you can provide me.

Linda

[Ed Harris]

You merely connect the charge control to the battery just like any other charger and you will have it exactly as it should be.

The loads are run from the battery and the solar control is just another charger for the battery,nothing more.

All the rest is just lipstick maybe as far as the basics are concerned so I will just stop here for now to make that point!

[cpaharley2008]

X2 what Ed says,.... keep it simple

[pugslyyy]

What is the specific MPPT controller you are using?

Your first image and second image show two very different system configurations. Which are you planning on doing?

[steve dunham]

You haven't made the system "Safer " just more complicated and prone to failure

[Bob Miller]

FWIW: (And my usual and customary pitch anyway) If you haven't already bought parts, rather than patching together a bunch of components for the DC side, as well as still using some possibly 35+ y.o. parts on the AC side, think about using a Progressive Dynamics PD-4045 power chassis instead. It will give you all new AC & DC Dist, lots of fuses, a smart charger and more than enought power capacity. And you can still connect the Solar stuff easily. I have now installed more than 1/2 dozen of these and recommend them without reservation.

[David B.]

Linda, I agree with Ed. Our 13' Scamp uses a 100 watt solar panel, LED lighting, a fantastic fan, and a 12 volt only Danfoss style refrigerator. I removed the converter when it quit working, and added a smart charger for piece of mind prior to going on a 60 day 9 thousand mile vacation. I didn't know how well the solar would work, and how many rainy days we would encounter. We never had to plug in once, but only had two rainy days the entire time. I have since added a Black and Decker 75 watt power inverter to charge our lap top, phones, and run a few electrical items briefly if needed.

[Eddie Longest]

I usually use the Blue Seas 5025 panel for older the S-13's to clean up the 12VDC house wiring. And a 7pin junction box to clean up the running light mess. But Bob also suggests a good option.
blue seas fuse block | eBay
http://www.etrailer.com/Accessories-...tro/38656.html

[Roy in TO]

Originally Posted by Ed Harris

The loads are run from the battery and the solar control is just another charger for the battery,nothing more.

All the rest is just lipstick maybe as far as the basics are concerned so I will just stop here for now to make that point!

I don't consider functions 4, 7 & 9 to be lipstick.

Originally Posted by Otters

Function:

1. Always keep the battery on full voltage condition.
2. Prevent the battery from over-charging.
3. Prevent the battery from over-discharging.
4. Prevent the battery from reverse charging to solar panels during nights.
5. Reverse Polarity Protection for Battery
6. Reverse Polarity Protection for Solar panels
7. When the current of the load exceeds the rated current of the controller, the controller will activate the protection mode and lock up.
8. When the load short circuited, the controller will activate the protection mode and lock up.
9. When the battery voltage is low, the controller will automatically cut off the load from the system.If the voltage of battery is back to normal and the load will restart working.
10. Thunder protection
11. According to the battery voltage grade,the controller can automatically set charge-off voltage, the load-off voltage, the load-restore voltage.(The parameter is default under 25? condition, locked by the CPU procedure,cannot adjust.)
12. The controller will automatically compensate the temperature of the charging voltage according to the changes of ambient temperature

[Carol H]

Originally Posted by Ed Harris

You merely connect the charge control to the battery just like any other charger and you will have it exactly as it should be.

The loads are run from the battery and the solar control is just another charger for the battery,nothing more.

. The solar panel controller is just that! It's there to control the input of power from the solar panel. It's designed to stop the panel from over charging the battery not to control your battery output. Although some controllers will protect against power drain.

Keep it simple & you will be a much happier camper in the long run

[Otters]

Originally Posted by pugslyyy

What is the specific MPPT controller you are using?

Your first image and second image show two very different system configurations. Which are you planning on doing?

I have the MPPT controller in the first image. The second is the image from Vintage trailer showing an example schematic for the Fuse Box they sell.

Thanks everyone for the comments. I need to digest it all and will probably have more questions later.

I do wonder though why an MPPT controller like the one I have, has the "Load" connectors, if they're not at all necessary.

This is all new to me and I want it to be safe as well as maximum usefullness so I appreciate your help.

[Roy in TO]

Originally Posted by Otters

I do wonder though why an MPPT controller like the one I have, has the "Load" connectors, if they're not at all necessary.

The controllers are used in more places than just campers. The load connectors are there to protect expensive battery banks from being overdrawn to the point of damaging them.

[Otters]

Originally Posted by Roy in TO

The controllers are used in more places than just campers. The load connectors are there to protect expensive battery banks from being overdrawn to the point of damaging them.

I see what you're saying Roy. Makes sense and I sure don't want to create work for myself if there's no benefit--more time for camping and having fun.

Bob and Eddie: Thanks for these recommendations on the fuse boxes. I'll likely buy one or the other and that should clean up my wiring concerns.

Linda

[hotfishtacos]

Originally Posted by Otters

I do wonder though why an MPPT controller like the one I have, has the "Load" connectors, if they're not at all necessary.

Linda, I have made a lot of electrical modifications to my 19' Escape including a high-end solar controller that also has load controller function like yours but I don't use it. These controllers are designed to either control the solar charging of the batteries or act as a load controller from the batteries to the load, but not both. I suggest that you use the solar and battery terminals on your controller connected appropriately so it functions as a solar controller only and then connect the trailer panel to your batteries through an appropriately sized breaker. Don't use the load feature of the controller...I was also confused with this when I got my controller and had to wire it in. I noticed in the second schematic it recommends 8 AWG CU conductor. For your size trailer with the wiring runs and loads you have you shouldn't need any more than 10 AWG...and I think you should have a 30 amp (not 50 amp) self-resetting breakers between the output of the solar panels and the controller and the output line from the controller to the batteries and from the batteries to the trailer distribution panel... and as everyone else said, "Keep it simple!" Good luck!

Steve

[steve dunham]

Self resetting over current devices often cause as many problems as they solve . If a piece of equipment faults the breaker keeps trying to reset often until it destroy itself or the piece of equipment. Automatic resetting circuit breakers are especially dangerous when used with rotating or moving equipment . Circuit breakers are electric/mechanical devices and often corrode internally changing the trip point and are supposed to be exercised on a regular basis Fuses may be low tech but they consistently work. I agree with Mr. Miller start with a good converter and eliminate a lot of problems

[Bob Miller]

Add to Steves comments that regular switch type AC circuit breakers also change value as they age, especially if they are used as on/off switches on a regular basis. New breakers for most panels are in the under $10 range and new ones are always a good idea on older panels.

[Otters]

Thanks for the additional info. I checked out installation for Bob's PD 4045 on the net last night. Yikes...I hope and can do that--seems complicated. So forewarning Bob. You may be tapped for LOTS of questions.

[Roy in TO]

Originally Posted by hotfishtacos

These controllers are designed to either control the solar charging of the batteries or act as a load controller from the batteries to the load, but not both.

Perhaps the simple controllers, mine was designed for both. It also has a USB connection to download data to a computer. I can keep track of charging and loads for up to a year.

[hotfishtacos]

Originally Posted by steve dunham

Self resetting over current devices often cause as many problems as they solve . If a piece of equipment faults the breaker keeps trying to reset often until it destroy itself or the piece of equipment. Automatic resetting circuit breakers are especially dangerous when used with rotating or moving equipment . Circuit breakers are electric/mechanical devices and often corrode internally changing the trip point and are supposed to be exercised on a regular basis Fuses may be low tech but they consistently work. I agree with Mr. Miller start with a good converter and eliminate a lot of problems

Steve, it's standard practice to use self-resetting circuit breakers in RVs on the circuits we have been discussing. These are specifically designed for vehicles with DC applications. My Escape 19' has several of them wired in from the factory. I will bet your Casita has one between the battery and the distribution panel. If you think it is dangerous and will corrode over time maybe you should remove it.