MPP Solar 3048LV-MK AC Input

[Bud Martin]

Thanks! I always wonder about the Alibaba auto quote shipping price as how they figure out what it should be without knowing which states in the US the unit being shipped to, only 10 days, wow.

 

[Hedges]

When I do my final installation, the transfer switch will be between my service panel and the inverter.

It would be cleaner for me to run all of the wires going from the service panel to the inverter (AC in and out) through the same conduit for the transfer switch. Is there a problem with doing it that way?

All through one conduit is fine.
I have 2" diameter nipples between several boxes, fits many wires but some are getting crowded.
Also I put in "T" fittings so branches can be added later.
If conduit is over 2' long, ampacity of wires is to be derated according to how many current-carrying conductors in excess of three.
Under 2', no derating required.

 

[ArthurEld]

It is hard to understand how the wires effect each other.

And the transfer switch has a lot of wires. I will look into the derating current carrying conductors in conduit.

I saw somewhere that I can use a gutter instead of conduit and then I could have 30 current carrying conductors before derating.
That looks clean but probably not necessary for my setup.

Thanks Hedges.

 

[Hedges]

It is hard to understand how the wires effect each other.

And the transfer switch has a lot of wires. I will look into the derating current carrying conductors in conduit.

I saw somewhere that I can use a gutter instead of conduit and then I could have 30 current carrying conductors before derating.
That looks clean but probably not necessary for my setup.

Thanks Hedges.

Thermally.
Each wire dissipates power and produces heat = I^2 x R
Thermal insulators resist heat flow like electrical insulators resist current flow. They have a temperature drop across them like resistors have a voltage drop across them.
Multiple wires bundled together have thermal energy added together. That heat has to flow though outside of bundle and any conduit before dissipating in air.

Wire ampacity tables assume 30 degree C ambient (derate ampacity for higher ambient.) With 90 degree rated insulation, the ampacity table and derating for multiple conductors is based on what current would cause the wires to rise 60 degrees above ambient. The power dissipation in the wires which, when conducted as heat though insulation and conduit and transferred by convection to air reaches equilibrium with 60 degree rise.

For less than 2' distance bundled together, derating isn't required because heat flows lengthwise through the copper and escapes where the wires are spread apart.

 

[ArthurEld]

For less than 2' distance bundled together, derating isn't required because heat flows lengthwise through the copper and escapes where the wires are spread apart.

I was wondering why Reliance would supply 4' of wire if I had to keep them under 2' long.

Then I realized the 2' is for the length of the conduit not the length of wire.

 

[ArthurEld]

The Reliance transfer switch is meant for 240V. But this inverter is only 120V.
So, I just connected 1 hot wire and I am using 3 circuits.

Can I connect the one 120V hot wire from my inverter to both hots on the transfer switch so I can use all 6 circuits?

I tried connecting the 3 circuits on my own but I'm afraid to try using 6 circuits with 120V. ?

 

[Hedges]

Yes, 120V from inverter can go to both busbars in transfer switch.
Wire needs to be large enough for sum of all breakers it feeds, or inverter output, whichever is lower.

Whether using one busbar or both, make sure the existing house wiring you're feeding doesn't have two circuits sharing one neutral.
If one Romex 3 wire plus ground had white to neutral bar, red to main panel utility grid, black to transfer switch inverter running asynchronous from grid, then neutral could carry sum of red & black currents (or difference, depending on phase as it drifts). If red and black both to same 120V phase, white would carry sum all the time.

What would be OK is to put red and black on the same breaker. That way they only carry 20A combined and white neutral only carries 20A (rather than 20 + 20 = 40A.)

 

[ArthurEld]

Thanks a lot Hedges. I will be using less than 30A AC total.
I will check the neutrals.

 

[Thafella]

I am setting up a MPP Solar 3048LV-MK 48V all in one.
It has an AC charger that can output 60A.
Currently I plan to plug the AC input to a receptacle in my garage that has a 20A breaker.
Hedges warned me that this unit can use more current that 20A AC input.

I did a simple conversion -
60A X 48V = 2880W / 120V = 24A
or
60A X 60V = 3600W / 110V = 33A

I don't know which one is correct but I am sure I need more than 20A AC to get 60A DC

My electrical experience is weak.

Can someone please explain my AC input options to make 60A DC output?
I guess I might need to add a breaker to my main electrical panel.

My panel has a few 30A breakers for Dryer, Stove, Water Heater. The Dryer and Stove use special plugs and I don't know if they are 240V

I would prefer to do it in a way that doesn't require a permit. And this unit doesn't feed to grid.

I can make it work using the 20A input but I was hoping to charge my 280Ah battery at .2

What charging rates did you end up getting out of this?
I’ve been looking at the manual recently and it lists the charging rate as “60A @nominal input voltage” which I was hoping meant @120v

 

[ArthurEld]

What charging rates did you end up getting out of this?
I’ve been looking at the manual recently and it lists the charging rate as “60A @nominal input voltage” which I was hoping meant @120v

3048 is 48V and charges up to 60A using 120V AC input.
The solar charge controller can charge up to 80A but I haven't connected solar yet.

 

[ArthurEld]

I connected four 100W solar panels today. I'm still getting some shade but the display says about 200W is coming in.

Now I have experience.

 

[pjvon]

When I do my final installation, the transfer switch will be between my service panel and the inverter.

It would be cleaner for me to run all of the wires going from the service panel to the inverter (AC in and out) through the same conduit for the transfer switch. Is there a problem with doing it that way?

Did you run your inverter straight to your breaker box? Since the unit has a switch in it, was it necessary to use the service panel? I recently bought this unit and we have everything hooked up except the A/C output to the breaker box. We are not sure if we can do this. I am interested in knowing how you ended up finishing yours.
Thanks!

 

[ArthurEld]

Did you run your inverter straight to your breaker box? Since the unit has a switch in it, was it necessary to use the service panel? I recently bought this unit and we have everything hooked up except the A/C output to the breaker box. We are not sure if we can do this. I am interested in knowing how you ended up finishing yours.
Thanks!

I connected the A/C output to a transfer switch. If you connect it to the breaker box you would have to turn off all non critical loads.
I only put the critical loads through the transfer switch.

 

[pjvon]

Does your transfer switch automatically pull from the grid (like the inverter does) if you don't produce enough energy?

 

[ArthurEld]

Does your transfer switch automatically pull from the grid (like the inverter does) if you don't produce enough energy?

The switch is between grid and the inverter. I always left it switched to the inverter.
The inverter took power from the grid when it needed it.

 

[pjvon]

Great! Thank you!