MPP LV2424 - max AC input current

[dokmartin]

lol

when i made the decision to pass over the 'parallel operation' section of these manuals i remember thinking 'haha prob gonna miss something THERE'

and indeed, i see the recommendation. on the 3048 3kw claims a max line mode charge rate of 60A. It asks for 100A breaker on the battery here (mentioning a 83A max current on p.7) and 48A on the AC input. I checked the 5048 as well and found p much identical details for the ratings.

That sounds right, more or less, for protecting at max combined line mode load and max battery charge current. I guess what tripped me up was the call for 10AWG wire on that AC input line. I would rate 5.7kw @ 120VAC/50A at 4awg/6awg for any length to about 15 feet, as an input from gensets or EV charge station/ shore power connection.

 

[mrdavvv]

Jejej your not the only one, happened to me until i bought my second inverter for parallel instalation and discover that, and also someone else mentioned it in the last page.

10AWG?, maybe they want you to use silver conductors

 

[Mac6792]

Much of this conversation has been about requirements to support pass through. However, don't lose sight of the fact that the inverter also needs amperage to charge the batteries and could be doing complete pass through at a full 2400 watts as well as charging the battery at the same time at whatever amperage you configured it for

 

[dokmartin]

Much of this conversation has been about requirements to support pass through. However, don't lose sight of the fact that the inverter also needs amperage to charge the batteries and could be doing complete pass through at a full 2400 watts as well as charging the battery at the same time at whatever amperage you configured it for

That's exactly what we're talking about.

At least on the 3048 it seems the input AC breaker rating is specced for both passthrough full-load (to a load size that matches the inverter max, natch) AND the maximum line mode battery charge current (60A @ 60VDC). In this case 48A @ 120VAC input. That wire size recommendation is suspect tho imo

 

[madmax]

Well but can the inverter work as an AC passtrough and at the same time charge the batteries at 60A?, if the passtrough its 20A and the battery charging 15A, wouldnt the 40A fuse have some sense?.

After reading the docs again, it's the unit that can pass 40a. In other words, you can hook up to 40a worth of load direct to the unit. Only 20a will ever be provided by the unit. Any more, will set it to bypass mode. But that number has nothing to do with the charge rate.

 

[mrdavvv]

After reading the docs again, it's the unit that can pass 40a. In other words, you can hook up to 40a worth of load direct to the unit. Only 20a will ever be provided by the unit. Any more, will set it to bypass mode. But that number has nothing to do with the charge rate.

Where did you see that?

 

[madmax]

Where did you see that?

Page 24?

 

[heirloom hamlet]

Just FYI the manufacturer recomends 40A breaker for AC Input for a single one, and 80A for a parallel conection. Its a little hidden in page 33.

I'm not planning to do any AC input/charging... only solar. But what about AC output? Should my overkill 6awg wires leave the AC output connections on the LV2424 and go straight into a breaker box as a sort of cutoff? That's what I'm discerning, but what is the breaker size that should be used? It looks like these things are only capable of pushing 25a. Is that right? So what size output breaker should be used?

 

[mrdavvv]

Hello.
- Correct, inverter its 2400W max output, so around 25A. It can send more power when you overcharge the unit and goes to "Passtrough" mode (Pass from utility to your loads, without any inverter work), how much, im not sure, its not specified i think...
- Output its ok with 25A Breaker, and you are correct the LV2424 acts as a sort of "Bridge" between your Utility and House (Loads). You should size your breaker according to your cables, For 25A AWG10 its recomended, but you can use a bigger cable.

 

[madmax]

I'm not planning to do any AC input/charging... only solar. But what about AC output? Should my overkill 6awg wires leave the AC output connections on the LV2424 and go straight into a breaker box as a sort of cutoff? That's what I'm discerning, but what is the breaker size that should be used? It looks like these things are only capable of pushing 25a. Is that right? So what size output breaker should be used?

I'd recommend sizing the breaker to lowest limit of your overall system. In your case its the inverter. 25s may not trip im all conditions where the inverter trips before it (high torque start motors, for example) . A better safety margin is a 20a slow trip breaker. These will allow a few more amps for a short period of time over the 20A.

If you have ac units, I've heard larger starting caps can reduce the initial watt draw. I've found the lv2424 really dislikes starting at compressor units on a hot start (shut off turn back on) many new units have a built in timer to prevent ac hot start.

 

[Xerxes]

Question related to the item in discussion. MPP LV2424.....

Any owner out there measure the ACTUAL standby/overhead power consumption on this unit?
Is it really as listed on brochure at 50 Watts (24x50=1200W, ....1200W/4hrs= 300W of additional solar panels just to power this thing?)
Is this the standby of he PV inverter/controller, Brains, AND AC inverter-(everything)?
How doe the Eco mode work? I did not understand the manual where it says it draws power from when the loads are low -AC inverter is turned is on warm standby - as my literal interpretation is that it powers off the inverter and draws it PV/inverter, Brains, and the small AC power needs that is below the setting on the machine from the Grid supply?
A better answer ....if confirmed true by someone owning one of these ....... says it draws DC power from the batteries so there is no grid draw for the Standby Consumption, but the part about putting the inverter on standby for small AC power needs is throwing me off.

Not the questions for this post but kind of related related (same model and a power question) so not a total deviation from course .... hopefully I do not upset anyone for going off course.

I am considering sourcing one.....or some other system..... for a back up power supply due to continuing degradation of the California Electrical System -all related to greed and politics.....hence my questions.

 

[heirloom hamlet]

I'd recommend sizing the breaker to lowest limit of your overall system. In your case its the inverter. 25s may not trip im all conditions where the inverter trips before it (high torque start motors, for example) . A better safety margin is a 20a slow trip breaker. These will allow a few more amps for a short period of time over the 20A.

If you have ac units, I've heard larger starting caps can reduce the initial watt draw. I've found the lv2424 really dislikes starting at compressor units on a hot start (shut off turn back on) many new units have a built in timer to prevent ac hot start.

Well, in my case, the only motors that would ever have to startup and run would be on a refrigerator, fans or a vacuum cleaner. Also, my wires transferring my AC electricity will be huge.
So, are you saying that if I got to the point where I was pulling 21a to 25a with the LV2424, that something bad could happen to the inverter before that breaker tripped?

You would think the manual would warn you about that in detail. I'm surprised they don't even give you a recommendation on the breaker. They are so detailed elsewhere.

 

[mrdavvv]

They do recommend breaker sizing, on the middle of the manual (Parallel inverter section).

The LV2424 has an overcharge function, where it goes from inverter to utility automatically in case you exceed the 2.4kwh. It happened with mine several times... i guess it could do some damage overtime but if you correctly sized your system it shouldn't happen very frequently.

As far as im aware you should size the fuses to protect your wiring. For example in my house i have AWG14 going to the 1st and 2nd floor, so i ended up using 15A fuses instead of 25A. (Well in reality i have 2 inverters in parallel, so i have a 50A fuse, and from there it goes to the secundary 15A breakers).

 

[heirloom hamlet]

They do recommend breaker sizing, on the middle of the manual (Parallel inverter section).

The LV2424 has an overcharge function, where it goes from inverter to utility automatically in case you exceed the 2.4kwh. It happened with mine several times... i guess it could do some damage overtime but if you correctly sized your system it shouldn't happen very frequently.

As far as im aware you should size the fuses to protect your wiring. For example in my house i have AWG14 going to the 1st and 2nd floor, so i ended up using 15A fuses instead of 25A. (Well in reality i have 2 inverters in parallel, so i have a 50A fuse, and from there it goes to the secundary 15A breakers).

So, I'm talking about the main breaker that I install right off the LV2414 AC out. When it gets to the home, I'll have a number of 15a breakers dedicated to maybe 4 outlets throughout the space. Into these 15a breakers will be low amperage/watt items such as 42w .35a or less fans, typical device and computer charging, studio fridge, 25w .21a toilet, in fact the most pull this system, and any individual breaker, would have on the system would be 3 minutes on a 1500w water kettle and a few minutes a day from a vacuum.
So it sounds like you feel a 25a "Main" with 2-2-4 aluminum and 15a breakers with 14awg copper would suffice?

 

[Capt Bill]

Just FYI the manufacturer recomends 40A breaker for AC Input for a single one, and 80A for a parallel conection. Its a little hidden in page 33.

I went with 40Amp In Circuit Breakers to my LV2424s; though think 20 - 40 A matched to wire size is ok. Figure there could be need for higher than 20 A when configuring AC pass through as grid backup to Solar Watts for your Load/ while possibly also having a grid power battery charge cycle going.