warm breaker, can I increase size above 60a ?

[zanydroid]

Do you have anything that shows power factor? I think Emporia has it internally, not sure if it's accessible via the app, I've never seen it, but maybe if you use Home Assistant connector you can pull it. Maybe these minisplits are cursed and have zero PFC.

Another possibility is bad connection at the breaker causing it to heat more than expected (like busbar or wire terminal). Is the breaker fast-tripping or slow-tripping after some runtime?

 

[Texican]

6000w/240vAC=25a

ETA: If you are running 2-6500w units as split phase you are just about maxed.

OK maybe this is also what Im confused about
solar assistant and emporia both showed using 6000w
lets say all of the load is 240v
each of the minisplits are only using 15a, running 240v, thats 15a on L1 from 1 inverter and 15a on L2 from the other inverter
So running 2 minisplits at 15a each, I have 30a on L1 from one inverter and 30a from the other inverter
I thought the inverters can output about 54a each at 120v

what dont I understand about split phase so the system is maxing out at 25a ?

 

[Mattb4]

OK maybe this is also what Im confused about
solar assistant and emporia both showed using 6000w
lets say all of the load is 240v
each of the minisplits are only using 15a, running 240v, thats 15a on L1 from 1 inverter and 15a on L2 from the other inverter
So running 2 minisplits at 15a each, I have 30a on L1 from one inverter and 30a from the other inverter
I thought the inverters can output about 54a each at 120v

what dont I understand about split phase so the system is maxing out at 25a ?

Sorry my error. I made the mistake of thinking each AIO was seeing 6000w. Instead they are seeing only half each. Each leg of your 240vAC would indicate 12.5a. if you tossed a clamp on meter on either L1 or L2.

At any rate the problem seems to be your breaker and not your load.

 

[Texican]

Sorry my error. I made the mistake of thinking each AIO was seeing 6000w. Instead they are seeing only half each. Each leg of your 240vAC would indicate 12.5a. if you tossed a clamp on meter on either L1 or L2.

At any rate the problem seems to be your breaker and not your load.

ok thanks

 

[schmism]

the 6548 inverters run 120v each so 6500/120 is about 54 amps max output for each inverter

Its my understanding thats off both legs. so 25A L1-N and 25A L2-N I am fairly certain you can not pull 50A off L1-N (0A L2-N)

it matters when you start stacking 110v loads on a 220v split phase system.

 

[Supervstech]

Its my understanding thats off both legs. so 25A L1-N and 25A L2-N I am fairly certain you can not pull 50A off L1-N (0A L2-N)

it matters when you start stacking 110v loads on a 220v split phase system.

Amps in a 230V system do not add up.
If you have 240V on l1 to l2, you measure 25A on either l1 or l2, you have 25A...
Not 50...

 

[schmism]

Amps in a 230V system do not add up.
If you have 240V on l1 to l2, you measure 25A on either l1 or l2, you have 25A...
Not 50...

I understand that. however the quote that i copied from OP's post suggested 54a of 120v. I was clarifying that you cant pull 54a off one leg.

people have a tendacy to stack 40A of 120v (4800w) of demand off one side of a 220v inverter and then get confused when it wont power it ("but its below the 6kw output")

 

[Texican]

is there a max imbalance between L1 and L2 that would cause either the inverter to shut down or the main breaker to trip, when total usage is below max on both legs ? in other words a breaker trip or inverter shut down just due to imbalance rather than overload ?
this would be in a dual inverter split phase setup like mine
I may need to verify how off balance I might be and move breaker positions

 

[schmism]

is there a max imbalance between L1 and L2 that would cause either the inverter to shut down or the main breaker to trip, when total usage is below max on both legs ? in other words a breaker trip or inverter shut down just due to imbalance rather than overload ?
this would be in a dual inverter split phase setup like mine
I may need to verify how off balance I might be and move breaker positions

I was thinking that the LV6548 was a native 220v inverter. IT is not. As a single unit it ONLY supports single phase. so yes you can pull 54a off one L-N connection.

So consider that your max per-leg current. on 220v (dual parallel split phase) each unit will put 54a into their "side" of the 220v.

so per my previous example, just have to move up in power, your total power is 13kw, (for example you cant draw 8kw off one leg even though its well below your 13kw system limit)

As to your question, yes if you pull more than 60a off one side of the 220v breaker it should trip. Your inverters should alarm an overload if you pull more than the 54a off them, likely trigger auto-shutdown. On my growatt I can set an auto restart which I have enabled.

 

[Supervstech]

Yeah, if you are pulling 24A combined from the minisplits, AND you have a few 120V loads on one leg... both inverters will overload. The breaker can trip...

 

[Hedges]

I don't go and try and correct Hedges lightly, but no. Breakers are rated to trip at their rated current, not 80%. The trip curve in the data sheet for any AC breaker will show this.

True, rated to trip at rated current under ambient. But don't get mad if they trip above 80%

Intermittent to 100% (and briefly above) is fine.

I think what is tested in production is trip time at reasonable overload, and fast trip (typically > 5x rated.)
Holding without tripping would not be tested in production, takes too long.

The NEC says that you should not size permanently installed equipment to draw more than 80%, but that's a different issue.

Permanently installed or multiple portable devices, if loaded above 80% for hours on end, you risk tripping the breaker. Hot day, wire connections heating up would contribute. Maybe breaker aged after multiple trips.

https://download.schneider-electric.com/files?p_enDocType=Technical+Drawing&p_File_Name=730-13.pdf&p_Doc_Ref=730-13&_ga=2.224297115.1004013282.1690304426-1658668532.1687444866

At 25 degrees C.

 

[Hedges]

but the amps showing 12a each for 25a looked right, but total usage showing double amps of 50a
has me wondering WTH ??
I dont know whats up

6000w/240vAC=25a

Assuming PF = 1.0

my 2 ton mini splits run at 240v and are spec with 20 amp breakers

Mini-split meaning inverter drive?

Heating of wires and breakers will be greater with poor power factor of rectifier/capacitor front end.
I would have expected 20A breakers to trip sooner than 60A, but "coordination" may differ.

For 25A expected load to trip 60A breaker would take seriously low power factor, but not impossible.
Combined with other loads as mentioned, easier to do.

Clamp ammeter and IR thermometer at breaker is the first thing to check.
How you could evaluate power factor and waveform, I'm not sure. I would use my oscilloscope and current probe.
Temperature rise of a series resistance element would be a direct measure of the issue, but would need to calibrate it.
A true RMS ammeter I think would do what is needed; not all meters are.

 

[Zapper77]

I dont know if my emporia vue is giving me bad info or what.
no way the mini splits use over 20 amps, they have 20 amp breakers, I think they are around 15a max running
so both running should not be over 30a load max

with the emporia on 240v circuits, you put a ct on 1 leg and tell the system to double the usage

when the 60a breaker tripped, I looked at emporia and it showed each mini split using about 12a and 3000w
so about 25a total, but it showed my total usage at about twice that...50a and 6000w and not much else was running, just lights etc
so I frankly dont know what the issue is/was

thats why Im wondering... my system should be able to run 3 mini splits at 15a each/240v all at the same time ??

the emporia data showing 3000w per mini split and 6000 total looked right, nothing much else running,
but the amps showing 12a each for 25a looked right, but total usage showing double amps of 50a
has me wondering WTH ??
I dont know whats up

anyway for now I rewired 1 minisplit back to the grid, and ordered a changeover switch so I will be able to select either grid or off grid for 1 of the mini splits and will not run both off grid till I figure this out
may change the 60a breaker just to rule out an issue

seems to me running 2 at 15a each should allow plenty of room for other appliances

Does emporia show power factor? I heard that these cheap minisplits have terrible PF...in that case what is the VA showing.

Edit: 6548 screen should show VA right after watts

 

[niktak11]

You have to have a breaker MARKED that it is rated for higher C...
All residential breakers are 60C...
If you have a breaker marked for a higher temp, then you can follow that column on the chart... as long as BOTH ends of the conductor equipment is so marked...

I think most of them are 75C these days. If the breakers on both ends are rated for 75C and the wire is too then you can use the 75C ampacity column unless there are other derating factors. 75C 4 AWG aluminum is rated for 65A and you are technically allowed to round up to the next "common" breaker size of 70A. If it were me I'd think about replacing it with larger wire if possible.

 

[zanydroid]

Does emporia show power factor? I heard that these cheap minisplits have terrible PF...in that case what is the VA showing.

Edit: 6548 screen should show VA right after watts

It gathers the data internally and does correct W calculation. This has been confirmed by Emporia customer support numerous times, you can Google for the knowledge base and social media posts they’ve made. I haven’t attempted to access the data.

 

[ksmithaz1]

True, rated to trip at rated current under ambient. But don't get mad if they trip above 80%

Intermittent to 100% (and briefly above) is fine.

I think what is tested in production is trip time at reasonable overload, and fast trip (typically > 5x rated.)
Holding without tripping would not be tested in production, takes too long.



Permanently installed or multiple portable devices, if loaded above 80% for hours on end, you risk tripping the breaker. Hot day, wire connections heating up would contribute. Maybe breaker aged after multiple trips.



At 25 degrees C.

The guides say up to 100% for up to 3 hours. My general experience is with Data center loads that gradually umm, grew over time. I've seen 90+% loads run for a long, long time, however in every case we were forced to figure it out with an amp clamp and a temp gun once we destroyed the breaker from overheating it for months. (You can sure pack a lot of those new 1U boxes in when you drop down from 3U) To Hedges point, you really don't want to run 3 hours over 80%, because the breaker will get hotter than normal and degrade over time. Once you heat a breaker more than once or twice to trip you are going to want to replace it. Most breakers will handle 120% for a few minutes. A lot of equipment likes to use oversized breakers to handle in-rushy kind of things. After dealing with computer crap, overloading circuits for so long (densities kept increasing as equipment swapped) I try to really match the breaker to the expected load for anything with a high draw. If for whatever reason the breaker trips, that will make me go look and see what the story is, before I have something running way out of my expectation range.

 

[Hedges]

Just when I had completed wiring a 50A range outlet to power the bench in my new lab (spare bedroom), I had to go and find a 60A outlet and welder power cord:



Especially considering I had put in a 60A breaker (what I found on hand), I was inspired to upgrade the outlet.
60A x 0.8 = 48A continuous, that got me thinking I should use DIN rail Midnight/CBI breaker; then it can be 60A continuous:



I'm wiring up a QO breaker panel with several outlet boxes attached, 20A to 50A outlets, NEMA & TwistLoc, for instruments and testing GT PV inverters.

I built a breaker tester to see what was going on with the Schneider 63A multi-9 breakers that tripped below rating on me. (quantity I bought used). Some ran considerably hotter than others and tripped below rating. I put the best of them back in the PV circuit, then later replaced with the magnetic-hydraulic shown above.

Testing Magnetic-Hydraulic circuit breakers

I've built myself a circuit breaker tester. I assembled three transformers into a 3-phase wye auto-transformer, and by means of a breaker and cord/plug it can be repurposed into a current multiplier. A breaker connects X1 to H2 and H3, providing 4.7x current boost on X2 paralleled with X3...

diysolarforum.com

 

[Texican]

I replaced the 60a breaker today, I also found that when I installed the breaker I had been careless and allowed some of the AL wire strands to be cut off when stripping the insulation, thus reducing the size of 1 of the 2 hot wires to the breaker to be even less than #4 awg
fixed this problem as well as replacing the breaker
2 remaining issues I will address this weekend

I will be installing this changeover switch which will allow me to switch one of the minisplits from off grid to grid easily
https://www.mqtekusa.com/product-pa...anual-transfer-switch-in-a-ul-csa-listed-encl

I will run a test using both minisplits off grid as well as other loads and try to max out the system and see if the breaker trips