We are going to be 100% off grid, looking at two EG4 6500EX-48s for the heart of our system. My hesitation is that there doesn't seem to be much real world off-grid use information on these. Can it handle a well pump kicking in at the same time the dryer, vacuum cleaner, fridge, dishwasher, hvac, lights, and air compressor are running? Or similar scenarios? I will have plenty of battery power 9x 48v 100AH. Let me know if anyone has had experience pushing these things with inductive loads/surges. I know they do just fine with normal household loads up to their rated max, but can't find anything on inductive loads. Signature techs say they will do just fine, but I would like to know it's been done successfully in the real world on the daily and did not crash. Thanks!
6500EX-48 Inductive Loads?
- Thread starter Stotts47
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Quattrohead
Solar Wizard
4500w water heater and can start a 3 ton heatpump, my actual experience.
Thanks, I assume you have other loads going as well? Lights, fridge, etc.
Quattrohead
Solar Wizard
No, those 2 big hitters are the only things connected.
SignatureSolarJames
Try Solar, the Grid will always take you back
We have tried to kill them and cannot, 15A 5.5 hp 120v air compressor (dubbed the “solark killer” by our guys) and we can run a dryer on top of it lol.
Thank you, that's reassuring, but we will have a compressor that size, with a 2.5hp well pump, dryer, dishwasher, fridge, TV, vacuum, etc. all at ounce, will two hack it, or do I need four of them? I am also seriously considering the Victron Quattro 15000KA from you guys as an alternative, but the system is much more money.
Samsonite801
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Do you know if these 6500EX have the same inverter section as the LV6548's?
I bought 4 of the LV6548 direct from MPP Solar (back when EG4 didn't exist yet, they only made GYLL batteries but no inverters yet), and the MPP Solar sales rep told me that imbalance not an issue with these (with this topology) due to each leg being on separate inverters, as long as it doesn't overload the max output of that inverter/leg, then it will never trip due to imbalance, only could trip if a max inverter/leg output was exceeded. So I bought 4 inverters to be safe (2x2), to handle my 14.5a air compressor, and any other shop loads I may put on it.
It appears like the LV6548 and the 6500EX are very similar in design, even though I know the PV charge controllers are different in their specs (can run higher PV volts and smaller gauge wire to save money). I've never heard any official stance on what the exact technical differences are from a vendor's point of view (like if they are manufactured by same company or anything, made for each sales vendor with different specs).
I still have not wired mine up yet, but I got the shop done built last week, and just moved my 4 inverters tonight (well last night), from my storage unit to the new shop, they will be installed soon finally!
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42OhmsPA
What's in a title?
Any videos of the testing?
SS should do a comparison / torture test of all the tiers of inverters you sell and set it up to also be a long reliability test.
Yeah, I was aware they are very similar and have a lot of the same components. Let us know how it goes.
SignatureSolarJames
Try Solar, the Grid will always take you back
we do need a torture test on a 2x6500ex stack
the core factors @Samsonite801 mentioned are correct, each inverter is assigned to one leg and it trips based on overload of the indiidual leg
Quattrohead
Solar Wizard
What needs to be looked at is what happens when one unit in a group either overloads or craps out.
Is one really the master that controls the whole group and can it handle loosing a slave gracefully?
RCinFLA
Solar Wizard
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The LV6548 and 6500EX have similar inverter circuitry as do most all HF inverters. The biggest difference on 6500EX is in the PV power path where there is an extra DC to DC converter between SCC boost controller output and HV DC inverter bus. This is to allow up to 500vdc PV inputs while feeding the 250vdc HV DC inverter bus for 120vac output of inverter. (230vac only inverters have about 500vdc HV DC internal bus)
HF inverters do not handle poor power factor loads as well as LF inverters.
With a poor power factor load there will actually be reverse current flow in the AC waveform during a fraction of the AC cycle. A high frequency inverter pushes this short reverse current to the HV DC bus capacitors. A low frequency inverter pushes the short reverse current to the batteries.
When the HF inverter HV DC capacitors get this short back current push its voltage rises a bit causing the battery to HV DC converter to immediately reduce or cease its output. This sudden near zero load bouncing on the battery to HV DC converter can cause instability in the converter.
The ability for a HF inverter to take this momentary back feed current depends on its HV DC filter capacitor values and feedback control stability of its battery to HV DC converter. Generally, on the cheaper HF inverters, the HV DC filter capacitor is only about 500-1000 uF and a load power factor worse than about 0.7 to 0.8 is getting near their limit. You will see rapid variations in the AC output voltage level when it starts to become unstable.
A single-phase induction motor has a large startup surge current and a very poor inductive power factor (<0.5) during the startup surge current period lasting close to 0.5 seconds. Run power factor is in the 0.7-0.9 range depending on the motor and its actual mechanical loading.
HF inverters do not handle poor power factor loads as well as LF inverters.
With a poor power factor load there will actually be reverse current flow in the AC waveform during a fraction of the AC cycle. A high frequency inverter pushes this short reverse current to the HV DC bus capacitors. A low frequency inverter pushes the short reverse current to the batteries.
When the HF inverter HV DC capacitors get this short back current push its voltage rises a bit causing the battery to HV DC converter to immediately reduce or cease its output. This sudden near zero load bouncing on the battery to HV DC converter can cause instability in the converter.
The ability for a HF inverter to take this momentary back feed current depends on its HV DC filter capacitor values and feedback control stability of its battery to HV DC converter. Generally, on the cheaper HF inverters, the HV DC filter capacitor is only about 500-1000 uF and a load power factor worse than about 0.7 to 0.8 is getting near their limit. You will see rapid variations in the AC output voltage level when it starts to become unstable.
A single-phase induction motor has a large startup surge current and a very poor inductive power factor (<0.5) during the startup surge current period lasting close to 0.5 seconds. Run power factor is in the 0.7-0.9 range depending on the motor and its actual mechanical loading.
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Wow, thanks for the hardcore knowledge download, so does having higher output capacity HF inverters make up for the shortcomings? For example will a HF inverter with12kw of output do significantly better than 10kw on inductive loads, or do I need to jump to 20kw to see a difference, or it doesn't make much difference? For example 4x 6500Ex vs 2.
Quattrohead
Solar Wizard
I think it just depends on the inverter.
What I do know is that LV6548 type inverter has been around for a couple of years and it seems to be very well regarded.
Mine have no issue with 4.5kw of water heater and starting my (bitch to start) 3 ton heat pump at the same time.
Growatt 6000T was 99% ok with my heatpump (did growl on startup lol) but once in a while it failed and I would have to wire it back to utility to kick start/free it up again and the poor old Sol-ark 9-12k just hated it lol.
What I do know is that LV6548 type inverter has been around for a couple of years and it seems to be very well regarded.
Mine have no issue with 4.5kw of water heater and starting my (bitch to start) 3 ton heat pump at the same time.
Growatt 6000T was 99% ok with my heatpump (did growl on startup lol) but once in a while it failed and I would have to wire it back to utility to kick start/free it up again and the poor old Sol-ark 9-12k just hated it lol.
SignatureSolarJames
Try Solar, the Grid will always take you back
we have better surge than the deye per watt in the 6500ex
Samsonite801
Solar Wizard
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Even though I have 2x2 of the LV6548 for my shop install, it should have no problem starting most loads, I am still going to add soft starters wherever I can just to work it from the load-side of the equation as well, I figure it will hammer on the inverters less to try and dampen the spikes. My theory is it can help the inverters to last longer by not hammering on the transistors as much.