Brucey
Solar Wizard
My understanding is the risk of this happening can be mitigated by design? I.e the Victron autotransformers?
EG4 18k caused massive voltage spike
- Thread starter scottlebus
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Even with auto-transformer you may have loose neutral connection falling off somehow. This would protect against those wiring mishaps. Now thinking about it some more, only one leg of 240V inverter output needs to have a solid state relay before the auto-transformer. This way it kills power to both sides of 120V loads at once. Inductive spike or neutral unbalance voltage can be clipped by passive TVS diode clamp since it only needs to dissipate one half of AC cycle and it does not need to crowbar the inverter. Edit: this can also be done with remote trip AC breaker like @Hedges suggested since TVS diodes will clip the peaks anyway as long as the breaker opens in under one half of AC cycle.
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SpongeboB Sinewave
Solar Enthusiast
That particular SPD will not help at all. They are 3 wires put into some sand, basically.
Here is a comparison of a MOV based SPD lightning arrestor and a Delta.
boB
SpongeboB Sinewave
Solar Enthusiast
Which inverter was this that put out the surge voltage to break these things ?
I think I just saw that it was the EG4 18K. Nevermind...
boB
EG4 18k
Markus_EG4
I am from Germany. Don't mean to come off rude
I have looked at the logs
i have looked at all the logs on the inverter and no change in voltage or Frequency happened. Do you have a specific time this happened maybe I’m not looking back far enough
Quattrohead
Solar Wizard
Or you can just follow the manual and install it properly.
Hedges
I See Electromagnetic Fields!
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Up to you whether EGC or neutral. You get three wires, and it is either 2 or 3 MOV, not sure which.
Their behavior is to clamp to some voltage, whether 200V or a few hundred.
Sustained voltage will burn them up, so MOV are available in series with PTC (or is that poly?) fuse. 2 or 3 wire. The Midnight ones have two color LED, to show "protecting" and "failed" so you know power is on, and if they need to be replaced.
Pretty funny.
Looks like same model Delta the forum member showed.
"Any surges over 2500V most likely damages"
Equipment normally gets tested for kV spikes, so 200V clamping is useful but so is 1000V clamping. The 200V MOV will get worn out sooner, because it will experience more hits. You can install a couple of different voltages; then when one shows failure the other will still be protecting.
I discovered the Delta's lack of clamping on my own, then reached out to Midnight to see how they test. (They didn't share any tips, just said, "use the data from our SPD tech sheet".) Good they've got videos of in-house and lab tests for people to watch.
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ksmithaz1
Solar / EV Junkie
I've had mine running since early June. I've had myriad issues, EG4/SS does not pay me or anything. I can also be the biggest pr*ck on the planet if I've been mis-treated by a vendor. SS phone support has been abysmal for me in the past. Though seems to have improved dramatically over the last few months.
I've never recorded any kind of a significant voltage spike from my inverters. I've been monitoring Volts, Amps, Frequency, and KWH on my main panel feed since 6 months before the solar was installed. ... Thus I have a pre-inverter baseline as well. In the summer, right after they were installed, my units were cycling on and off switching at least twice every day, as batteries depleted, and recharged. I was also fiddling with it not infrequently putting the units in and out of standby. I had a number of phase match issues from running a transfer switch and not using the grid tie lugs, some of those switches created some nasty noise from the HVAC until I came up with a work-around to stay in-phase with the grid. I even had a firmware bug associated with the batteries that caused the inverter to cycle on and off repeatedly every few seconds (still testing to see if this is resolved, and get a better handle on it, it's an esoteric set of events). The bulk of the rest of the issues I've had have been fixed or almost completely mitigated by firmware upgrades.
Thus I would struggle believing that a properly installed inverter would create a spike capable of frying a circuit board in an appliance simply because it was cycling. The low voltage part of the circuit designs in major appliances, HVACS, Microwaves, Stoves, Washer/Dryer's are generally extremely tolerant and behind some step-down transformer/circuit. I've had my house hit with a direct lightning strike in the past, that actually took out an incandescent light bulb, that never fried any major appliance electronics in an all electric home. It did make the wifi radio the antenna was attached to explode, the antenna fragments were all over the neighborhood, it took out the router behind it and fried a port on the switch, and pretty much scared the pee out of everyone in the house, the HVAC was running, the TV was on some breakers popped, so I do see the possibility. I am just struggling with this inverter doing it because the way it's engineered there is a delay while it verifies it's ouput is stable before it engages the relays. In fact, the output is generally more stable from my inverters than from the grid.
So I've seen a number of people report these kinds of incidents with "inverters", not just the EG4, but if you are having these kinds of problems, I'd put a sensor on your feed lines, and re-check all of your wiring and grounding. Frankly the worst spikes I've seen (besides lighning strikes) are from the power company after a power outage. Got nuthin of note from the inverters in my logs. YMMV.
ksmithaz1
Solar / EV Junkie
Neutral and ground are the same thing after all, just tap 110 from the bare copper on the 240 feed line it'll be fine.
I'm still waiting till we have evidence to draw a conclusion here. Going to lock thread tomorrow if no response from OP
As I have been looking for about a 5k system, this unit has not even been on my radar. Is it a single phase or are we dealing with a three-phase unit?
I've lived in an LDC where the power company did not always correctly wire their transformers to ground. It was sometimes possible to get transient (not surge or spike, but constant for a period of time) voltage of 120V on the ground wire (as compared to true earth ground), and I forget if it were 270V or 380 or something between two of the phases. Between another two it was the normal 230V--just depended which phase was chosen. In any case, if one wires one phase of three to ground, this sort of thing can happen. I'm sure the engineers here will understand and be able to explain it more clearly. It's a real bummer when the grid power is done this way!
However, this sort of problem does not sound likely as possible in the case of this thread, because those inappropriate voltages would exist as long as the wiring was setup that way, not merely for a surge.
I've lived in an LDC where the power company did not always correctly wire their transformers to ground. It was sometimes possible to get transient (not surge or spike, but constant for a period of time) voltage of 120V on the ground wire (as compared to true earth ground), and I forget if it were 270V or 380 or something between two of the phases. Between another two it was the normal 230V--just depended which phase was chosen. In any case, if one wires one phase of three to ground, this sort of thing can happen. I'm sure the engineers here will understand and be able to explain it more clearly. It's a real bummer when the grid power is done this way!
However, this sort of problem does not sound likely as possible in the case of this thread, because those inappropriate voltages would exist as long as the wiring was setup that way, not merely for a surge.
Motors more often "fry" via a brownout than a surge. If the unit keeps logs of the voltages, I would be looking for undervolt rather than overvolt.
In this other thread concerning 'EG4 18KPV frying furnace transformer when PV power is low', in post #21 Hedges wonders if a bad waveform might be the culprit. Could that be a possibility here?
https://diysolarforum.com/threads/e...transformer-when-pv-power-is-low.72344/page-2
https://diysolarforum.com/threads/e...transformer-when-pv-power-is-low.72344/page-2
Zwy
Emperor Of Solar
There was another thread recently about problems when PV power was low but I could not find it. Inverter would shut down and start up repeatably. The solution was either update firmware or a change in settings that only Lux or EG4 could do.
Gavin Stone
Solar Addict
I have shut my 18kpv unit down and restarted it multiple times in about any configuration you could imagine. I’m pretty certain that’s not the issue.
But we would need photos to confirm either way.
But we would need photos to confirm either way.
Alright, locking this thread. Still no evidence posted. If you are the OP, please create a new thread with actual evidence to substantiate your claims. Thank you
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