Ive had my victron system for a bout 2 years now. It never tripped the prepaid meter. About a month ago it happened and today again. So I have to get the municipality out again to come and reset it.
It happens when my grid voltage is quite low 210V and my inverter disconnects and reconnects to the grid. At that stage typically I am using 5-8kw of power.
Has anybody else had a similar problem? I run two 5kva multiplusses in parallel now.
Any help or advise would be greatly appreciated. This is a massive nuisance.
Some prepaid meters are quite sensitive and will trip no matter which inverter and what settings you connect to it, but since it doesn’t happen that often, I guess that’s not the case here.
With inverters in parallel, the control loop gets even slower, which is likely the case here. It just takes too long to try and pull back the power when this happens. (although this is kind of an edge-case as it’s not supposed to be an issue when handing over back to the grid)
My suggestion is to check whether you can get them to increase the grid voltage so that you don’t have the disconnect, or to get a tripconnect like @TheTerribleTriplet that disconnects before the multiplus would.
I think it is due to the change in voltage that there is a momentary power feedback. My grid disconnect voltage is 205A and reconnect is 210A since the area I stay in has low voltage problems. So when it connects to the grid the house is runnnng at 230A and the grid at 210 and then there is a momentary big push of power into the grid. I can unfortunately not see this though on the VRM data since the logging is too slow.
If this is indeed the problem - maybe I should lower my inverter output voltage from 230A to 220A?
P.S. I spoke to the electrical engineer in charge of these things at our municipality just now and he says my area needs a mini substation replacement to sort out our low voltage area problem - but it isnt going to happen.
PPS. My prepaid meter isnt super sensitive. I have seen many times where small amounts of power is pushed back into the grid for short periods of time. At some stage the setup was wrong and it even sent a constant 300W back into the grid. This didnt trip the meter.
You can set the voltage at which the multi connects and disconnects. Mine is set to disconnect at 205V and reconnect at 210V. If you have it set very low we have seen that the transfer of power when the grid drops away is not so smooth. I.e. appliances turning off etc.
Let me put it another way. Your meter trips, probably because of something from the inverter, right?
So if the Tripconnect disconnects first, that is like switching your inverter “off” at its switch, so then nothing can flow back to trip the meter on the main DB?
I dont see how the tripconnect will help - as it only sense voltage and current and not direction of power flow? Can you make it disconnect on negative current flow?
My guess is that the parallel multis just react too slow when the grid connects and they are inverting a lot of power and there is a big voltage difference between the grid and the multi.
I think the root of my question is, is it possible that a lot of power/current will flow into the grid momentarily if you connect to the grid and your inverter is running at 230V while the grid is at 210V. With a parallel multi setup providing a lot of KWs. P.s this also doesnt happen when the multis are not running several air cons etc.
I hear you, I do, but thinking outside the box here.
They work on volts, too high, too low, and if the amps are exceeded. So a simple device.
When the grid reconnects, you tell it to wait the max time, say 5min, before the DB is connected to the grid again. After that, the Victron takes another 60+ seconds to sync.
The idea is to keep the inverters away from the grid, so that the grid settles, or whatever it needs to do, before they connect, in a controlled manner, as a test.
Alternatives are:
Take one inverter off, and try again?
Get the Munic in each time it happens?
Get another meter … or the issue is fixed at street level?
… ?
Your equipment meets the NRS required standard.
Now the munic needs to adhere to that standard too.
Silent benefit, the Tripconnect protects your stuff against Eskom woes, so there is that too. So if you installed it, and the problem still persists, at least you have better protection in any event for worse cases later.
Probably yes.
We are talking in milli seconds here for stuff to throttle back etc.
If the muni has not yet come to do the reset - depending on type of meter they might be able to tell you the reason for the trip so ask them (this in itself may require the muni staff knowing about it and being willing to do it). For some meters this involves inputting a bazillion digit code, or special key sequence. You might even be able to find some of the useful codes for your meter online (no, “unlimited units” is not one you will find… )
This might at least help you narrow down what is actually happening according to the meter.
I had one of the electrical engineers at the municipality help me. Very helpful and Im impressed with their service.
He told me the meter I have - Landis & Gyr cashpower has nearly no support locally and they really struggle to do anything with it. If someone knows what codes to put on the Landis & Gyr in order to check why it tripped it would be a great help.
shot in the dark if correct model but have a look from page 29 on. If not wanting to download pdf’s have a look here
“i 014” might be relevant to tell you what the chances are that it is tripping on a power limit (slight possibility for this especially with the low local voltage)
The following should also tell you much more: (but without the manual next to you the output will be difficult to decipher)
i 030
i 031
i 035
i 037
Some of those meters do have a feature for significant reverse power, which sends it into tamper mode. But from what I remember, you really have to send a LOT of power in reverse for a long period of time before it will do that. It’s much more forgiving than the Conlog meters (although the Conlog meters only punish you with a 30 second disconnect).
Edit: I note that the diagnostic registers in the manual will give you an indication if Significant Reverse Power was the reason. You can also turn it off, so reverse power doesn’t cause tamper, though of course you need the correct code for that.
Edit 2:
A significant reverse power condition will be flagged when there has been a continuous
reverse power measurement equivalent to 50Wh.
So that is 50 times 3600, 180kJ, which is 36 seconds at 5kW, 12 seconds at 15kW. For that inverter combination, 8kW is max it will do grid tied, that’s 22.5 seconds. That’s within the domain of possibility.
Thats still a LOT. Hard to believe it can be that much for so long. Pity I reset the meter before checking the status of the tamper detection.
The electrical engineer advised that we replace it with a conlog - it sounds like they have the ability to set the level at which it triggers a 30sec disconnect. Even if you cant set it, a few disconnects will certainly be better than tripping the tamper detection.
The ESS algorithm is actually not far off. I’ve measured 15 seconds pretty consistently, and as much as 27 where the load wasn’t a nice constant value. And believe me, a LOT of work has gone into this in the past, and a few times I backtracked to the old way because someone complained that now it is unstable.
@tvic, do you use a grid meter, or are all the loads on the output of the Multis? I ask, because if you’re already not using a grid meter, there isn’t much to be had in the way of speed anyway. I’d seriously consider replacing the meter, or turning off that feature.
With Conlog, The Muni needs to write a letter to conlog to supply you with a token to disable Revers Flow Detection. Conlog Straight out the box will also trip, but not go into a tamper mode, its will reconnect a minute or two later.
Apologies for yet another reply, but if the grid code is set to NRS097 the Multi is in any case prohibited from feeding in full power, and will only ramp up feed-in over the next 5 minutes. So the odds of a 22 second full-power feed-in is rather low.
plonkster - I dont use a grid meter. Everything is on the AC out of the multis. When I installed the second parallel multi I took out the grid meter - it was the entry point of a lightning strike that took out some of the components. So I took it out first opportunity that arose.
)