superdiy

The minimum charging current on the 3K24V is 20A and since most battery manufacturers suggest a maximum charging current of 10% of the Ah rating (20h) of the battery bank, you should actually not connect a smaller bank than 200Ah - and that is only if you change the charging current to 20A instead of the 30A default. Some battery manufacturers advise that you can charge their batteries at up to 13% of the Ah rating (20h) which would give you an absolute minimum battery bank of approximately 150Ah.

I'm certainly not one of the wise men, just trying to assist where possible... Secondly, I'm not an expert on the lightning thing either. You can install all kinds of lightning protection, but even with all the protection in place a direct strike will most probably kill the greater part of your system in any case. Maybe some others have different opinions.

The above is still not clear. It would be great if someone can shed some light on the proper (legal) way to do this.

Nope, any more information yet? My old UPS batteries are starting to fail one by one.

Thanks Plonkster for your detailed reply. I am no battery expert and could not have explained it better either. In the installation I did with the Trojans, they should have enough time to charge in-between "load-sheddings" - they are not cycled daily, but as per your explanation the Axpert - Trojan combination might not be ideal when cycled daily.

I have the same experience with DTM - complete and utter rubbish.

You get relays with AC coils and relays with DC coils. DC coils usually have higher resistances while AC coils usually have lower resistances (because on AC the impedance comes into the equation). You should be able to energize a DC relay coil with an AC voltage considerable higher than the DC rating of the relay coil.

Someone at work also wanted to connect the smallest possible battery bank to the Axpert to make use of PV mostly. Since the 3KVA and up Axpert models cannot charge the batteries at less than 20A, the smallest battery bank you can actually connect to it would be a 175Ah (20h) bank. That is charging at between 10% and +-13% of the 20 hour amp-hour rating. I would not recommend anything smaller than 170Ah - definitely not 7Ah.

I think something similar happened to Wetkit with his infini. On the infini software there is a setting where you calibrate the grid power - default is 0, but it can be adjusted more positive or more negative. With "feedback" disabled it still feeds back a little (when set to 0) and only when I set mine to -165W it does not feed back anymore. I'm not sure if you have a similar setting on the Imeon, but worthwhile to check. Good luck.

I've used the ISO7220's in a USB-to-DMX cable, but I see they are now much more expensive than what I paid about a year ago.

As long as it is single-sided I might be able to assist. That is for prototyping - not large scale productions runs please.

This looks to good to be true.

In bypass mode the limitation still applies - the inverter will start to complain and eventually switch off (overload situation).

Then in that case it should not be a problem.

" they are not designed for the higher voltages." The purpose of a fuse is to isolate a circuit in case of a fault condition, that is when the current flowing in the circuit is larger than the rating of the fuse. When a DC circuit is disconnected, e.g. in a switch, circuit breaker or fuse, while a high current is flowing in that circuit, it causes an arc. The higher the voltage between the two disconnected points, the bigger the arc will be and therefor the points where the circuit is disconnected, inside the switch, circuit breaker or fuse, needs to be further apart for higher voltage circuits in order to help to distinguish the arc. If you are using switches, circuit breakers and fuses with voltage ratings much lower than the voltage it needs to isolate, the arc will not be distinguished properly or soon enough and that might cause overheating, melting and possibly an explosion. Edit: Plonky, you beat me to it with 1 minute.

You cannot connect a grid tie limiter to the infini - it does not support it - that simply means that the infini will push all available power to the grid, up to the maximum as configured in the software. It will stop pushing to the grid when the grid fails. It will only push excess power to the grid - the balance of the load and the battery charging power.

The Plus model infini can utilize up to 4500W from the PV panels. That is 3KW output + battery charging + internal consumption + losses. You can always add more panels to ensure that you have more than enough PV power available under less ideal circumstances, but the inverter will only utilize up to 4500W of it. The infini is a true hybrid, it will charge the batteries while supplying the load and be able to feed the balance to the grid - all at once.

Thanks for clearing that up.

The 360Ah bank should not be charged at more than 10% (maximum 13%) of the Ah rating => 36 A (max 47A) I'm not sure how the parallel Axperts handle the charging aspect, maybe someone else can shed some light on that. I assume the primary inverter (only) will handle the charging. You'll have to adjust the maximum charging current (setting 2) to 40A, if you have the option, because if I understand the manual correctly it seems that the lowest possible option for this setting for the 5KVA Axpert is 70A? If 70A is the lowest possible option, then use that. Change the Maximum utility charging current (setting 11) also to 40A. If both (all) the inverters simultaneously charge the batteries you'll have to set setting 2 and setting 11 to 20A (per inverter).

Hi Henkt, welcome to the forum. If you set the inverter to USR, you have to configure all the battery-related settings yourself - you'll have to get the datasheet for your specific batteries and change all the battery-related settings according to that. The 60% SOC thing was explained in various threads already and it basically comes down to the fact that these inverters don't give you an accurate SOC indication and you simply have to add a proper battery monitor e.g. a Victron BM to get a more accurate SOC. The 60% SOC reported by these inverters are actually still 100% or almost 100% charged (>= 2.10V / cell). These inverters only measure and compare voltages when indicating SOC and for Low-V cut-off etc. and that is actually worthless, since the battery voltage will drop depending on the load at the given time - when the load is reduced the voltage will rise again and therefor the Low-V cut-off should not be set too high to avoid unnecessary inverter shut-offs. On a 48V system, you should set the Low-V cut-off to 44V or even 42V to allow for heavy loads.

Hi Manie, welcome to the forum. Glad to see another Delphi developer - not many of us still around. I'm also going to give it a go at some stage, but I have a bit too much on my plate currently. Please keep us posted if you make any progress.

I'm not sure what your question is, does the linking of the negatives bother you? Since they've linked the negatives in the drawing (as opposed to the positives) it might cause confusion, but the negatives of those batteries are connected to the positives of the batteries right next to them and that is the mid point between the negative of the battery bank and the positive of the battery bank. You connect that "mid-point" to the BM in order to measure the upper and lower parts of the battery bank. You have to connect the mid-points of all strings together in order to measure any difference in mid-point voltage accurately - if you only connect the mid-point of one string to the BM, and there is a problem in another string the BM will not detect a problem. Traditionally you should have one fuse in series with each parallel string of batteries - does not really matter exactly where the fuse is located. By connecting the the mid-points of all strings together, you actually need to have a fuse in series with each string on each side of the mid-point e.g. between the positive of each string and the positive bus-bar and between the negative of each string and the negative bus-bar, just in case something goes wrong in any one of the parallel strings on either side of the connected mid-points.

Yes, the standard thermostat slides into a, as you call it, "pocket" - it is not in direct contact with the water and thus you don't have to empty the geyser before you pull it out. The thermostat is about 6mm diameter, so I doubt if you will get a TO92 LM35 inside the exsiting probe, unless to "trim" the LM35 to a smaller version , but you can perhaps cut the probe's tip off and run the wiring inside the probe and add the LM35 to the tip of the probe, maybe use some Pratley steel and shape it to the same diameter as the probe.