Rapid Shutdown (RSD) on the EG4 18Kpv

FYI I just connected my eg4 18kpv today with 2 arrays of only Tigo TS-4 A-2F and one array of mixed 6 panels running Tigo TS-4-A-2F and 4 running TS -4-A-O AND TO MY SURPRISE the inverter turned on the TS-4-A-2F on without the Tigo RSS Transmitter!! I have now removed the RSS Transmitter and coils and reboxed it for return/resale to whoever and my arrays are
happily pumping out plenty of power without ANY ADDED RSS Transmitter and the RSS button on the side of the 18kpv works
Great! one note i didnt expect was the optimizers to continue to pump out their voltage thru the mixed system of TS-4-A-2F
(the optimizers were in the middle of the string with TS-4-A-2F on each end of the string) so when i measured the string voltage back at the inverter prior to connection i got 3 v , 3 v and 140volts on the last MIXED string!! SUPRISE!! Anyway everything works fine and i have a TAP/CCA on order to satisfy the rapid shutdown

jjww said:

FYI I just connected my eg4 18kpv today with 2 arrays of only Tigo TS-4 A-2F and one array of mixed 6 panels running Tigo TS-4-A-2F and 4 running TS -4-A-O AND TO MY SURPRISE the inverter turned on the TS-4-A-2F on without the Tigo RSS Transmitter!! I have now removed the RSS Transmitter and coils and reboxed it for return/resale to whoever and my arrays are
happily pumping out plenty of power without ANY ADDED RSS Transmitter and the RSS button on the side of the 18kpv works
Great! one note i didnt expect was the optimizers to continue to pump out their voltage thru the mixed system of TS-4-A-2F
(the optimizers were in the middle of the string with TS-4-A-2F on each end of the string) so when i measured the string voltage back at the inverter prior to connection i got 3 v , 3 v and 140volts on the last MIXED string!! SUPRISE!! Anyway everything works fine and i have a TAP/CCA on order to satisfy the rapid shutdown

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Correct, the 18kpv has the capability out of the box to send the "heartbeat" that the RSS transmitter does. The optimizers will work (as an optimizer only) until connected to a CCA. Once connected to a CCA, they add the RSD functionality. After they've been paired with the CCA, they will not produce power without the CCA/TAP active, because without the signal.. it will assume "RSD" has been activated. That said, the eg4electronics website has an RSD addendum to show you how to wire the CCA into the 18kpv, to eliminate dark start problems. Though, since you have a ton of the "RSS Transmitter" compatible panels, I suspect the dark start problem won't be a problem.

FilterGuy said:

Not quite true.

* There is a device that Solar Edge sells that will completely turn off the RSD function of the Solar Edge Optimizers. (I think it is called the Solar Edge Key). However... if you need RSD you will be out of luck.

* Solar edge does sell a controller that works with the optimizer. If you remove power from the controller, the optimizers will initiate a rapid shutdown sequence. The only downside is that the controller requires 120V power supply... so you have to plug it into the output of the 18K to make it all work. (When the 18K does a Rapid shutdown the AC turns off which initiates a rapid shutdown of the optimizers. That works OK but it introduces a greater possibility of a dark start problem. Here is the dark start sequence:

The inverter is powering the load overnight (No Grid power).
The batteries get low enough that the inverter shuts down
The Solar Edge optimizers shut down.
In the morning the panels can't turn on to charge the batteries.

With the Tigo optimizers and associated CCA controller, the CCA can be powered from the +/- 12V power supply the 18Kpv offers. This power supply will remain on till the batteries shut down.... even if the batteries get low enough that the inverter shuts the AC down.

Click to expand...

That sounds like a great way to power the Tigo CCA but my 18kpv doesn't put out ANY voltage on the 12+ and 12- lines. Is there something I have to turn on to make this happen?

jjww said:

That sounds like a great way to power the Tigo CCA but my 18kpv doesn't put out ANY voltage on the 12+ and 12- lines. Is there something I have to turn on to make this happen?

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There is a setting that you need to enable for this to work. I can take a look at your system if you'd like and make sure that RSD has been enabled. Just send me your station name and S/N and I can take a look.

EG4_Jarrett said:

There is a setting that you need to enable for this to work. I can take a look at your system if you'd like and make sure that RSD has been enabled. Just send me your station name and S/N and I can take a look.

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Many thanks to Jarrett for the timely help , Had to swap a couple of wires around on the main board and power is now present

jjww said:

Many thanks to Jarrett for the timely help , Had to swap a couple of wires around on the main board and power is now present

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Yeah, we've had a few go out this way.

Luckily, it doesn't damage anything, and it just takes the two pigtail connectors being swapped.

Glad your RSD is working!!

n2aws said:

Something to consider:

The most likely reason you'd run your batteries down to the point where your inverter were to shutoff, would be due to a grid outage.
If that is the case, the grid isn't going to resolve the "dark start" issue for you, until it returns. Thus, you may still want to consider some "dark start" options that don't involve the grid.

IMO: "dark start" solutions that involve "grid" in the sentence, aren't a solution. chicken and egg scenario.

Click to expand...

for dark start, you could add a 12v car battery or other connected to a 120v inverter to supply a 120vac source to the inverter, unless the AC source has to be synch'd to the grid ...that is down???

andyfromlc said:

for dark start, you could add a 12v car battery or other connected to a 120v inverter to supply a 120vac source to the inverter, unless the AC source has to be synch'd to the grid ...that is down???

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Many inverters won't start from 120v input, they need 240v. specifically offgrid type inverters. (Though, some do, to be fair).
So this *may* work for some inverters. You'd want to test it, however.

But yes, there are a ton of ways to work around the dark start issue. The specific point I was trying to make is.. "dark start" implies there is no grid available. So any "dark start" plan that involves connecting to the grid in some way, isn't actually a dark start plan.

Not sure if I mentioned it in this thread or not, but.. my panels are connected to DC charge controllers. The "rapid shutdown" transmitter is powered from 12-24v dc. so, in my case.. in my case, I can take the transmitter to one of the follwing 12v sources

Primary option: powered by the 12v output of the inverter. If it's still up and running (not really a dark start)
Backups (actual dark start):
#1) Solar powered gate openers (I have 2, each uses 2 12v batteries)
#2) my portable ham radio setup (solar powered, and AGM batteries)
#3) 3 different vehicles with 12v sources

So in my case, I'd take the RSD transmitter, connect it to any of those sources, and the arrays would all wake up and start charging the batteries. When sufficient charge, inverter can start.

@FilterGuy

If I use the TS4-A-2F, And install them on the modules per requirements, do I need to do anything else besides place the PV wires into the PV inputs within the EG4 18KPV?

Jdcarrol said:

@FilterGuy

If I use the TS4-A-2F, And install them on the modules per requirements, do I need to do anything else besides place the PV wires into the PV inputs within the EG4 18KPV?

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Nope, the 18Kpv has an internal transmitter that takes care of the rest.

Note: in some jurisdictions, the RSD initiator will need to be 'readily accessible' and that is often not where the inverter is. In this case, you can install an external initiator with wires to the inverter.

@FilterGuy just finding I need RSD receivers per code in my county. I’m on nem 3.0 and already going to be a bit oversized for my overall needs, however I will be charging an EV so more power during that time would be great. But cost and Roi are a major factor and now I’m looking at at ~$700 increase for the tigo dual rsd or ~1350 for the tigo optimizers that’s not including tap and cca. Are the optimizers with the additional cost in your opinion?

If you have shading issues go with the optimizers, if you like data go with the monitoring, if you like to save money go with the a2f modules.

Punk9721 said:

Are the optimizers with the additional cost in your opinion?

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1) The optimizers don't make a large difference unless the panels are at different angles or there are shading issues.

2) I am not a data fiend, so the extra data collection with optimizers is not an advantage to me, but other folks love to have the data.

3) I like to minimize the amount of electronics baking in the sun. The optimizers add complexity over the RSD receivers, which means lower long-term reliability. However, I do not have any data on that and I have not heard of issues with the Tigo Optimizers so I am unable to quantify the issue in any way.

4) I am willing to pay extra for quality, but I am fundamentally a cheap bastard, so I would not spend the money on optimizers unless there is a clear need (shading or angle issues).

Quattrohead said:

If you have shading issues go with the optimizers, if you like data go with the monitoring, if you like to save money go with the a2f modules.

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I can recommend these Tigo TS4-A-2F modules (each can switch 2 PV panels). Just installed 21 of them for 40 large panels (460W bifacial) organized in 8 strings. Because of time constraints, I had them sit more than 14 month in my garage and over the last 4 weeks I've tested them all with the final PV panel layout on each panel - luckily all are working (at least over a couple of days pre-testing).

The wire planning and management is the hell because every Tigo TS4-A-2F will handle 2 PV panels. I was required to build a lot of custom length PV wire extensions to be able to connect everything - it depends on the size of the PV modules and their factory wire length. Good wire planning is a must! In case you would use a TS4-A-F (this model can only switch one PV panel), the wire management would have been a lot easier but with a higher component cost because in this case, you need one TS4-A-F for each PV panel.

One hint:
Because of noise reduction (communication between the Tigo transmitter and each TS4-A-2F module will be done by communication over powerline), Tigo recommend to twist the PV+ and PV- wires over the whole length! This will add a good amount of diameter for each PV wire twisted pair! In case you plan conduit for the PV wires, choose at least the nexct larger conduit diameter to have enough space to pull some of these PV twisted pairs through the conduit. I had to replace some of the already installed conduits later with bigger ones because I've missed this twisted pair hint in the manual at the beginning.