2 hours ago, Jaco de Jongh said:

 

How do you set the names of the MPPTs?

1 hour ago, plonkster said:

With smart networking you can make the solar chargers talk to each other and behave as one. It's not used with an ESS system though. With ESS you let the Venus device control the solar chargers. So for ESS... it's just BlueTooth.

I read something last night in the Victron-Pylontech guide about the MPPT shutting down when the Venus goes offline? Is there a setting for that in ESS? The smart networking thing sounds like something that could kick in if the Venus goes offline?

Edited September 5, 20197 yr by PaBz0r

9 minutes ago, PaBz0r said:

How do you set the names of the MPPTs?

From this page, highlight the MPPT -Right Arrow- Down to the "Device" line - Right Arrow - Down to " Name" Line - Space Bar -Enter your Name and end with Space Bar.

4 minutes ago, PaBz0r said:

MPPT shutting down when the Venus goes offline?

I am not aware of that. My case the MPPT is set to deiver 100amps to the batts.
ESS regulates the charge current at 60amps.

So I am acutely aware that if the Venus is off, I must switch off the panels.

14 minutes ago, The Terrible Triplett said:

I am not aware of that. My case the MPPT is set to deiver 100amps to the batts.
ESS regulates the charge current at 60amps.

So I am acutely aware that if the Venus is off, I must switch off the panels.

Maybe I should try it?

18 minutes ago, PaBz0r said:

Maybe I should try it?

And here I sit and wonder: Why have you not tried!?

 

And I see the trick lies in this error code: error #67: no BMS.
So I still need to be very aware as there is no BMS on Trojan's ... at least not that I'm aware of.

21 minutes ago, The Terrible Triplett said:

And I see the trick lies in this error code: error #67: no BMS.

Yup. That is what happens. The MPPT does not switch off completely. What it does is go into a kind of float mode, with a reduced voltage. It does this so that in cases where the BMS disconnects the battery, the MPPT can serve as a power supply for other things (such as your Venus device). But it won't charge the battery until either the comms with the BMS returns, or you switch off the BMS setting.

8 minutes ago, plonkster said:

Yup. That is what happens. The MPPT does not switch off completely. What it does is go into a kind of float mode, with a reduced voltage. It does this so that in cases where the BMS disconnects the battery, the MPPT can serve as a power supply for other things (such as your Venus device). But it won't charge the battery until either the comms with the BMS returns, or you switch off the BMS setting.

 

So in saying that, should I then worry what the max amps are set at on the MPPT?  

1 minute ago, PaBz0r said:

So in saying that, should I then worry what the max amps are set at on the MPPT?  

The system will never override the max set on the MPPT, so it uses the lesser of what the battery asks for or what your MPPT can deliver. So the best is simply to not set a limit at all and let the battery manage it. No need to worry, because the solar charger stops charging if it loses comms.

3 minutes ago, plonkster said:

 because the solar charger stops charging if it loses comms.

I would worry if using lead acid with a BMV...  Would it keep the batteries alive? 

 

19 minutes ago, plonkster said:

What it does is go into a kind of float mode, with a reduced voltage.

You're gonna have to explain a bit more?

10 minutes ago, plonkster said:

The system will never override the max set on the MPPT, so it uses the lesser of what the battery asks for or what your MPPT can deliver. So the best is simply to not set a limit at all and let the battery manage it. No need to worry, because the solar charger stops charging if it loses comms.

Thanks, was confused and clipped my Max Amps due to worrying about it. Now with the strings properly fused I can go "oop ketels"

4 minutes ago, Ironman said:

I would worry if using lead acid with a BMV...  Would it keep the batteries alive? 

Yes! It switches to a nominal voltage, in a 48V system it will provide 48V. So lead acids will get at least a maintenance charge... but then you also won't use a BMS with lead acids so this is a moot issue.

5 minutes ago, Ironman said:

You're gonna have to explain a bit more?

While in error #67 (BMS lost), the MPPT makes 48V (or whatever it is configured for). Since the battery is normally at a voltage higher than that, it will not charge. BUT... if the BMS disconnects the battery, then the voltage on the DC bus is held high enough so that the DC loads are powered. DC loads are things like the Venus device. That means it reains alive and can log to the internet and you can even log in remotely and reset things. If the MPPT didn't hold that nominal voltage... everything would go dead until someone could physically go there.

 

10 minutes ago, plonkster said:

 won't use a BMS with lead acids so this is a moot issue.

So is the BMV700 seen as something different than a Pylontech BMS by the Venus devices?

12 minutes ago, plonkster said:

everything would go dead until someone could physically go there.

I lost a whole set of Royal batteries (8 * 105ah) due a burnt contactor on a Microcare 60A MPPT.  The batteries could not disconnect from the tiny load of a 12V alarm system, and ran completely dead.

We don't visit that house in summer due to Malaria. Could have been dead for 4 months - we will never know. Replaced the contactor and the MPPT is still going three years later.

1 hour ago, plonkster said:

The system will never override the max set on the MPPT, so it uses the lesser of what the battery asks for or what your MPPT can deliver. So the best is simply to not set a limit at all and let the battery manage it. No need to worry, because the solar charger stops charging if it loses comms.

During bulk charging, having no BMS, MPPT set to max of it's 100amps, I've seen 100amps hitting my 225ah bank.

Only happened twice, I swear:
Once because I never thought of it - even though Plonk warned me seeing as I had a very small bank AND wanted to use all the panel power for the house.
Second time just to see if it will still happen @PaBz0r 🤣

Now I have a 450ah, so less worried.
And soon a 950ah bank - 22.8 kWh or being lead acid 11.4kWh.
And o boy, is THAT going to cause consternation here on PF!

I'm going to push some more limits and beliefs and rules for as they say, "rules are like bones, meant to be broken" coupled with "a Boer (farmer) makes a plan!".

But more on that later ... pictures will open THAT discussion.

Point is, with a 950ah lead acid bank the 24v 100amp caution will be over - IF my idea works - so no need for a BMS then see. 🙂

43 minutes ago, Ironman said:

So is the BMV700 seen as something different than a Pylontech BMS by the Venus devices?

Yes and no.

Both are seen as "battery services". But the Pylontech battery is "intelligent". They have some things in common: both types sends voltage, current, temperature (optional for BMV) and SOC information. But inteliigent batteries additionally also send charge voltage and charge/discharge current limits.

Where there is an intelligent battery, those limits are communicated to the Multi and the solar chargers. a BMV is what you might call a "dumb" battery service and does no such thing.

I have a borehole with a 1.1kw single phase motor 50l pressure vessel and a pressure relay that switches it on when water pressure gets too low. It has a large startup surge that will cause issues.

is there a control circuit that uses something like this schneider unit to soft start the motor? It is a soft starter for that size, and needs a dc or ac control signal. My pump’s current control circuit includes a phase angle detector to protect against running dry. So, preferrably need a whole control circuit for a borehole pump, but it must eliminate the startup surge. 

9 hours ago, Ironman said:

I have a borehole with a 1.1kw single phase motor 50l pressure vessel and a pressure relay that switches it on when water pressure gets too low. It has a large startup surge that will cause issues.

That should have a startup surge of maybe 5kw, which isn't THAT bad. It does however work a 3kVA hard.

The one issue with soft starters -- and this is what I read, not personal experience -- is that it has to ramp the voltage fast enough to overcome the initial resistance, and then ramp it from there. That means in many applications, it still requires two thirds or so of the initial inrush to get it moving. It is not nearly as effective as using a VSD (which is of course even more expensive).

Perhaps look at a DAB E.Sybox, which is fairly expensive, but the larger unit is a 1.5 liter inverter pump?

So I got the  Carlo Gavazzi ET112 working today, using the Venux GX to report back tot he VRM.  Connecting direct to the Venus GX from my phone is the best thing! I get a second by second update on power consumption.  Walking around the house and testing every single thing is very eye opening:

- A hairdryer (1700W) vs hair straightener (35W) ...  

- Borehole pump: 1100W

- Geysers 1800W each

- lights: many LEDS are 60W, old style lights (50W 12V) add up very quickly.

 

I immediately took all the heaters from my property and put them on the street.  Whoever can afford to use them can take them.

Turns out that I have a 1500W borehole pump - even larger startup surge... 

Heaters are like sweets - if you have it at your house, you will eat sugar. If not, you just get used to it.

 

13 hours ago, Ironman said:

Heaters are like sweets - ...

Ok, so you are now on the phase of finding the offending loads, getting really informed, facepalming and all that right?

As you will discover in due course, SWAMBO's tend to be the heaviest users of electricity and that they don't take it well when put next to the heaters outside. Word of advice: Stop before you go there as YOUR life will become quite "unsustainable" i.e. like with frequent trips to hospital and all that see. 🙂

We need them more than they need us see.

I think I did it the smart way - moved the council account to be one of her expenses about a year ago (also more tax efficient). Just one winter later and she is the one pushing hardest for savings 🤐. 

It does mean I will be funding the capital of the solar system, but at least it is an investment with a long term upside. And it will keep me entertained.

In the end it is OUR money - seeing where it really goes is the ‘getting really informed’ part.

 

On 2019/09/07 at 5:26 PM, Ironman said:

I immediately took all the heaters from my property and put them on the street.  Whoever can afford to use them can take them.

I'm actually looking for one. I occasionally need a load to test things with...

At the moment I use my heat gun.

On 2019/09/08 at 8:26 AM, The Terrible Triplett said:

facepalming and all that right?

So today I inspected my geysers properly and found that the third geyser had a closed valve on the solar panel feed line.  This means that I got zero energy from the sun over the last 5 years for that geyser...

 

2 hours ago, Ironman said:

This means that I got zero energy from the sun over the last 5 years for that geyser...

Now does that not just simply p... sorry ... meant to say tick you off?

I need to apply earthing to the solar panel frames. 

What hardware is available for that? What size cable should I use?