Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: HillTimeBandits on December 09, 2017, 05:04:38 PM

Title: Hi, Thanks , Hello proper, and advice sought!
Post by: HillTimeBandits on December 09, 2017, 05:04:38 PM
Hi all.
Thanks for the member add. Great to be here. I've been hovering over this site for ten years, browsing threads, reading stories, following links and basically in awe of the amount of knowledge, experience and wisdom shared within the  forum.
Secondly, a little background on myself and family (be they persons or equipment).
We've been living off-grid in west Stirlingshire for nearly 9 years now. This was by way of house inheritance really, as we were starting a family.
It all started fairly simply i.e the power supply - with a couple of Yanmar gensets, but since then all  (house, family  power supply) have  expanded significantly.
Our main power now is a ever reliable 9kw Lister Petter (with a small Pramac as back up), running into a 24v Victron multiplus 3kw/70amp unit with an additional 50amp Victron Skylla alongside - this all pumps into and takes out of a 1050ah (c5)  24v  (12 x 2v) flooded battery bank.
We also have a small solar array of about 1.5kw, which is fed direct into the batteries via some Fleebay controllers.

Problems - Recently (last 6 weeks)  the Multi (out of warranty) has been playing up and shutting down claiming overload, when very little load present. It also has shut down when genny running!

Currently (as of two days ago) its disconnected and we are running direct of generator as backup inverter (fleebay again)  has died also.

My thoughts and experiences thus far -
Don't  feel much love for combi units as when one part goes everything goes, and are expensive to replace.
Would prefer to split Inverter and chargers, although unsure how best to manage switch overs.
Plan to expand solar array to maybe 3kw and thus wonder about reliable solar inverter to be main beast on site.

So any experiences? , good or bad, please on
1) -  a split system with chargers, inverters and solar controllers
2) - rely on combis with a solar controller; or
3) - move to a solar inverter with all inputs and outputs such as a Conversol ( although unsure of its reliability.

Hope this is not too forward, as its my first time to post on a forum, so please set me straight or shoot me down, if needed.
I should add, I married into a family of electricians, so they will be installing and advising on electrics.
Thanks again

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: biff on December 09, 2017, 05:15:25 PM
Welcome to the forum HTB,
                           I am sure the members are mulling this over and thinking of a suitable answer or answers,,
I will pass on this one because i simply don,t have the experience but don,t worry,,Help will be along soon.

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: camillitech on December 09, 2017, 05:31:37 PM
Hi and welcome,

personally I'd stick with a combi unit and if you want one you can repair yourself get an Outback. The Voltacon inverters are OK, I've not really heard anything bad about them in this country. A few issues in Australia but I suspect that's more to do with their amount of sun and a poor MPPT charger in the unit. I've fitted a couple, one did go bad but was repaired under the 5 year warranty. Wouldn't have one myself for a main unit though as they only have small battery chargers.

I certainly wouldn't bother with solar inverters or 'AC coupling' unless you have a large sprawling property and it's already wired up. I've been 'off grid' since 1985 and not replaced any combi units (SMA, Outback, Studer) though my Trace did require a repair after ten years.

What you must do as a matter of urgency is stick loads more PV up, it will make your generator all but redundant if done properly.

Good luck, Paul

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: todthedog on December 09, 2017, 05:53:40 PM
Hello Edna and welcome to the foum

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: offthegridandy on December 09, 2017, 07:06:16 PM
Hi Enda and welcome.

I will always buy the best electronic gear I can afford, I've used Outback for years now, I had an inverter develop a fault and the entire box was replaced within 5 days, the 5th day being christamas eve; guess what I was doing on christmas day that year. It's good gear but not the cheapest.

Our house is regularly unmanned during the day and sometimes for a day or 2, with fridges and freezers holding months worth of produce i don't want failures.  However if you are around most of the day to tweak and fiddle you may be able to get away with lower cost gear, if there's a failure your on hand to deal with it.

As Paul says if you can maximise the PV over the year you will cut the genny run time significantly.

I have the outback inverter /charger at the heart which moniters battery SOC and supplys the AC grid in the house.  An Outback FM80 solar PV CC with around 2600w of panels. My lister genny is autostart taking it's signal from ther Invertor/charger.  Genny can start to support a large load or to run a charge cycle for the batteries.  On a charge cycle the charge rate will moderate depending on any RE input at the time ie wind and or PV.  At that point over production from the genny can be diverted to water or space heating.

I'm sure other members  are equal fans of other brands,  if your concerned about failure you could look to see who is your nearest physical stockist, of your chosen brand.  

Good luck.



Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: HillTimeBandits on December 10, 2017, 06:12:55 PM
Hi guys and thanks for replies.
Good advice for more solar  Paul and will be hoping to get that up next year, but got a few hoops to jump through to get  there.
Thanks for advice Andy, and looking at your set up, we are pretty similar and I have had my eye on the Flex for when the panels expand, i may come back to you for more advice re that set up.
After a few days swearing at combi units, it looks like its still the best set up and will probably stick with that.
As you say Paul, the Voltacon, does seem fair, but i've been burnt too many times with cheap Chinese s**t and am reluctant to go down that route again. I threw it in there, as it was suggested to me and really looking for a good reason not to get it!
Looking at the outback, its coming in the same price as the Multi on the CCl website. Its good having these guys in Glasgow and  We bought most of our kit through them so will probably stick with them.

Also, does anyone have any suggestions on repairing a Victron Multi apart from shipping it to the  Netherlands via CCL? where its a  complete unknown for price on repair. Is there any UK based repairers that may be a better option?
Thanks again.

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: kibi on December 13, 2017, 01:17:52 PM
I'm curious as to the cause of the overload condition on the Multiplus. Is the "Overload" LED lit in combination with "Low Battery" by any chance?
If the quality of the connections anywhere on the DC side have degraded, then the Multiplus will sense excessive ripple on it's DC input which would cause problems. Even light loads on the AC side can cause excessive DC ripple if battery terminal connections or cabling are not in tip top condition. Again, when charging the battery, poor connections can cause excessive DC ripple and cause the Multiplus to shut down when the generator is running.
It may be worthwhile investigating faults or even performing a little maintenance on the DC side (if you have not done so already) before going through the hassle of sending the Multiplus away. It's be a shame to install a replacement unit only to discover that the fault remains.
The Victron kit is very good and it's more than likely reporting a genuine fault rather than being faulty it's self.

The combination units do offer great flexibility to enable more complex systems should you wish to consider such a setup in the future. I too am an advocate for DC coupled PV.

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: camillitech on December 13, 2017, 05:16:30 PM
Years ago my Trace SW4548e kept shutting down randomly with the red light saying 'overload' illuminated. Drove me nuts as the thing was never overloaded and happened on every circuit. One day I just happened to be in the inverter shed when it happened and I heard a crack from the wall behind it, turned out to be a cable gnawed through by mice.

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: HillTimeBandits on December 28, 2017, 04:15:44 PM
Hi and thanks for replies guys.
Been crazy with work, then flu, until about now.
Thanks for advice kibi, re: DC ripple and mice attack, camiltech. Connections are a little aged and probably could do with some TLC about now.
I have purchased another VE Multi, the 5000kw 120 amp unit. This will be the primary inverter, with the older 3kw unit for standby.
Regards for now.

Title: Re: Hi, Thanks , Hello proper, and advice sought!
Post by: Scruff on December 30, 2017, 02:03:54 PM
I keep it modular because I never met a combi with a decent charger or charge controller. Most manufacterer's get the inverter end right.
I have a combi that I only use the inverter side. I have another in rehab and I've no intention of using it's charger either. Combis cost the same as stand alones so they can be useful for redundancy.

Overload could be a problem in the current sense or temp sense department or installation impedence. I'd start by blowing out the gubbins with an air compressor. Then I'd measure the load and cable temperatures next time it misbehaves.