I might just throw in a few pointers here - since I service Victron gear
for a well know Australian company.
Firstly like all brands - Victron too have their issues, but in all fairness they do design a good product. As for inverter and charger problems - I will point out the following, of which some details apply to any type and brand:-
As for Victron units, they come with factory default settings in the control boards -software which should be set up by the new owner in accordance with the system design. Many revert to licensed electricians rather than unlicensed Electronics
Technicians and often run into all sorts of problems when using electricians. There is a big difference between using a competent Electronics Technician and an Electrician - as far as technical ability. Unfortunately legal
licencing is the main hurdle to getting the job done by the system owner and so the Electrician often gets the job.
Added top this - Victron do not supply schematics, or circuit diagrams, to anybody outside the company, not even their own service agents. This restriction of technical data is to prevent competitors copying their products - intellectual copy-write.
Those techs like myself who service their gear, cannot get parts
after 3 years for any of their products, nor can we access circuit diagrams for component level board repair work and any technical questions which are thrown at their engineering staff don’t always get answered in detail, but often ignored or a watered down reply is given. We can though attain PCBs for replacement if the unit is under warranty.
On that note - the transfer switch PCB is the most common failing board - as it switches the AC mains generator
and inverter lines. And has a number of relays fitted. Lack of schematic information unfortunately ties our hands as to diagnosing the nitty-gritity faults.
Now as for inverters ( all brands here ) - many loads are not just resistive, but also inductive - and in such cases, an inductive load will draw at switch on, up to 8 times its operational current. In my Tech workshop, I have a Mitsubishi air-conditioner which pulls 550 watts from the 230 volt Ac mains. To reliably drive that air-con, the inverter needs a minimum continuous power of 3.5 kW, if not 4 kw to do the job without letup. Anything lkess will blow fuses
or result in electronic shut down of the inverter. On very small inverters is may result in the destruction of the unit.
A 24 volt, 3000 watt Victron Phoenix pulls a measured 170 amps at 24 volts at switch on with a 550 watt air-con on the inverter outpur. During the air-cons normal running phase, the inverter ( loaded with the compressor
from the air con ) pulls 22 amps at 24 volts Dc.
Do the sums and you'll find the load requirements for an inverter on inductive loading is massive.
As I recall
, Victron rate their inverters at about 6 times the nominal output on inductive loads, which I find a bit over rated. This output is not continuous but very short transient for too short for many air compressor
start-up periods. Additional to this, all Victron inverters use some form of heavy toroid transformer in the inverter output, which is a good thing; unlike switch-mode inverters which lack this big transformer and are virtually direct drive to the load.
The magnetic flux “stored” in the transformer core
during normal inverter operation aids in driving heavy inductive loads. Items like - microwave ovens, most refrigerators, air conditioners, large motor
driven winches and pumps, etc; are all inductive loads. Items such as navigation
, lights, heating
devices and radios, etc; often are resistive loads. Inductive loads needs lots and lots of current to activate them, while resistive loads don’t, as the voltage pressure is in phase with the load current, aiding its operation.
This leads me to my final point on charging ( all brands which employ a charge curve profile and some sort of voltage sensing electronics).
If you try and charge your batteries whilst driving heavy loads, or cranking your engine - you are guaranteed to cook your batteries and over heat your charger. The amount of people who call me each day at work blaming the charger as destroying their batteries - is ridiculous. Older simpler transformer-rectifier chargers would be more forgiving with engine cranking while the charger is running, but not so with the more advanced types, such as the Victron units.
If you load a battery with say a bow thruster pump of which can pull a peak current of up to 800 amps, while charging your batteries - your asking for trouble.
The issue is – the battery terminal voltage is being pulled down by the load and the charger sees this as a discharged battery ( and not a loaded battery).
As a result, it supplies bulk mode current into the battery bank ( some single
victron charger units will pass 120 + amps into a battery ) at the same time your trying to extract another 300 amps out of the same battery with a bow thruster pump ( as an example ).
The 2 current flows clash and produce friction, which produces lots of heat. If the charger does not overheat in the process, it causes the battery to go into thermal runaway and create a virtual core
melt down, as its battery cell voltage falls and it draws more charge current – some what like in a nuclear reactor melting down internally.
If a fire does not start in the battery bay, the battery bank at least melts and collapses ( flooded lead acid cells are a bit more forgiving, as they can be topped up with water
; but even so, you can still kill them this way).
The charger may survive; - but if its mounted in the engine room, or some concealed and restricted location for air flow and low ambient temperature, its bound to be problematic if it does not fail. Electrolytic capacitors dry out and other parts start to fail with excessive heat stress, eventually killing the charger and inverter.
To get around this problem of battery destruction, I recommend 2 sets of batteries in place - one set always on charge and the 2nd set driving the loads. When the load battery drops to its critical value, its swapped over to the charger and the freshly charged battery bank goes into work supplying the loads. A simple, but expensive fix to a common problem.
A second solution is to, not run any heavy loads whilst charging your batteries.
I trust this may clear up some technical issues for some.