I posted about failure of my Phoenix 12/30 charger of 2013 vintage.
One of the reasons I selected this product was that the negative output is not connected to mains earth within the charger, so that the output ‘floats’.
I am rather assuming that I’ll need to replace this charger and am wondering about modern replacements that meet this requirement.
Would appreciate if anyone could confirm whether the DC negative is connected to mains earth (or definitely not) in the following products;
Smart IP43 Charger 120-240 V
Smart IP43 Charger 230 V
Blue Smart IP67 Charger Waterproof
Blue Smart IP65 Charger
I think the Victron options to replace my Phoenix 12/30 are
(a) Smart IP43 Charger for two ‘main’ batteries and a Blue Smart IP65 or IP67 for the start battery
(b) Three separate Blue Smart IP65 or IP67 chargers, one per battery.
Whatever I end up with, I need floating DC outputs and no fans. And I do like the idea of Bluetooth remote control.
Any help on this would be appreciated, since I can’t find the information in the manuals.
Do you have problems with a residual current circuit breaker at the AC input or why does the DC output have to ‘float’?
I maintain that no switching power supply really ‘floats’ … There are always connections to the input.
Merry Christmas Matthias … so you’re not really ‘off’ either …
I would also have said that they are all ‘isolated’ but with switching power supplies there is always this ‘feedback’ to the input. You should have galvanic isolation in the boat anyway, shouldn’t you?
Of course I agree with you about the ‘designation’ … but
That’s exactly the mistake, but it doesn’t matter here.
I think the author of the article means something else.
There is no real galvanic isolation with switching power supplies.
As soon as I have a power supply unit with a Euro plug, I have no real connection to the PE and no earthing of the power supply unit.
The secondary side can have a ‘feedback effect’ on the input. An HF transformer can generate voltages of over 80V to earth. If the boat now has an earthed busbar from the negative side, there MAY well be interactions with the ‘real’ earth.
But that would be going far too far here.
True isolation is only possible with an isolating transformer.
That “feedback” is generally through an optocoupler.
The residual current some usually measure is because of the Y capacitors which can also “light-up” that “live probe”.
If you can live with the AC line “noise”, take out all Y capacitors and you’ll have a true isolated SPS.
As it should be. These are times to spend with the family, not at work.
As per the OP first post, the charger’s page says as per picture below.
And I think that Victron knows about the boat owners problems and it won’t say something like that if it could be a problem…
Talking about small boats with non-metallic hulls, it’s now quite common to find newer boats where mains earth is bonded to DC negative. Indeed some modern standards require this and so many modern boats will be delivered with this connection. Some battery chargers make this connection.
A problem is that connecting mains earth to boat anodes (via DC neg) can cause excessive anode depletion. My (rather old) boat was supplied un-bonded and I’ve kept it that way, with mains supplies protected by dual-pole CBs and RCDs and no galvanic isolator (which I don’t really trust anyway). I generally use double-insulated products and avoid exposed earths. Obviously, there’s a whole topic about the risks of mains power on boats and earthing thereof.
Ludo said “All products in a plastic housing and with a (European) two prong connector are isolated.” I’m in the UK and not certain that any product would come with a two prong connector; if it did, I’m sure you’d be correct.
Even my old Phoenix with metal case has the output floating so I’m hoping that this product philosophy has been continued. The old Phoenix has never been great for me anyway - pre-sales I was told the fan would only run when needed, but in practice it never stopped, later I was then informed that the pre-sales information was incorrect but by then it was installed.
I can obviously order some chargers, test and return if not suitable, but if any of you guys with product access can confirm for any of the models I’d listed, that would be appreciated.
PS - Obviously the best approach to isolation is an isolation transformer, but that’s OTT when a charger with a floating output would suffice!
In Europe, a double insulated appliance must be labelled Class II or double insulated or bear the double insulation symbol: ⧈ (a square inside another square).
That is the problem with this topic:
We are talking about galvanic isolation NOT class 1 or 2 protective insulation
One does not necessarily have to include the other. Especially with the HF power supply units mentioned above.
Yes, indeed. I’m not that concerned with whether a battery charger is double-insulated, since installed generally out of reach in my view the risk is low. But I would always try to use a double-insulated toaster or kettle.
@TheRhino an interesting topic and good feedback from the knowledgeable “hive”. The important aspect of the discussion is of course DC isolation. The galvanic current feared by boat owners plugged into mains at a marina is DC. A DC connection to other boats in the marina via the grounded connection is the issue to overcome so relatively high impedance capacitive AC connections are not significant issue.
A friend checked his charger model
Victron Phoenix Smart IP43 Charger 12V 50A 3 Outputs (120-240V input) and has confirmed that the output is floating with respect to mains earth.
I’d really like confirmation that this is also the case for the Victron Phoenix Smart IP43 Charger 12V 30A 3 Outputs (230V input)
These are times to spend with the family, not at work. 
