Running aircon from 16A supply. More advice?

[John100156]

With the back-up switch closed you could see two battery chargers feeding into to the 12v and 24v banks/circuits, do you isolate the one charger before using the backup switch? If not, has it caused you any problems with chargers when run in this mode?

 

[BartW]

With the back-up switch closed you could see two battery chargers feeding into to the 12v and 24v banks/circuits, do you isolate the one charger before using the backup switch? If not, has it caused you any problems with chargers when run in this mode?

I don't remember that I had the backup switch on while 2 x 24V chargers were on, but I wouldn't expect a problem.

actually it is a similar situation like having the genny running while cruising, and having each 230V/24V charger in parallel with one alternator.
I'm sure we had that situation a few times, without any problem.

 

[halcyon]

I don't remember that I had the backup switch on while 2 x 24V chargers were on, but I wouldn't expect a problem.

Running two chargers at the same time will result in 'hunting'.

As long as the load on the chargers holds the voltage below the lowest regulation voltage, both chargers will run. When the lower regulation voltage is reached that charger turns off. The load on the remaining one goes up, resulting in a drop of voltage. Voltage falls below the lowest regulation point so the charger kicks in and cycle repeats till the one charger can cover the load.

But it depends in reality in charger design, it's size, and load on the system. as to how much a problem it is, or even if you see it.

Brian

 

[BartW]

Running two chargers at the same time will result in 'hunting'.

I’m pleased to confirm your explanation regarding Hunting,
because now I remember one occasion that I couldn’t understand what was happening, some time ago;

My new charger / invertor is permanently connected with the domestic bank
My old charger has a selector switch, and relais to connect it to the engine bank, or the domestic bank.
Since we installed that new charger last winter, this selector switch is of no use anymore, should be permanently in the “engine” position,
But in one occasion, that selector switch was accidently in the "domestic" = ” wrong” position,
And after switching “On“ the 230V supply to the charger,
The DC voltmeter on the domestic bank started fluctuating,
And the amp meter from the charge current started oscillating between 0 amp and..70(?)amp.
I realized it had something to do with the two chargers in parallel, as when I switched the selector in the “engine” position, all was working perfect again.
didn't do any further investigation then.
In future, I should substitute or lock that selector switch in the "engine" position.

Thanks again for sharing your knowledge, and for learning me something new about battery chargers

 

[John100156]

My concerns are as Halcyon suggests, whilst I fully understand the voltage division with series/parallel linking of the batteries, with switch one closed, it might exacerbate the problem causing further imbalance with a 12V charger (now covering three batteries) and the 24v charger across the 4 bank array, that shares two of its batteries with the 12V charger.

Still theory/practice are two different things - if it all works OK that's great, but I would have thought there might be issues particularly should one of the matched batteries in the triple 12V array have a problem. Interesting though (to me, sad that) glad you posted it up.

 

[BartW]

My concerns are as Halcyon suggests, whilst I fully understand the voltage division with series/parallel linking of the batteries, with switch one closed, it might exacerbate the problem causing further imbalance with a 12V charger (now covering three batteries) and the 24v charger across the 4 bank array, that shares two of its batteries with the 12V charger.

the backup switches are only used in case of a problem,

fe

in winter I had a broken 12V charger, 12V battery's empty (alarm system is 12V)
backup switch 1 was very usefull to start the genny then,


after a long period without electric (4weeks) arriving at the boat,
I needed to leave the marina with the boat quickly, but engine bank couldn't start because battery's not powerfull enough,
with backup switch 2 ON , I was able to start the engines,

but agree with you, that when these backup switches where not there when I purchased the boat a year ago,
I wouldn't have thought about it to fit these,

I'm not sure if anybody else has these switches, or never has a problem with empty battery's ?

In my other boat (9m Karnic) I alway's had a pair of starter leads,
and these have been usefull in several occasions.....

 

[John100156]

Totally understand - used infrequently, useful, I would certainly use them myself if they came with the boat..! Perhaps isolating one of the chargers should I do so. Sorry to OP for the thread drift.

 

[BartW]

Actually, in most dock sockets you must also turn a switch on after inserting the plug, therefore if you insert the plugs first, and turn the switches on afterwards, there's no exposure.
I don't disagree anyway, someone could still disconnect one of the plugs without turning the switch off first.
And do that in the rain barefoot, for good measure...

I humbly confess that I have made and used the much debated LBOK device this summer (thanks Mapism, twas your idea)
While I have a plan for a sophisticated and a bit more save LBOK box,
I just made a 32A female cable socket to: 2 x 16A male plugs + 1 x 16A female socket.
and have been using this satisfactory in my home marina in Toulon, where only 10A /per socket is available.

on some electric poles in Toulon, (luckyly not all)
each 16A socket has a individual earth leak detector per socket,
a good electric engineer will understand that the LBOK device doesn't work on these sockets

 

[MapisM]

I humbly confess that I have made and used the much debated LBOK device this summer (thanks Mapism, twas your idea)

LOL, I'm beginning to wonder if I shouldn't patent the LBOK. After all, I've seen the internal cabling of some chinese hairdryers which could be way more dangerous than the LBOK. And they were CE-marked too!...

Not sure of what you mean by earth leak detector, though. Do those sockets have individual RCDs (residual current devices)?
If so, it's pretty obvious that the load will never be perfectly balanced, and a 30mA leak is enough to make the typical RCD disconnect.

 

[DAKA]

If so, it's pretty obvious that the load will never be perfectly balanced, and a 30mA leak is enough to make the typical RCD disconnect.

The offending RCDs are easy to pull out with a good yank and can be substituted for a standard pencil eraser with a paper clip forced through the centre.











Please tell me this isnt a serious thread

 

[MapisM]

Please tell me this isnt a serious thread

Why? The OP asked for possible solutions of his needs.
He got various alternatives, including the simplest (LBOK), of which all potential dangers were discussed in detail.
And BartW confirmed that it worked for him.
I'm not saying that this is the most serious thread ever seen around here, but surely it isn't less serious than the average...

PS: incidentally, a proper electrical dock connection has also an onboard RCD, if that's what you fear.

 

[Deleted User YDKXO]

Why? The OP asked for possible solutions of his needs.
He got various alternatives, including the simplest (LBOK), of which all potential dangers were discussed in detail.

And here is what I actually did. I fitted a Victron Multiplus http://www.victronenergy.com/inverters-chargers/multiplus-12v-24v-48v-800va-3kva/ and I have to say that the jury is still out on how effective it is. The Multiplus is a combined charger/inverter that automatically senses the AC load required on the boat and reduces battery charging to compensate. It also automatically starts up the inverter when the shorepower AC is lost. Unfortunately, what it doesn't do (and I thought it did) is automatically sense the maximum available shorepower current and automatically start up the inverter to provide more current when the required current on the boat exceeds the max available shorepower current.
What you have to do is to go into the control panel menu and manually set the maximum current that the Multiplus will draw from the shorepower supply. This means 2 things. First you have to guess at what current the shorepower will trip out and thats not always 16A on a 16A supply, it's often less. Second you have to remember to adjust the setting back to 32A when you are connected to a 32A supply. There are also other issues. I have yet to find an alarm in the control menu which will warn you when shorepower is lost and the inverter cuts in. Also, for reasons I don't understand, the aircon on my boat doesn't seem to run properly on inverter current, even for short periods. Inverter supply is sufficient to run the air handlers and the seawater pump but not the actual compressor in the chiller unit which means that when shorepower is lost and the inverter cuts in, the aircon system starts to blow warm air around the boat. There is a 3rd problem as well. When I bought the unit, I wasn't told that to connect the charger section of the Multiplus to the generator, I needed an extra generator control module. So when I switch my gennie on and I want to charge the batteries, I have to remember to switch on the original charger fitted to the boat. It does mean I now have a back up charger on the boat but its another irritation. And just to complete the list of irritations, the company that fitted the Multiplus have put it in a location which blocks access to the outboard side of the port engine unless you are a double jointed midget. Its going to be a winter job to move it somewhere less inconvenient but thats not going to be easy because it means moving some very heavy duty cables.
I'm not going to decide just yet how useful the Multiplus has been for dealing with my original problem of running aircon from a 16A supply because I have yet to find my way around the control menu but what I can say now is that it certainly isn't the complete answer

 

[RupertW]

As a fellow Croatian boater I am extremely grateful to Deleted User for taking the trouble to set up this way.

Its hard to describe the irritation one feels when coming to your own annual berth with (everyone has 1 16amp socket, plus one 32 amp between 4), and finding that a couple of boats by you have got twin plugs, so they have all the amenities and you have none. Just as annoying when paying £80 for an overnight berth and finding the same.

Different languages and cultures make the obvious conversation harder to happen, and often the other owners are out and about anyway.

Most owners who use the two plug arrangement must be completely oblivious to their effect on others, or somehow think it's not their problem.

 

[Deleted User YDKXO]

Most owners who use the two plug arrangement must be completely oblivious to their effect on others, or somehow think it's not their problem.

Yes I once had a heated conversation with a German boater in Palmazana marina in August who was using 2 x 16A sockets, including the one allocated to my berth, which ended up with him jabbing his fingers into my chest and me pushing him away nearly into the water A full on diplomatic incident was only averted by the calming influence of my SWMBO and I only got my 16A supply after a few hours of running my gennie and filling his cockpit with exhaust fumes

 

[Forty_Two]

Do you have the remote panel with the knob that limits shorepower current draw? I do on my multiplus which controls from 0 to 16A.

Remember your chiller will draw maybe 5 times the running current on startup so am not surprised it won't run. I use a softstart unit for tricky supplies that helps greatly. I have never tried my 36,000 btu chiller on my multiplus without some shorepower as it cant possibly supply the startup amps needed. Mine runs at 15A but I have seen 40A at startup on my 240v ammeter and that will not show the short duration peak fully.

 

[MapisM]

Most owners who use the two plug arrangement must be completely oblivious to their effect on others, or somehow think it's not their problem.

Mmm... If the two plugs arrangement is so popular in Croatia, it means that the marinas have a problem, I reckon.
Fwiw, I never left my boat unattended with the two pugs connected.
It takes a few minutes for any decent A/C to cool down the boat, so I never leave it turned on unless someone is onboard.
And it's pretty obvious that I would have never pretended to be entitled to two sockets, when there's just one for each berth.
Same goes for the bow lines, which sometimes in Croatia create the very same problem.
If the offending boaters aren't around and/or are stupid, why not ask the marina, suggesting that no service, no payment?
Also the Croatians are pretty sensitive to this argument, IIRC.

 

[Deleted User YDKXO]

If the offending boaters aren't around and/or are stupid, why not ask the marina, suggesting that no service, no payment?
Also the Croatians are pretty sensitive to this argument, IIRC.

In the incident I experienced in Palmazana, I did ask the marineros to intervene but they weren't in the least bit interested, hence the dispute with the German

 

[Deleted User YDKXO]

Do you have the remote panel with the knob that limits shorepower current draw? I do on my multiplus which controls from 0 to 16A.

Remember your chiller will draw maybe 5 times the running current on startup so am not surprised it won't run. I use a softstart unit for tricky supplies that helps greatly. I have never tried my 36,000 btu chiller on my multiplus without some shorepower as it cant possibly supply the startup amps needed. Mine runs at 15A but I have seen 40A at startup on my 240v ammeter and that will not show the short duration peak fully.

I have a VE Net controller http://www.victronenergy.com/panel-systems-remote-monitoring/ve.net/ from which the Multiplus is set up and controlled. As I said I haven't yet explored it fully. Typical bloke problem of not wanting to read the manual
Yes I guess you're right about the chiller start up load. I didn't realise it was going to be as high as that. When you say you use a soft start, what exactly supplies the soft start?

 

[MapisM]

In the incident I experienced in Palmazana, I did ask the marineros to intervene but they weren't in the least bit interested, hence the dispute with the German

Yeah, it usually takes some dosh to interest Croatian marineros in anything.
I would have rather tried to complain (and use the "no service, no payment" argument) with the marina office.

 

[RupertW]

Yeah, it usually takes some dosh to interest Croatian marineros in anything.
I would have rather tried to complain (and use the "no service, no payment" argument) with the marina office.

But when you're on holiday an argument is the last thing you want to waste your time on. Spoils the mood.

Also, it may be the marina's problem but it's also the manufacturers and owners for getting a boat that requires two sockets when marinas are set up for one. I've no problem with somebody using two sockets but do get het up when they object if asked which socket I should unplug to let me have the one nearest my berth. Mostly I use very long extensions to avoid the issue but that doesn't always work and just moves the effects of the selfish behaviour down the pontoon.

No marina office or marinara has ever been interested even for my own annual berth. They just say, "up to you" or shrug, or once "the socket doesn't have your boats name on it".